Method for evaluating egg-laying performance of Leizhou black duck

Abstract

The application discloses an evaluation method of egg laying performance of Leizhou black duck. The application is aimed at Leizhou black duck, and finds that 5 SNP sites are significantly related to the age of starting laying of Leizhou black duck; 2 SNP sites are extremely significantly related to the body weight of starting laying of Leizhou black duck. It is further found that a haplotype has low starting laying age, high starting laying body weight and high egg laying quantity, so that individuals with low starting laying age, low starting laying body weight and high egg laying quantity can be screened from the advantageous genotypes of the 7 SNP sites, so as to improve the egg laying performance and economic benefits.

Description

Technical Field

[0001] This invention relates to the field of animal breeding technology, and more specifically, to a method for evaluating the egg production performance of Leizhou black ducks. Background Technology

[0002] China is a major duck-raising country, accounting for approximately 75% of the world's total. While it boasts abundant local duck breeds, these breeds often have low reproductive rates. As the number of ducks raised by farmers increases, production efficiency is decreasing, making it crucial to reduce the loss of local breed resources a pressing issue. The Leizhou Black Duck is a widely distributed duck breed on the Leizhou Peninsula in China, characterized by strong adaptability, disease resistance, a long peak egg-laying period, early egg age, rich trace element content in its eggs, and tolerance to roughage. As a high-quality local duck breed, its genetic diversity provides excellent genetic material for improving meat and egg performance and environmental adaptability. However, due to widespread free-range farming by farmers and the random production of commercial ducklings, the lack of a standardized artificial breeding system leads to significant differences in individual breed and feather color. This unstable genetic makeup and declining egg production quantity and quality put the Leizhou Black Duck at a disadvantage in market competition.

[0003] Etoposide-induced 2.4 protein (EI24), also known as p53-induced gene 8 (PIG8), encodes a six-span membrane protein located in the endoplasmic reticulum (ER). Researchers have found that EI24 can inhibit cell growth and promote apoptosis, and its absence inhibits DNA damage-induced cell death. When DNA damage occurs, cells initiate multiple response pathways, including DNA-PK and ATM / ATR, to activate DNA repair, cell cycle arrest, and / or apoptosis. Inappropriate or insufficient DNA damage responses can lead to gene mutations and cancer development. A key player in the DNA damage response is the tumor suppressor p53, which promotes cell cycle arrest and DNA repair in moderate DNA damage but promotes apoptosis in severe DNA damage. EI24 expression is highly induced by the tumor suppressor protein p53, and EI24 is considered a tumor inhibitor among p53's target proteins. Furthermore, EI24 is frequently lost or mutated in various cancers.

[0004] Studies have shown that EI24 specifically binds to Bcl-2, a known cell death regulator found in mitochondria, the ER, and the nuclear membrane. This study, through immunoprecipitation and other in vitro and in vivo protein-protein binding assays of EI24-Bcl-2, indicates that EI24 binds to the BH3 domain of Bcl-2 via its N-terminal region, potentially influencing apoptosis.

[0005] Furthermore, immunohistochemical analysis showed that EI24 deficiency was associated with the invasiveness of breast tumors. These results indicate that EI24 induction leads to the regulation of Bcl-2 activity and / or function in the ER, and that this regulation contributes to the apoptosis process. EI24 may help prevent tumor spread in breast cancer, consistent with its initial suspected role as a tumor suppressor, and also raises the question of whether the differential expression of EI24 mRNA in the ovaries of high- and low-yielding Leizhou black ducks affects the reproductive traits of Leizhou black ducks. Summary of the Invention

[0006] The purpose of this invention is to overcome the above-mentioned shortcomings of the prior art and provide a method for evaluating the egg production performance of Leizhou black ducks.

[0007] This invention discovered the correlation between the genetic polymorphism of the EI24 gene and the egg production performance of Leizhou black ducks. Furthermore, direct sequencing was used to verify the relevant molecular markers of the EI24 gene, laying the foundation for the further construction of a high-yield core group of Leizhou black ducks.

[0008] The first objective of this invention is to provide a reagent for evaluating the egg production performance of Leizhou black ducks.

[0009] A second objective of this invention is to provide the application of the reagent in the preparation of a kit for evaluating the egg production performance of Leizhou Black Duck and / or a method for evaluating the egg production performance of Leizhou Black Duck.

[0010] The third objective of this invention is to provide a haplotype molecular marker for the egg production performance of Leizhou black ducks.

[0011] A fourth objective of this invention is to provide a detection reagent for the haplotype molecular marker.

[0012] A fifth objective of this invention is to provide the application of the haplotype molecular marker or the detection reagent in the preparation of a kit for evaluating the egg production performance of Leizhou black ducks and / or a method for evaluating the egg production performance of Leizhou black ducks.

[0013] The sixth objective of this invention is to provide a kit for evaluating the egg production performance of Leizhou black ducks.

[0014] The seventh objective of this invention is to provide a method for evaluating the egg production performance of Leizhou black ducks.

[0015] The eighth object of the present invention is to provide the application of one or more of the reagents, the haplotype molecular markers, the detection reagents, or the Leizhou Black Duck egg production performance evaluation kits in the auxiliary selection of egg production performance traits of Leizhou Black Ducks or in the molecular breeding of egg production performance of Leizhou Black Ducks.

[0016] To achieve the above objectives, the present invention is implemented through the following solution:

[0017] A reagent for evaluating the egg production performance of Leizhou black ducks, wherein the reagent detects one or more of the following sites:

[0018] SNP locus 1 is located at NC_051796.1:537426, which is nucleotide 537426 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: GG, GT, and TT.

[0019] SNP locus 2 is located at NC_051796.1:537384, which is the 537384th nucleotide on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0020] SNP locus 3 is located at NC_051796.1:537333, which is nucleotide 537333 on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: TT, TA, and AA.

[0021] SNP locus 4 is located at NC_051796.1:537284, which is the 537284th nucleotide on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0022] SNP locus 5 is located at NC_051796.1:537277, which is nucleotide 537277 on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0023] SNP locus 6 is located at NC_051796.1:537187, which is nucleotide 537187 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: CC, CA, and AA.

[0024] SNP locus 7 is located at NC_051796.1:537058, which is nucleotide 537058 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: CC, CT, and TT.

[0025] The egg production performance refers to the age at first laying or the weight at first laying.

[0026] Individuals with the TT genotype at SNP locus 1 had a significantly higher age at onset than individuals with the GT genotype.

[0027] Individuals with the AA genotype at SNP locus 2 had a significantly higher age at onset than individuals with the GA genotype.

[0028] Individuals with the AA genotype at SNP locus 3 had a significantly higher age at onset than individuals with the TA genotype.

[0029] Individuals with the AA genotype at SNP locus 4 had a significantly higher age at onset than individuals with the GA genotype.

[0030] Individuals with the GG genotype at SNP locus 5 had significantly lower birth weights at birth than individuals with the AA genotype.

[0031] Individuals with the GG genotype at SNP locus 5 had significantly lower birth weights at birth than individuals with the GA genotype.

[0032] Individuals with the AA genotype at SNP locus 6 had a significantly higher age at onset than individuals with the CA genotype.

[0033] Individuals with the CC genotype at SNP locus 7 had significantly lower birth weights at birth than individuals with the TT or TC genotypes.

[0034] Preferably, the reagent shown is a primer.

[0035] More preferably, the nucleotide sequences of the primers shown are as shown in SEQ ID NO:1 to 2.

[0036] Upstream primer: 5′-GCCTTTGCTGTCGTGATAT-3′ (SEQ ID NO:1),

[0037] Downstream primer: 5′-ATGTTCCCGTCACCTACCT-3′ (SEQ ID NO:2).

[0038] The application of any of the reagents described above in the preparation of the Leizhou Black Duck egg production performance evaluation kit and / or the Leizhou Black Duck egg production performance evaluation method is also within the scope of protection of this invention.

[0039] This invention also claims protection for a haplotype molecular marker for the egg production performance of Leizhou black ducks, said haplotype molecular marker consisting of 7 SNP sites:

[0040] SNP locus 1 is located at NC_051796.1:537426, which is nucleotide 537426 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: GG, GT, and TT.

[0041] SNP locus 2 is located at NC_051796.1:537384, which is the 537384th nucleotide on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0042] SNP locus 3 is located at NC_051796.1:537333, which is nucleotide 537333 on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: TT, TA, and AA.

[0043] SNP locus 4 is located at NC_051796.1:537284, which is the 537284th nucleotide on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0044] SNP locus 5 is located at NC_051796.1:537277, which is nucleotide 537277 on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0045] SNP locus 6 is located at NC_051796.1:537187, which is nucleotide 537187 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: CC, CA, and AA.

[0046] SNP locus 7 is located at NC_051796.1:537058, which is nucleotide 537058 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: CC, CT, and TT.

[0047] The age at birth of individuals with the following genotypes were significantly lower than that of individuals with the following genotypes: SNP1 genotype GG, SNP2 genotype GG, SNP3 genotype TT, SNP4 genotype GG, SNP5 genotype AA, SNP6 genotype CC, and SNP7 genotype TC.

[0048] The age at birth of individuals with the following genotypes—GG at SNP locus 1, GG at SNP locus 2, TT at SNP locus 3, GG at SNP locus 4, AA at SNP locus 5, CC at SNP locus 6, and TC at SNP locus 7—was significantly lower than that of individuals with the following genotypes—TT at SNP locus 1, AA at SNP locus 2, AA at SNP locus 3, AA at SNP locus 4, AA at SNP locus 5, AA at SNP locus 6, and TT at SNP locus 7.

[0049] Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes at SNP loci: GT at SNP loci 1, GA at SNP loci 2, TA at SNP loci 3, GA at SNP loci 4, AA at SNP loci 5, CA at SNP loci 6, and TT at SNP loci 7.

[0050] Individuals with the following genotypes at SNP loci (GG, GG, TT, GG, GG, CC, CC at SNP loci 6 and CC at SNP loci 7) had significantly lower starting birth weight than individuals with the following genotypes at SNP loci (GG, GG, TT, GG, AA, CC at SNP loci 6 and TC at SNP loci 7).

[0051] Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes at SNP loci: TT at SNP loci 1, AA at SNP loci 2, AA at SNP loci 3, AA at SNP loci 4, AA at SNP loci 5, AA at SNP loci 6, and TT at SNP loci 7.

[0052] Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, AA at SNP loci 5, CC at SNP loci 6, and TT at SNP loci 7.

[0053] Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, AG at SNP loci 5, CC at SNP loci 6, and TC at SNP loci 7.

[0054] Individuals with the following genotypes at SNP locus 1 (GG), SNP locus 2 (GG), SNP locus 3 (TT), SNP locus 4 (GG), SNP locus 5 (AA), SNP locus 6 (CC), and SNP locus 7 (TC) had significantly higher egg production at 300 days than individuals with the following genotypes at SNP locus 1 (GT), SNP locus 2 (GA), SNP locus 3 (TA), SNP locus 4 (GA), SNP locus 5 (AA), SNP locus 6 (CA), and SNP locus 7 (TT).

[0055] And, the detection reagent for the haplotype molecular marker.

[0056] Preferably, the detection reagent is a primer.

[0057] More preferably, the nucleotide sequences of the primers shown are as shown in SEQ ID NO:1 to 2.

[0058] Further protection is sought for the use of the haplotype molecular marker or the detection reagent in the preparation of a kit for evaluating the egg production performance of Leizhou Black Duck and / or a method for evaluating the egg production performance of Leizhou Black Duck.

[0059] And, a kit for evaluating the egg production performance of Leizhou black duck, containing any of the reagents or the detection reagents.

[0060] Preferably, the reagent or the detection reagent is a primer.

[0061] More preferably, the nucleotide sequences of the primers shown are as shown in SEQ ID NO:1 to 2.

[0062] Preferably, it also contains PCR reagents.

[0063] More preferably, the PCR reagent is Green Taq Mix and / or ddH2O.

[0064] The PCR reaction system of the kit (20 μL) contains: 1 μL DNA template, 10 μL Green Taq Mix, 0.5 μL each of upstream and downstream primers (SEQ ID NO: 1 and 2), and 8 μL ddH2O.

[0065] The PCR reaction program for the kit is as follows: 95℃ pre-denaturation for 3 min; 95℃ denaturation for 15 s, 50℃ annealing for 15 s, 72℃ extension for 50 s, 35 cycles; 72℃ extension for 5 min.

[0066] And a method for evaluating the egg production performance of Leizhou black ducks, using any of the reagents described to detect the genotype of the locus, or to detect the genotype of the haplotype molecular marker.

[0067] As a specific embodiment of the present invention, the primers shown in SEQ ID NO:1 and 2 were used to perform PCR detection on the sample, followed by sequencing, and the results were compared with the ZJU 1.0 version genome:

[0068] PCR reaction system 20 μL: DNA template 1 μL, Green Taq Mix 10 μL, forward and reverse primers (SEQ ID NO: 1 and 2) 0.5 μL each, ddH2O 8 μL.

[0069] PCR reaction program: 95℃ pre-denaturation for 3 min; 95℃ denaturation for 15 s, 50℃ annealing for 15 s, 72℃ extension for 50 s, 35 cycles; 72℃ extension for 5 min.

[0070] SNP locus 1 is located at NC_051796.1:537426, which is nucleotide 537426 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: GG, GT, and TT.

[0071] SNP locus 2 is located at NC_051796.1:537384, which is the 537384th nucleotide on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0072] SNP locus 3 is located at NC_051796.1:537333, which is nucleotide 537333 on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: TT, TA, and AA.

[0073] SNP locus 4 is located at NC_051796.1:537284, which is the 537284th nucleotide on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0074] SNP locus 5 is located at NC_051796.1:537277, which is nucleotide 537277 on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0075] SNP locus 6 is located at NC_051796.1:537187, which is nucleotide 537187 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: CC, CA, and AA.

[0076] SNP locus 7 is located at NC_051796.1:537058, which is nucleotide 537058 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: CC, CT, and TT.

[0077] The egg production performance refers to the age at first laying or the weight at first laying.

[0078] Individuals with the TT genotype at SNP locus 1 had a significantly higher age at onset than individuals with the GT genotype.

[0079] Individuals with the AA genotype at SNP locus 2 had a significantly higher age at onset than individuals with the GA genotype.

[0080] Individuals with the AA genotype at SNP locus 3 had a significantly higher age at onset than individuals with the TA genotype.

[0081] Individuals with the AA genotype at SNP locus 4 had a significantly higher age at onset than individuals with the GA genotype.

[0082] Individuals with the GG genotype at SNP locus 5 had significantly lower birth weights at birth than individuals with the AA genotype.

[0083] Individuals with the GG genotype at SNP locus 5 had significantly lower birth weights at birth than individuals with the GA genotype.

[0084] Individuals with the AA genotype at SNP locus 6 had a significantly higher age at onset than individuals with the CA genotype.

[0085] Individuals with the CC genotype at SNP locus 7 had significantly lower birth weights at birth than individuals with the TT or TC genotypes.

[0086] The age at birth of individuals with the following genotypes were significantly lower than that of individuals with the following genotypes: SNP1 genotype GG, SNP2 genotype GG, SNP3 genotype TT, SNP4 genotype GG, SNP5 genotype AA, SNP6 genotype CC, and SNP7 genotype TC.

[0087] The age at birth of individuals with the following genotypes—GG at SNP locus 1, GG at SNP locus 2, TT at SNP locus 3, GG at SNP locus 4, AA at SNP locus 5, CC at SNP locus 6, and TC at SNP locus 7—was significantly lower than that of individuals with the following genotypes—TT at SNP locus 1, AA at SNP locus 2, AA at SNP locus 3, AA at SNP locus 4, AA at SNP locus 5, AA at SNP locus 6, and TT at SNP locus 7.

[0088] Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes at SNP loci: GT at SNP loci 1, GA at SNP loci 2, TA at SNP loci 3, GA at SNP loci 4, AA at SNP loci 5, CA at SNP loci 6, and TT at SNP loci 7.

[0089] Individuals with the following genotypes at SNP loci (GG, GG, TT, GG, GG, CC, CC at SNP loci 6 and CC at SNP loci 7) had significantly lower starting birth weight than individuals with the following genotypes at SNP loci (GG, GG, TT, GG, AA, CC at SNP loci 6 and TC at SNP loci 7).

[0090] Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes at SNP loci: TT at SNP loci 1, AA at SNP loci 2, AA at SNP loci 3, AA at SNP loci 4, AA at SNP loci 5, AA at SNP loci 6, and TT at SNP loci 7.

[0091] Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, AA at SNP loci 5, CC at SNP loci 6, and TT at SNP loci 7.

[0092] Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, AG at SNP loci 5, CC at SNP loci 6, and TC at SNP loci 7.

[0093] Individuals with the following genotypes at SNP locus 1 (GG), SNP locus 2 (GG), SNP locus 3 (TT), SNP locus 4 (GG), SNP locus 5 (AA), SNP locus 6 (CC), and SNP locus 7 (TC) had significantly higher egg production at 300 days than individuals with the following genotypes at SNP locus 1 (GT), SNP locus 2 (GA), SNP locus 3 (TA), SNP locus 4 (GA), SNP locus 5 (AA), SNP locus 6 (CA), and SNP locus 7 (TT).

[0094] This invention also claims protection for the use of one or more of the described reagents, the haplotype molecular markers, the detection reagents, or the Leizhou Black Duck egg production performance evaluation kits in the auxiliary selection of Leizhou Black Duck egg production performance traits or in the molecular breeding of Leizhou Black Duck egg production performance.

[0095] The above-mentioned significance is defined as P < 0.05, and the highly significant is defined as P < 0.01.

[0096] Compared with the prior art, the present invention has the following beneficial effects:

[0097] This invention targets Leizhou Black Duck and identifies five SNP loci (SNP loci 1, SNP loci 2, SNP loci 3, SNP loci 4, and SNP loci 6) that are significantly associated with the age at first egg production in Leizhou Black Ducks; and two SNP loci (SNP loci 5 and SNP loci 7) that are extremely significantly associated with the body weight at first egg production in Leizhou Black Ducks. Furthermore, a haplotype (H1H4) was discovered that exhibits low age at first egg production, high body weight at first egg production, and high egg production. Therefore, individuals with low age at first egg production, low body weight at first egg production, and high egg production can be screened from the dominant genotypes at these seven SNP loci, thereby improving egg production performance and economic benefits. Attached Figure Description

[0098] Figure 1 The results of PCR amplification of the EI24 gene of Leizhou black duck are shown; A is the PCR amplification result of primer 1; 1-6 are the PCR amplification products of DNA from 6 random blood samples, and M is the marker.

[0099] Figure 2 Sequencing maps of the EI24 gene I5-17 G>T genotypes, 1-3, for individuals with genotypes GG, GT, and TT, respectively.

[0100] Figure 3 The sequencing map of the EI24 gene I5-59 G>A three genotypes is shown. Genotypes 1 to 3 are individuals with genotypes GG, GA and AA, respectively.

[0101] Figure 4 Sequencing maps of the EI24 gene I5-110 T>A three genotypes, 1-3, for individuals with genotypes GG, GA, and AA, respectively.

[0102] Figure 5 The sequencing map of the EI24 gene I5-159 G>A three genotypes is shown. Genotypes 1 to 3 are individuals with genotypes GG, GA and AA, respectively.

[0103] Figure 6 The sequencing map of the EI24 gene I5-166 G>A three genotypes is shown. Individuals with genotypes 1-3 are individuals with genotypes GG, GA and AA, respectively.

[0104] Figure 7 The sequencing map of the EI24 gene I5-256 C>A three genotypes is shown. Individuals with genotypes 1-3 are CC, CA and AA, respectively.

[0105] Figure 8 Sequencing maps of the EI24 gene I5-385 C>T genotypes, 1-3, for individuals with genotypes CC, CT, and TT, respectively.

[0106] Figure 9 The reaction was linked to 7 SNP sites of the EI24 gene. Detailed Implementation

[0107] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. These embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Unless otherwise specified, the experimental methods used in the following embodiments are conventional methods; the materials and reagents used, unless otherwise specified, are commercially available.

[0108] Main reagents and instruments

[0109] Blood DNA extraction kit was purchased from Guangzhou Meiji Biotechnology Co., Ltd.; agarose was purchased from Bogelin Biotechnology Co., Ltd.; Taq Master Mix was purchased from Novizan Biotechnology Co., Ltd.; gel imaging system was purchased from Shanghai Tianneng Technology Co., Ltd.; rapid gradient PCR instrument was purchased from ABI Pharmaceuticals, Inc.

[0110] Statistical analysis

[0111] Results are expressed as mean ± standard error. P < 0.05 indicates a significant difference, and P < 0.01 indicates a highly significant difference.

[0112] Example 1: Design of Amplification Primers

[0113] I. Experimental Samples

[0114] Ninety-two 300-day-old Leizhou black ducks were obtained from an F4 generation breeding flock at a farm in Potou District, Zhanjiang City. Two mL of blood was collected from the jugular vein, collected in heparinized anticoagulant tubes, and stored at -20°C for later use in extracting genomic DNA from the blood.

[0115] II. Experimental Methods

[0116] 1. Whole genome DNA extraction

[0117] Blood DNA was extracted using the MGI DNA Extraction Kit, following the instructions in the kit's manual. DNA concentration and purity were measured using a concentration analyzer and stored at -20°C for later use.

[0118] 2. Construction of DNA Mixture Pools

[0119] Fifty DNA samples were randomly selected and mixed in equal amounts to prepare a DNA pool sample.

[0120] 3. Primer design

[0121] Based on the EI24 genome sequence (ID: ENSAPLG00030007779) provided in the Ensemble database, primers for the EI24 gene were designed using Primer 5.0 software. The primers were synthesized by Sangon Biotech (Shanghai) Co., Ltd.

[0122] Primer pair 1:

[0123] Upstream primer: 5′-GCCTTTGCTGTCGTGATAT-3′ (SEQ ID NO:1),

[0124] Downstream primer: 5′-ATGTTCCCGTCACCTACCT-3′ (SEQ ID NO:2);

[0125] 4. PCR amplification and verification of the target gene

[0126] DNA pool samples were amplified by PCR using primer pair 1.

[0127] The PCR reaction system consisted of 20 μL of the following components: 1 μL DNA template, 10 μL Green Taq Mix, 0.5 μL each of upstream and downstream primers (SEQ ID NO: 1 and 2), and 8 μL ddH2O.

[0128] PCR reaction of primer pair 1: 95℃ pre-denaturation for 3 min; 95℃ denaturation for 15 s, 50℃ annealing for 15 s, 72℃ extension for 50 s, 35 cycles; 72℃ extension for 5 min.

[0129] After verification by 1% agarose gel electrophoresis, the sample was sent to Sangon Biotech (Shanghai) Co., Ltd. for sequencing.

[0130] II. Experimental Results

[0131] The PCR amplification of the Leizhou Black Duck EI24 gene (gene number: ENSAPLG00030007779) product was detected by 1% agarose gel electrophoresis. The results showed that the PCR product had good amplification specificity and clear bands, and could be directly used for sequencing identification. Figure 1 ).

[0132] Example 2: Polymorphism of the EI24 gene in Leizhou black ducks

[0133] I. Experimental Methods

[0134] Using primer pair 1, PCR amplification was performed on individual samples from the Leizhou Black Duck population of Example 1, following the method in Example 1.

[0135] Sequence alignment was performed using SnapGene Viewer software. SNP loci and genotypes were analyzed for each individual. Allele frequencies, genotype frequencies, heterozygosity (He), polymorphism information content (PIC), effective allele count (Ne), and chi-square test values ​​were calculated for each SNP locus. 2 .

[0136] Calculation formulas: Genotype frequency = Number of genotypes / Total number of genotypes × 100%; Gene frequency = Number of genes / Total number of genes × 100%; Ne = 1 / (1-He). Where: i is the i-th allele, j is the j-th allele, and P... i and P j denoted as allele frequency, and n as the number of alleles.

[0137] II. Experimental Results

[0138] Following PCR amplification of the EI24 gene, seven SNP sites were identified in intron 5 using primer 1: I5-17G>T (SNP site 1), I5-59 G>A (SNP site 2), I5-110 T>A (SNP site 3), I5-159 G>A (SNP site 4), I5-166 G>A (SNP site 5), I5-256 C>A (SNP site 6), and I5-385 C>T (SNP site 7). Sequencing results for each genotype of the seven SNPs are shown below. Figures 2 to 8 As shown.

[0139] Specifically, SNP locus 1 is located at NC_051796.1:537426, which is the 537426th nucleotide of chromosome 25 in the ZJU1.0 version of the genome, and it has three genotypes: GG, GT, and TT.

[0140] SNP locus 2 is located at NC_051796.1:537384, which is the 537384th nucleotide on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0141] SNP locus 3 is located at NC_051796.1:537333, which is nucleotide 537333 on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: TT, TA, and AA.

[0142] SNP locus 4 is located at NC_051796.1:537284, which is the 537284th nucleotide on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0143] SNP locus 5 is located at NC_051796.1:537277, which is nucleotide 537277 on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0144] SNP locus 6 is located at NC_051796.1:537187, which is nucleotide 537187 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: CC, CA, and AA.

[0145] SNP locus 7 is located at NC_051796.1:537058, which is nucleotide 537058 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: CC, CT, and TT.

[0146] The population genetic characteristics of the 7 SNP loci are shown in Table 1.

[0147] Table 1. Population genetic characteristics of 7 SNPs in the EI24 gene

[0148]

[0149] Example 3: Correlation analysis of EI24 gene SNPs and egg production performance of Leizhou black ducks

[0150] I. Experimental Methods

[0151] The age at first laying, body weight at first laying, initial egg weight, and 300-day egg production of each sample in Example 1 were measured respectively.

[0152] Age at first egg: The age at which a female hen begins laying her first egg;

[0153] Weight at first egg: The weight of a hen when it begins to lay its first egg;

[0154] Initial egg weight: The weight of the first egg laid by the hen;

[0155] 300-day egg production: The total number of eggs laid by a hen 300 days after she begins laying her first egg.

[0156] One-way ANOVA using SPSS 22.0 software was used to test the significance of differences in egg production traits and the association between genotype and haplotype in Leizhou black ducks.

[0157] II. Experimental Results

[0158] One-way ANOVA using SPSS 22.0 software was used to compare the genotypes of SNPs in the EI24 gene, and the results are shown in Table 2.

[0159] Table 2. Correlation analysis of 7 SNPs of EI24 gene with egg production performance of Leizhou black duck.

[0160]

[0161]

[0162] Note: Results are expressed as mean ± standard error. For the same index of the same genotype in the same column at each locus, completely different lowercase letters indicate significant differences (P<0.05), and completely different uppercase letters indicate extremely significant differences (P<0.01); no letter or the same letter indicates no significant difference (P>0.05).

[0163] At SNP locus 1 (I5-17 G>T), the age at labor onset was significantly higher in the TT genotype than in the GT genotype (P<0.05);

[0164] At SNP loci 2 (I5-59 G>A) and SNP loci 4 (I5-159 G>A), the age at labor onset for AA type was significantly higher than that for GA type (P<0.05).

[0165] At SNP locus 3 (I5-110 T>A), the age at labor onset was significantly higher for the AA type than for the TA type (P<0.05);

[0166] At SNP locus 6 (I5-256 C>A), the age at labor onset was significantly higher in the AA type than in the CA type (P<0.05);

[0167] At SNP locus 5 (I5-166 G>A), the birth weight at the start of labor of the GG type was significantly lower than that of the AA type (P<0.01) and significantly lower than that of the GA type (P<0.05).

[0168] At SNP locus 7 (I5-385 C>T), the birth weight at onset of labor was significantly lower in the CC genotype than in the TT and TC genotypes (P<0.01);

[0169] None of the seven SNPs had a significant effect on initial egg weight or 300-day egg production (P > 0.05).

[0170] The results show that SNP loci 1 (I5-17 G>T), SNP loci 2 (I5-59 G>A), SNP loci 3 (I5-110 T>A), SNP loci 4 (I5-159 G>A), and SNP loci 6 (I5-256 C>A) are all significantly associated with the age at first laying of Leizhou Black Ducks; SNP loci 5 (I5-166 G>A) and SNP loci 7 (I5-385 C>T) are extremely significantly associated with the weight at first laying of Leizhou Black Ducks. This indicates that these 7 SNPs may have important reference value for improving the age at first laying and weight at first laying of Leizhou Black Ducks.

[0171] Example 4: Association Analysis between EI24 Gene Haplotype and Egg Production Performance of Leizhou Black Ducks

[0172] I. Experimental Methods

[0173] Haplotype linkage disequilibrium analysis was performed on the seven SNPs of Example 2 using HaploView 4.2 software. One-way ANOVA was then used to compare the haplotypes of the EI24 gene SNPs using SPSS 22.0 software.

[0174] II. Experimental Results

[0175] The results of haplotype linkage disequilibrium analysis are as follows: Figure 9 As shown in Table 3, the results indicate that all seven loci exhibit strong linkage. These seven loci form a single domain with a total of 10 different haplotypes, of which only seven haplotypes are statistically significant (number of individuals greater than 3). These are:

[0176] H1H1: The genotype of SNP locus 1 is GG, the genotype of SNP locus 2 is GG, the genotype of SNP locus 3 is TT, the genotype of SNP locus 4 is GG, the genotype of SNP locus 5 is AA, the genotype of SNP locus 6 is CC and the genotype of SNP locus 7 is TT.

[0177] H1H2 (genotype GT for SNP locus 1, GA for SNP locus 2, TA for SNP locus 3, GA for SNP locus 4, AA for SNP locus 5, CA for SNP locus 6, and TT for SNP locus 7).

[0178] H1H3 (Gen type of SNP locus 1 is GG, Genotype of SNP locus 2 is GG, Genotype of SNP locus 3 is TT, Genotype of SNP locus 4 is GG, Genotype of SNP locus 5 is AG, Genotype of SNP locus 6 is CC and Genotype of SNP locus 7 is TC).

[0179] H1H4 (Genoids of SNP locus 1 are GG, SNP locus 2 are GG, SNP locus 3 is TT, SNP locus 4 is GG, SNP locus 5 is AA, SNP locus 6 is CC and SNP locus 7 is TC).

[0180] H2H2 (genotype TT at SNP locus 1, AA at SNP locus 2, AA at SNP locus 3, AA at SNP locus 4, AA at SNP locus 5, AA at SNP locus 6, and TT at SNP locus 7).

[0181] H2H3 (genotype GT at SNP locus 1, GA at SNP locus 2, TA at SNP locus 3, GA at SNP locus 4, GA at SNP locus 5, CA at SNP locus 6, and CT at SNP locus 7).

[0182] H3H3 (Gen type of SNP locus 1 is GG, genotype of SNP locus 2 is GG, genotype of SNP locus 3 is TT, genotype of SNP locus 4 is GG, genotype of SNP locus 5 is GG, genotype of SNP locus 6 is CC and genotype of SNP locus 7 is CC).

[0183] Table 3. Haplotype frequencies of EI24 gene

[0184]

[0185]

[0186] One-way ANOVA using SPSS 22.0 software was used to perform multiple comparisons of SNP haplotypes in the EI24 gene. The results are shown in Table 4. The age at first laying of haplotype H1H4 was significantly lower than that of haplotypes H1H1 and H2H2 (P < 0.05); the weight at first laying of haplotype H3H3 was significantly lower than that of haplotypes H1H2, H1H4, and H2H2 (P < 0.05), and extremely significantly lower than that of haplotypes H1H1 and H1H3 (P < 0.01); the 300-day egg production of haplotype H1H4 was significantly higher than that of haplotype H1H2 (P < 0.05). None of the seven haplotypes had a significant effect on the weight at first laying (P > 0.05).

[0187] Table 4. Correlation analysis between EI24 genotype and egg production performance of Leizhou black duck.

[0188]

[0189] Note: All results are expressed as mean ± standard error. Completely different lowercase letters in the same column for the same indicator indicate a significant difference (P < 0.05); completely different uppercase letters indicate an extremely significant difference (P < 0.01); no letter or the same letter indicates no significant difference (P > 0.05).

[0190] Example 5: A kit for evaluating the egg production performance of Leizhou black ducks

[0191] I. Methods

[0192] The samples were subjected to PCR detection using primers shown in SEQ ID NO:1 and 2, followed by sequencing, and then compared with the ZJU 1.0 genome version:

[0193] PCR reaction system 20 μL: DNA template 1 μL, Green Taq Mix 10 μL, forward and reverse primers (SEQ ID NO: 1 and 2) 0.5 μL each, ddH2O 8 μL.

[0194] PCR reaction program: 95℃ pre-denaturation for 3 min; 95℃ denaturation for 15 s, 50℃ annealing for 15 s, 72℃ extension for 50 s, 35 cycles; 72℃ extension for 5 min.

[0195] II. Result Interpretation

[0196] SNP locus 1 is located at NC_051796.1:537426, which is nucleotide 537426 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: GG, GT, and TT.

[0197] SNP locus 2 is located at NC_051796.1:537384, which is the 537384th nucleotide on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0198] SNP locus 3 is located at NC_051796.1:537333, which is nucleotide 537333 on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: TT, TA, and AA.

[0199] SNP locus 4 is located at NC_051796.1:537284, which is the 537284th nucleotide on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0200] SNP locus 5 is located at NC_051796.1:537277, which is nucleotide 537277 on chromosome 25 of the ZJU1.0 version genome. It has three genotypes: GG, GA, and AA.

[0201] SNP locus 6 is located at NC_051796.1:537187, which is nucleotide 537187 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: CC, CA, and AA.

[0202] SNP locus 7 is located at NC_051796.1:537058, which is nucleotide 537058 on chromosome 25 of the ZJU 1.0 version genome. It has three genotypes: CC, CT, and TT.

[0203] The egg production performance refers to the age at first laying or the weight at first laying.

[0204] Individuals with the TT genotype at SNP locus 1 had a significantly higher age at onset than individuals with the GT genotype.

[0205] Individuals with the AA genotype at SNP locus 2 had a significantly higher age at onset than individuals with the GA genotype.

[0206] Individuals with the AA genotype at SNP locus 3 had a significantly higher age at onset than individuals with the TA genotype.

[0207] Individuals with the AA genotype at SNP locus 4 had a significantly higher age at onset than individuals with the GA genotype.

[0208] Individuals with the GG genotype at SNP locus 5 had significantly lower birth weights at birth than individuals with the AA genotype.

[0209] Individuals with the GG genotype at SNP locus 5 had significantly lower birth weights at birth than individuals with the GA genotype.

[0210] Individuals with the AA genotype at SNP locus 6 had a significantly higher age at onset than individuals with the CA genotype.

[0211] Individuals with the CC genotype at SNP locus 7 had significantly lower birth weights at birth than individuals with the TT or TC genotypes.

[0212] The age at birth of individuals with the following genotypes were significantly lower than that of individuals with the following genotypes: SNP1 genotype GG, SNP2 genotype GG, SNP3 genotype TT, SNP4 genotype GG, SNP5 genotype AA, SNP6 genotype CC, and SNP7 genotype TC.

[0213] The age at birth of individuals with the following genotypes—GG at SNP locus 1, GG at SNP locus 2, TT at SNP locus 3, GG at SNP locus 4, AA at SNP locus 5, CC at SNP locus 6, and TC at SNP locus 7—was significantly lower than that of individuals with the following genotypes—TT at SNP locus 1, AA at SNP locus 2, AA at SNP locus 3, AA at SNP locus 4, AA at SNP locus 5, AA at SNP locus 6, and TT at SNP locus 7.

[0214] Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes at SNP loci: GT at SNP loci 1, GA at SNP loci 2, TA at SNP loci 3, GA at SNP loci 4, AA at SNP loci 5, CA at SNP loci 6, and TT at SNP loci 7.

[0215] Individuals with the following genotypes at SNP loci (GG, GG, TT, GG, GG, CC, CC at SNP loci 6 and CC at SNP loci 7) had significantly lower starting birth weight than individuals with the following genotypes at SNP loci (GG, GG, TT, GG, AA, CC at SNP loci 6 and TC at SNP loci 7).

[0216] Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes at SNP loci: TT at SNP loci 1, AA at SNP loci 2, AA at SNP loci 3, AA at SNP loci 4, AA at SNP loci 5, AA at SNP loci 6, and TT at SNP loci 7.

[0217] Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, AA at SNP loci 5, CC at SNP loci 6, and TT at SNP loci 7.

[0218] Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, AG at SNP loci 5, CC at SNP loci 6, and TC at SNP loci 7.

[0219] Individuals with the following genotypes at SNP locus 1 (GG), SNP locus 2 (GG), SNP locus 3 (TT), SNP locus 4 (GG), SNP locus 5 (AA), SNP locus 6 (CC), and SNP locus 7 (TC) had significantly higher egg production at 300 days than individuals with the following genotypes at SNP locus 1 (GT), SNP locus 2 (GA), SNP locus 3 (TA), SNP locus 4 (GA), SNP locus 5 (AA), SNP locus 6 (CA), and SNP locus 7 (TT).

[0220] Example 6: A kit for evaluating the egg production performance of Leizhou black ducks

[0221] I. Composition

[0222] Nucleotide sequences are shown in SEQ ID NO:1 to 2. Primers, Green Taq Mix, and ddH2O are also used.

[0223] II. Instructions for Use

[0224] Same as "I. Method" and "II. Result Interpretation" in Example 5.

[0225] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and are not intended to limit the scope of protection of the present invention. For those skilled in the art, other variations or modifications can be made based on the above description and ideas, and it is neither necessary nor possible to exhaustively describe all implementation methods here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included within the scope of protection of the claims of the present invention.

Claims

1. Application of a primer for detecting the genotype of a SNP site associated with the laying trait of Leizhou black duck in evaluating the laying performance of Leizhou black duck, characterized in that the primer is used for detecting SNP site 1, SNP site 2, SNP site 3, SNP site 4, SNP site 5, SNP site 6 and SNP site 7: SNP site 1 is located at NC_051796.1:537426, G is mutated to T, i.e. the 537426th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GT and TT; SNP site 2 is located at NC_051796.1:537384, G is mutated to A, i.e. the 537384th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 3 is located at NC_051796.1:537333, T is mutated to A, i.e. the 537333th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of TT, TA and AA; SNP site 4 is located at NC_051796.1:537284, G is mutated to A, i.e. the 537284th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 5 is located at NC_051796.1:537277, G is mutated to A, i.e. the 537277th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 6 is located at NC_051796.1:537187, C is mutated to A, i.e. the 537187th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CA and AA; SNP site 7 is located at NC_051796.1:537058, C is mutated to T, i.e. the 537058th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CT and TT; the laying performance is the age at first laying or the body weight at first laying; the age at first laying of the individual with TT genotype of SNP site 1 is significantly higher than that of the individual with GT genotype; the age at first laying of the individual with AA genotype of SNP site 2 is significantly higher than that of the individual with GA genotype; the age at first laying of the individual with AA genotype of SNP site 3 is significantly higher than that of the individual with TA genotype; the age at first laying of the individual with AA genotype of SNP site 4 is significantly higher than that of the individual with GA genotype; the body weight at first laying of the individual with GG genotype of SNP site 5 is extremely significantly lower than that of the individual with AA genotype; the body weight at first laying of the individual with GG genotype of SNP site 5 is significantly lower than that of the individual with GA genotype; the age at first laying of the individual with AA genotype of SNP site 6 is significantly higher than that of the individual with CA genotype; the body weight at first laying of the individual with CC genotype of SNP site 7 is extremely significantly lower than that of the individual with TT genotype; the body weight at first laying of the individual with CC genotype of SNP site 7 is extremely significantly lower than that of the individual with TC genotype. ​ 2. Application of a primer for detecting the genotype of a SNP site related to the laying performance of Leizhou black duck in the preparation of a kit for evaluating the laying performance of Leizhou black duck, characterized in that the primer is used to detect SNP site 1, SNP site 2, SNP site 3, SNP site 4, SNP site 5, SNP site 6 and SNP site 7: SNP site 1 is located at NC_051796.1:537426, G is mutated to T, i.e. the 537426th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GT and TT; SNP site 2 is located at NC_051796.1:537384, G is mutated to A, i.e. the 537384th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 3 is located at NC_051796.1:537333, T is mutated to A, i.e. the 537333th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of TT, TA and AA; SNP site 4 is located at NC_051796.1:537284, G is mutated to A, i.e. the 537284th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 5 is located at NC_051796.1:537277, G is mutated to A, i.e. the 537277th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 6 is located at NC_051796.1:537187, C is mutated to A, i.e. the 537187th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CA and AA; SNP site 7 is located at NC_051796.1:537058, C is mutated to T, i.e. the 537058th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CT and TT; the laying performance is the age at first laying or the body weight at first laying; the age at first laying of the individual with TT genotype of SNP site 1 is significantly higher than that of the individual with GT genotype; the age at first laying of the individual with AA genotype of SNP site 2 is significantly higher than that of the individual with GA genotype; the age at first laying of the individual with AA genotype of SNP site 3 is significantly higher than that of the individual with TA genotype; the age at first laying of the individual with AA genotype of SNP site 4 is significantly higher than that of the individual with GA genotype; the body weight at first laying of the individual with GG genotype of SNP site 5 is extremely significantly lower than that of the individual with AA genotype; the body weight at first laying of the individual with GG genotype of SNP site 5 is significantly lower than that of the individual with GA genotype; the age at first laying of the individual with AA genotype of SNP site 6 is significantly higher than that of the individual with CA genotype; the body weight at first laying of the individual with CC genotype of SNP site 7 is extremely significantly lower than that of the individual with TT genotype; ​ The CC genotype individual of SNP site 7 is extremely significantly lower than the TC genotype individual in the first production weight.

3. The application of a primer for detecting the genotype of a SNP site related to the laying performance of Leizhou black duck in establishing an evaluation method for the laying performance of Leizhou black duck, characterized in that, The primer is used for detecting SNP site 1, SNP site 2, SNP site 3, SNP site 4, SNP site 5, SNP site 6 and SNP site 7: SNP site 1 is located at NC_051796.1:537426, G is mutated to T, i.e. the 537426th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GT and TT; SNP site 2 is located at NC_051796.1:537384, G is mutated to A, i.e. the 537384th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 3 is located at NC_051796.1:537333, T is mutated to A, i.e. the 537333th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of TT, TA and AA; SNP site 4 is located at NC_051796.1:537284, G is mutated to A, i.e. the 537284th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 5 is located at NC_051796.1:537277, G is mutated to A, i.e. the 537277th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 6 is located at NC_051796.1:537187, C is mutated to A, i.e. the 537187th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CA and AA; SNP site 7 is located at NC_051796.1:537058, C is mutated to T, i.e. the 537058th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CT and TT; The laying performance is the first production age or the first production weight; The first production age of the TT genotype individual of SNP site 1 is significantly higher than that of the GT genotype individual; The first production age of the AA genotype individual of SNP site 2 is significantly higher than that of the GA genotype individual; The first production age of the AA genotype individual of SNP site 3 is significantly higher than that of the TA genotype individual; The first production age of the AA genotype individual of SNP site 4 is significantly higher than that of the GA genotype individual; The first production weight of the GG genotype individual of SNP site 5 is extremely significantly lower than that of the AA genotype individual; The first production weight of the GG genotype individual of SNP site 5 is significantly lower than that of the GA genotype individual; The first production age of the AA genotype individual of SNP site 6 is significantly higher than that of the CA genotype individual; The CC genotype individual of SNP site 7 is extremely significantly lower than the TT genotype individual in the body weight of the first egg; The CC genotype individual of SNP site 7 is extremely significantly lower than the TC genotype individual in the body weight of the first egg.

4. Application of a primer for detecting the genotype of a SNP site related to the egg laying traits of Leizhou black duck in marker assisted selection of egg laying performance related traits of Leizhou black duck, characterized in that, The primer is used to detect SNP site 1, SNP site 2, SNP site 3, SNP site 4, SNP site 5, SNP site 6 and SNP site 7: SNP site 1 is located at NC_051796.1:537426, G is mutated to T, i.e. the 537426th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GT and TT; SNP site 2 is located at NC_051796.1:537384, G is mutated to A, i.e. the 537384th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 3 is located at NC_051796.1:537333, T is mutated to A, i.e. the 537333th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of TT, TA and AA; SNP site 4 is located at NC_051796.1:537284, G is mutated to A, i.e. the 537284th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 5 is located at NC_051796.1:537277, G is mutated to A, i.e. the 537277th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 6 is located at NC_051796.1:537187, C is mutated to A, i.e. the 537187th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CA and AA; SNP site 7 is located at NC_051796.1:537058, C is mutated to T, i.e. the 537058th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CT and TT; The egg laying performance is the age of the first egg or the body weight of the first egg; The TT genotype individual of SNP site 1 is significantly higher than the GT genotype individual in the age of the first egg; The AA genotype individual of SNP site 2 is significantly higher than the GA genotype individual in the age of the first egg; The AA genotype individual of SNP site 3 is significantly higher than the TA genotype individual in the age of the first egg; The AA genotype individual of SNP site 4 is significantly higher than the GA genotype individual in the age of the first egg; The GG genotype individual of SNP site 5 is extremely significantly lower than the AA genotype individual in the body weight of the first egg; The GG genotype individual of SNP site 5 is significantly lower than the GA genotype individual in the body weight of the first egg; The AA genotype individual of SNP site 6 has a significantly higher age of first laying than the CA genotype individual; The CC genotype individual of SNP site 7 has a significantly lower body weight at first laying than the TT genotype individual; The CC genotype individual of SNP site 7 has a significantly lower body weight at first laying than the TC genotype individual.

5. Application of a primer for detecting the genotype of a SNP site related to the egg laying trait of Leizhou black duck in molecular breeding of the egg laying performance of Leizhou black duck, characterized in that, The primer is used to detect SNP site 1, SNP site 2, SNP site 3, SNP site 4, SNP site 5, SNP site 6 and SNP site 7: SNP site 1 is located at NC_051796.1:537426, G is mutated to T, i.e. the 537426th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GT and TT; SNP site 2 is located at NC_051796.1:537384, G is mutated to A, i.e. the 537384th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 3 is located at NC_051796.1:537333, T is mutated to A, i.e. the 537333th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of TT, TA and AA; SNP site 4 is located at NC_051796.1:537284, G is mutated to A, i.e. the 537284th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 5 is located at NC_051796.1:537277, G is mutated to A, i.e. the 537277th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 6 is located at NC_051796.1:537187, C is mutated to A, i.e. the 537187th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CA and AA; SNP site 7 is located at NC_051796.1:537058, C is mutated to T, i.e. the 537058th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CT and TT; The egg laying performance is age of first laying or body weight at first laying; The TT genotype individual of SNP site 1 has a significantly higher age of first laying than the GT genotype individual; The AA genotype individual of SNP site 2 has a significantly higher age of first laying than the GA genotype individual; The AA genotype individual of SNP site 3 has a significantly higher age of first laying than the TA genotype individual; The AA genotype individual of SNP site 4 has a significantly higher age of first laying than the GA genotype individual; The GG genotype individual of SNP site 5 has a significantly lower body weight at first laying than the AA genotype individual; The GG genotype individual of SNP site 5 has a significantly lower body weight than the GA genotype individual; The AA genotype individual of SNP site 6 has a significantly higher age of first production than the CA genotype individual; The CC genotype individual of SNP site 7 has a significantly lower body weight than the TT genotype individual; The CC genotype individual of SNP site 7 has a significantly lower body weight than the TC genotype individual.

6. The application of any one of claims 1 or 5, wherein the nucleotide sequence of the primer is shown in SEQ ID NO: 1 to 2.

7. The application of a primer for detecting the genotype of a haplotype molecular marker related to the egg laying trait of Leizhou black duck in evaluating the egg laying performance of Leizhou black duck, characterized in that the haplotype molecular marker is composed of seven SNP sites: SNP site 1, SNP site 2, SNP site 3, SNP site 4, SNP site 5, SNP site 6 and SNP site 7: SNP site 1 is located at NC_051796.1:537426, G is mutated to T, i.e. the 537426th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GT and TT; SNP site 2 is located at NC_051796.1:537384, G is mutated to A, i.e. the 537384th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 3 is located at NC_051796.1:537333, T is mutated to A, i.e. the 537333th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of TT, TA and AA; SNP site 4 is located at NC_051796.1:537284, G is mutated to A, i.e. the 537284th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 5 is located at NC_051796.1:537277, G is mutated to A, i.e. the 537277th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; SNP site 6 is located at NC_051796.1:537187, C is mutated to A, i.e. the 537187th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CA and AA; SNP site 7 is located at NC_051796.1:537058, C is mutated to T, i.e. the 537058th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CT and TT. ​ The age at birth of individuals with the following genotypes were significantly lower than that of individuals with the following genotypes: SNP1 genotype GG, SNP2 genotype GG, SNP3 genotype TT, SNP4 genotype GG, SNP5 genotype AA, SNP6 genotype CC, and SNP7 genotype TC. The age at birth of individuals with the following genotypes—GG at SNP locus 1, GG at SNP locus 2, TT at SNP locus 3, GG at SNP locus 4, AA at SNP locus 5, CC at SNP locus 6, and TC at SNP locus 7—was significantly lower than that of individuals with the following genotypes—TT at SNP locus 1, AA at SNP locus 2, AA at SNP locus 3, AA at SNP locus 4, AA at SNP locus 5, AA at SNP locus 6, and TT at SNP locus 7. Individuals with the following genotypes at SNP loci: GG at SNP loci 1, GG at SNP loci 2, TT at SNP loci 3, GG at SNP loci 4, GG at SNP loci 5, CC at SNP loci 6, and CC at SNP loci 7 had significantly lower starting birth weights than individuals with the following genotypes at SNP loci: GT at SNP loci 1, GA at SNP loci 2, TA at SNP loci 3, GA at SNP loci 4, AA at SNP loci 5, CA at SNP loci 6, and TT at SNP loci 7. Individuals with the following genotypes at SNP loci (GG, GG, TT, GG, GG, CC, CC at SNP loci 6 and CC at SNP loci 7) had significantly lower starting birth weight than individuals with the following genotypes at SNP loci (GG, GG, TT, GG, AA, CC at SNP loci 6 and TC at SNP loci 7). The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 has a significantly lower first-litter weight than the individual with the genotype of TT at the SNP site 1, the genotype of AA at the SNP site 2, the genotype of AA at the SNP site 3, the genotype of AA at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of AA at the SNP site 6 and the genotype of TT at the SNP site 7, The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 has a significantly lower first-litter weight than the individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of TT at the SNP site 7, The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 has a significantly lower first-litter weight than the individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of AG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of TC at the SNP site 7; The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of TC at the SNP site 7 has a significantly higher 300d egg production than the individual with the genotype of GT at the SNP site 1, the genotype of GA at the SNP site 2, the genotype of TA at the SNP site 3, the genotype of GA at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CA at the SNP site 6 and the genotype of TT at the SNP site 7.

8. The application of a primer for detecting the genotype of a haplotype molecular marker related to the egg-laying trait of Leizhou black duck in establishing an evaluation method for the egg-laying performance of Leizhou black duck, characterized in that, The haplotype molecular marker is composed of 7 SNP loci: SNP locus 1, SNP locus 2, SNP locus 3, SNP locus 4, SNP locus 5, SNP locus 6 and SNP locus 7: The SNP locus 1 is located at NC_051796.1:537426, G is mutated into T, that is, the 537426th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GT and TT; The SNP locus 2 is located at NC_051796.1:537384, G is mutated into A, that is, the 537384th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; The SNP locus 3 is located at NC_051796.1:537333, T is mutated into A, that is, the 537333th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of TT, TA and AA; The SNP locus 4 is located at NC_051796.1:537284, G is mutated into A, that is, the 537284th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; The SNP locus 5 is located at NC_051796.1:537277, G is mutated into A, that is, the 537277th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; The SNP locus 6 is located at NC_051796.1:537187, C is mutated into A, that is, the 537187th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CA and AA; The SNP locus 7 is located at NC_051796.1:537058, C is mutated into T, that is, the 537058th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CT and TT; The first to seventh SNP loci are respectively SNP locus 1, SNP locus 2, SNP locus 3, SNP locus 4, SNP locus 5, SNP locus 6 and SNP locus 7; The first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG, the sixth SNP site is CC, and the seventh SNP site is CC haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG, the sixth SNP site is CC, and the seventh SNP site is CC haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG, the sixth SNP site is CC, and the seventh SNP site is CC haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG, the sixth SNP site is CC, and the seventh SNP site is CC haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG, the sixth SNP site is CC, and the seventh SNP site is CC haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG, the sixth SNP site is CC, and the seventh SNP site is CC haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG, the sixth SNP site is CC, and the seventh SNP site is CC haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG, the sixth SNP site is CC, and the seventh SNP site is CC haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG, the sixth SNP site is CC, and the seventh SNP site is CC haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG, the sixth SNP site is CC, and the seventh SNP site is CC haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG, the sixth SNP site is CC, and the seventh SNP site is CC haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG, the sixth SNP site is CC, and the seventh SNP site is CC haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is AA, the sixth SNP site is CC, and the seventh SNP site is TC haplotype, the first SNP site is TT, the second SNP site is AA, the third SNP site is AA, the fourth SNP site is AA, the fifth SNP site is AA, the sixth SNP site is AA, and the seventh SNP site is TT haplotype, the first SNP site is GG, the second SNP site is GG, the third SNP site is TT, the fourth SNP site is GG, the fifth SNP site is GG ​ ​ ​ The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 has a significantly lower 300d egg production than the individual with the genotype of GT at the SNP site 1, the genotype of GA at the SNP site 2, the genotype of TA at the SNP site 3, the genotype of GA at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CA at the SNP site 6 and the genotype of TT at the SNP site 7. The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 has a significantly lower 300d egg production than the individual with the genotype of GT at the SNP site 1, the genotype of GA at the SNP site 2, the genotype of TA at the SNP site 3, the genotype of GA at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CA at the SNP site 6 and the genotype of TT at the SNP site 7. The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of TC at the SNP site 7 has a significantly higher 300d egg production than the individual with the genotype of GT at the SNP site 1, the genotype of GA at the SNP site 2, the genotype of TA at the SNP site 3, the genotype of GA at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CA at the SNP site 6 and the genotype of TT at the SNP site 7.

9. The application of a primer for detecting the genotype of a haplotype molecular marker related to the egg laying traits of Leizhou black ducks in marker-assisted selection of egg laying performance related traits of Leizhou black ducks, characterized in that The haplotype molecular marker comprises seven SNP sites: SNP site 1, SNP site 2, SNP site 3, SNP site 4, SNP site 5, SNP site 6 and SNP site 7: The SNP site 1 is located at NC_051796.1:537426, G is mutated to T, i.e. the 537426th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GT and TT; The SNP site 2 is located at NC_051796.1:537384, G is mutated to A, i.e. the 537384th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; The SNP site 3 is located at NC_051796.1:537383, G is mutated to T, i.e. the 537383th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of TT, TA and TT; The SNP site 4 is located at NC_051796.1:537382, G is mutated to A, i.e. the 537382th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and GA; The SNP site 5 is located at NC_051796.1:537381, G is mutated to A, i.e. the 537381th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of AA, AG and AA; The SNP site 6 is located at NC_051796.1:537380, G is mutated to C, i.e. the 537380th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of CC, CA and CC; The SNP site 7 is located at NC_051796.1:537379, G is mutated to T, i.e. the 537379th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of TT, TC and TT. The SNP site 3 is located at NC_051796.1:537333, T is mutated into A, that is, the 537333th nucleotide of the 25th chromosome of the ZJU1.0 version genome, and there are three genotypes of TT, TA and AA; The SNP site 4 is located at NC_051796.1:537284, G is mutated into A, that is, the 537284th nucleotide of the 25th chromosome of the ZJU1.0 version genome, and there are three genotypes of GG, GA and AA; The SNP site 5 is located at NC_051796.1:537277, G is mutated into A, that is, the 537277th nucleotide of the 25th chromosome of the ZJU1.0 version genome, and there are three genotypes of GG, GA and AA; The SNP site 6 is located at NC_051796.1:537187, C is mutated into A, that is, the 537187th nucleotide of the 25th chromosome of the ZJU1.0 version genome, and there are three genotypes of CC, CA and AA; The SNP site 7 is located at NC_051796.1:537058, C is mutated into T, that is, the 537058th nucleotide of the 25th chromosome of the ZJU1.0 version genome, and there are three genotypes of CC, CT and TT; The calving age of the individual with the genotype of GG of the SNP site 1, the genotype of GG of the SNP site 2, the genotype of TT of the SNP site 3, the genotype of GG of the SNP site 4, the genotype of AA of the SNP site 5, the genotype of CC of the SNP site 6 and the genotype of TC of the SNP site 7 is significantly lower than that of the individual with the genotype of GG of the SNP site 1, the genotype of GG of the SNP site 2, the genotype of TT of the SNP site 3, the genotype of GG of the SNP site 4, the genotype of AA of the SNP site 5, the genotype of CC of the SNP site 6 and the genotype of TT of the SNP site 7; The calving age of the individual with the genotype of GG of the SNP site 1, the genotype of GG of the SNP site 2, the genotype of TT of the SNP site 3, the genotype of GG of the SNP site 4, the genotype of AA of the SNP site 5, the genotype of CC of the SNP site 6 and the genotype of TC of the SNP site 7 is significantly lower than that of the individual with the genotype of TT of the SNP site 1, the genotype of AA of the SNP site 2, the genotype of AA of the SNP site 3, the genotype of AA of the SNP site 4, the genotype of AA of the SNP site 5, the genotype of AA of the SNP site 6 and the genotype of TT of the SNP site 7; The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 has a significantly lower birth weight than the individual with the genotype of GT at the SNP site 1, the genotype of GA at the SNP site 2, the genotype of TA at the SNP site 3, the genotype of GA at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CA at the SNP site 6 and the genotype of TT at the SNP site 7, The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 has a significantly lower birth weight than the individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of TC at the SNP site 7, The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 has a significantly lower birth weight than the individual with the genotype of TT at the SNP site 1, the genotype of AA at the SNP site 2, the genotype of AA at the SNP site 3, the genotype of AA at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of AA at the SNP site 6 and the genotype of TT at the SNP site 7, The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 has a significantly lower birth weight than the individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of TT at the SNP site 7, The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 has a significantly lower 300d egg production than the individual with the genotype of GT at the SNP site 1, the genotype of GA at the SNP site 2, the genotype of TA at the SNP site 3, the genotype of GA at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CA at the SNP site 6 and the genotype of TT at the SNP site 7. The individual with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of TC at the SNP site 7 has a significantly higher 300d egg production than the individual with the genotype of GT at the SNP site 1, the genotype of GA at the SNP site 2, the genotype of TA at the SNP site 3, the genotype of GA at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CA at the SNP site 6 and the genotype of TT at the SNP site 7.

10. The application of a primer for detecting the genotype of a haplotype molecular marker related to the egg laying trait of Leizhou black duck in the molecular breeding of the egg laying performance of Leizhou black duck, characterized in that the haplotype molecular marker is composed of seven SNP sites: SNP site 1, SNP site 2, SNP site 3, SNP site 4, SNP site 5, SNP site 6 and SNP site 7: The SNP site 1 is located at NC_051796.1:537426, G is mutated to T, i.e. the 537426th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GT and TT; The SNP site 2 is located at NC_051796.1:537384, G is mutated to A, i.e. the 537384th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; The SNP site 3 is located at NC_051796.1:537333, T is mutated to A, i.e. the 537333th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of TT, TA and AA; The SNP site 4 is located at NC_051796.1:537284, G is mutated to A, i.e. the 537284th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; The SNP site 5 is located at NC_051796.1:537277, G is mutated to A, i.e. the 537277th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; The SNP site 6 is located at NC_051796.1:537277, G is mutated to A, i.e. the 537277th nucleotide of the 25th chromosome of the ZJU1.0 version genome, which has three genotypes of GG, GA and AA; The SNP site 6 is located at NC_051796.1:537187, C is mutated into A, that is, the 537187th nucleotide of the 25th chromosome of the ZJU1.0 version genome, and there are three genotypes of CC, CA and AA; The SNP site 7 is located at NC_051796.1:537058, C is mutated into T, that is, the 537058th nucleotide of the 25th chromosome of the ZJU1.0 version genome, and there are three genotypes of CC, CT and TT; The first to seventh SNP sites of the individual in the haplotype of GG, GG, TT, GG, AA, CC and TC have a significantly lower age at first calving than the individual in the haplotype of GG, GG, TT, GG, AA, CC and TT; The first to seventh SNP sites of the individual in the haplotype of GG, GG, TT, GG, AA, CC and TC have a significantly lower age at first calving than the individual in the haplotype of GG, GG, TT, GG, AA, CC and TT; The first to seventh SNP sites of the individual in the haplotype of GG, GG, TT, GG, AA, CC and TC have a significantly lower age at first calving than the individual in the haplotype of GG, GG, TT, GG, AA, CC and TT; individuals with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 have a significantly lower birth weight than individuals with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of TC at the SNP site 7, individuals with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 have a significantly lower birth weight than individuals with the genotype of TT at the SNP site 1, the genotype of AA at the SNP site 2, the genotype of AA at the SNP site 3, the genotype of AA at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of AA at the SNP site 6 and the genotype of TT at the SNP site 7, individuals with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 have a significantly lower birth weight than individuals with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of TT at the SNP site 7, individuals with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of GG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of CC at the SNP site 7 have a significantly lower birth weight than individuals with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of AG at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of TC at the SNP site 7; The individual 300d with the genotype of GG at the SNP site 1, the genotype of GG at the SNP site 2, the genotype of TT at the SNP site 3, the genotype of GG at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CC at the SNP site 6 and the genotype of TC at the SNP site 7 has a significantly higher egg production than the individual with the genotype of GT at the SNP site 1, the genotype of GA at the SNP site 2, the genotype of TA at the SNP site 3, the genotype of GA at the SNP site 4, the genotype of AA at the SNP site 5, the genotype of CA at the SNP site 6 and the genotype of TT at the SNP site 7.

11. The use according to any one of claims 7 to 10, wherein the nucleotide sequence of the primer is as shown in SEQ ID NO: 1 to 2.

12. Application of a Leizhou black duck egg laying performance evaluation kit in Leizhou black duck egg laying performance related trait marker assisted selection or Leizhou black duck egg laying performance molecular breeding, characterized in that, The kit comprises the primer according to any one of claims 1 to 11.

13. An evaluation method of laying performance of Leizhou black duck, characterized in that, The genotype of the SNP site is detected by the primer according to any one of claims 1 to 5, or the genotype of the haplotype molecular marker is detected by the primer according to any one of claims 7 to 10.

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