A SNP molecular marker, detection primer, kit and breeding method related to chicken growth, body size and carcass traits

Abstract

The present invention relates to a SNP molecular marker, detection primer, kit and breeding method related to chicken growth, body size and carcass traits. The present invention has found through research that a SNP site rs53587188 on the first intron of the chicken FGF2 gene has an A>G mutation. Through association analysis, it is found that the SNP site is significantly correlated with chicken growth, body size and carcass traits, and can be used as a molecular marker for genetic improvement of chicken varieties. Detecting the genotype of the above-mentioned SNP molecular marker can effectively predict the weight of the chicken during the breeding period, thereby shortening the breeding time and accelerating the breeding process. The present invention also provides primers for detecting the genotype of the SNP molecular marker, a kit and a breeding method for improving the growth traits and / or carcass traits and / or body size traits of chickens, which can be used for auxiliary selection and molecular breeding of chickens, and play an important role in improving the growth traits and / or carcass traits and / or body size traits of chickens.

Description

Technical Field

[0001] The invention relates to a SNP molecular marker, a detection primer, a kit and a breeding method related to chicken growth, body size and carcass traits, and belongs to the technical field of biological breeding. Background Art

[0002] Single nucleotide polymorphism (SNP) refers to DNA sequence polymorphism caused by the variation of a single nucleotide at the genome level. Studies have shown that the correlation analysis between SNP diversity and economic traits can provide auxiliary marker selection for poultry molecular breeding. Therefore, the association analysis between SNP diversity and economic traits has always been a hot topic in livestock and poultry genetics research.

[0003] Chicken is an important economic poultry and also an important model organism in scientific research. Growth traits are the main indicators for evaluating chicken production performance, while body size traits and carcass traits can reflect the growth rate and meat production performance of chickens. These three traits are very important economic traits. Therefore, studying the growth traits, body size traits and carcass traits of chickens has important economic value. How to improve the economic traits of local livestock and poultry breeds without changing the germplasm characteristics and maintain the sustainable development of local livestock and poultry is an urgent problem to be solved. In the genetic breeding of livestock and poultry, the application of modern breeding technology with molecular markers is an effective method to accelerate the selection of fine breeds and improve the genetic quality of populations, thereby increasing the production performance of livestock and poultry. Therefore, it is necessary to develop candidate genes related to chicken growth traits, find new molecular markers, and use molecular biological methods to accelerate the process of genetic improvement, thereby shortening the breeding time and speeding up the breeding process. Summary of the invention

[0004] To solve the above problems, the first purpose of the present invention is to provide a SNP molecular marker related to chicken growth, body size and carcass traits. After analysis and verification, the SNP site is significantly correlated with chicken growth traits, body size traits and carcass traits. It can be used as a molecular marker for genetic improvement of chicken breeds and used for auxiliary breeding and molecular breeding of chickens. It is of great significance to improve the growth traits and / or carcass traits and / or body size traits of chickens.

[0005] The second object of the present invention is to provide the application of the above-mentioned SNP molecular marker in the improvement breeding of chicken growth traits and / or carcass traits and / or body size traits, so as to solve the above-mentioned problems.

[0006] The third object of the present invention is to provide a detection primer for detecting the genotype of the above-mentioned SNP molecular marker to solve the above-mentioned problem.

[0007] The fourth object of the present invention is to provide a kit for detecting the genotype of the above-mentioned SNP molecular marker to solve the above-mentioned problem.

[0008] The fifth object of the present invention is to provide the use of the above-mentioned detection primers or detection kit in the improvement breeding of chicken growth traits and / or carcass traits and / or body size traits to solve the above-mentioned problems.

[0009] The sixth object of the present invention is to provide a breeding method for improving chicken growth traits and / or carcass traits and / or body size traits to solve the above problems.

[0010] In order to achieve the above object, a technical solution of SNP molecular markers related to chicken growth, body size and carcass traits in the present invention is:

[0011] A SNP molecular marker related to chicken growth, body size and carcass traits, wherein the nucleotide sequence of the SNP molecular marker is shown in SEQ ID NO.1, and the 168th base from the 5' end is A or G.

[0012] The beneficial effect of the above technical solution is that: the present invention first discovered a SNP site rs53587188 on the first intron of the chicken FGF2 gene, which has an A>G mutation. This SNP molecular marker has not been reported and is a newly discovered SNP molecular marker.

[0013] In order to achieve the above object, the technical scheme of the application of SNP molecular markers in the improvement and breeding of chicken growth traits and / or carcass traits and / or body size traits in the present invention is:

[0014] The invention discloses an application of a SNP molecular marker in breeding for improving growth traits and / or carcass traits and / or body size traits of chickens.

[0015] The beneficial effect of the above technical solution is that: after analysis and verification, the SNP site is significantly correlated with the growth traits, body size traits and carcass traits of chickens, and can be used as a molecular marker for the genetic improvement of chicken breeds, for auxiliary breeding and molecular breeding of chickens, which is beneficial to the genetic improvement of chicken populations with excellent traits, and is of great significance to improving the growth traits and / or carcass traits and / or body size traits of chickens.

[0016] Specifically, the invention is applied in the selection and breeding of chicken weight, shank length, shank circumference, chest width, chest angle, sternum length, body oblique length, eviscerated, half eviscerated, head weight, claw weight, double wing weight, breast muscle weight, leg weight, leg muscle weight, gizzard weight, breast muscle weight rate and / or weight after pluck. Body weight is an important economic trait of chicken, while shank length and body oblique length are strongly correlated with the size of chicken, and slaughter rate and eviscerated rate are the main indicators for measuring the meat production performance of livestock and poultry.

[0017] As a further improvement, the genotype of the SNP molecular marker is detected, and individuals with the SNP molecular marker AA or AG genotype are selected.

[0018] The beneficial effect of the above technical solution is that in practical application, the type of the 168th nucleotide from the 5' end of the sequence shown in SEQ ID NO.1 can be directly detected, and chicken individuals with homozygous AA at this site can be selected to establish a chicken population with excellent genetic resources.

[0019] In order to achieve the above object, the technical scheme of the detection primers for detecting the genotype of SNP molecular markers in the present invention is:

[0020] A detection primer for detecting the genotype of a SNP molecular marker, wherein the nucleotide sequence of the detection primer is shown in SEQ ID NOs. 2-3.

[0021] The beneficial effect of the above technical solution is that the above primers can be used to effectively amplify fragments containing SNP molecular markers related to chicken growth, body size and carcass traits, and assisted gene sequencing or restriction endonuclease digestion can be used to quickly detect and screen out AA homozygous chicken individuals.

[0022] In order to achieve the above object, the technical scheme of the kit for detecting the genotype of SNP molecular markers in the present invention is:

[0023] A kit for detecting SNP molecular marker genotypes, the kit comprising the above-mentioned detection primers and restriction endonuclease BsaBI.

[0024] The beneficial effect of the above technical solution is that: after analysis and verification, it was found that the above SNP molecular marker caused a restriction endonuclease BsaBI cleavage site. Therefore, the primers shown in SEQ ID NO.2~3 can be used to amplify the fragment containing the SNP molecular marker of the chicken to be tested, and then the restriction endonuclease BsaBI is used for cleavage, so the specific genotype of the site can be quickly and accurately determined.

[0025] As a further improvement, the kit further includes one or more of dNTPs, PCR reaction buffer, and DNA polymerase.

[0026] In order to achieve the above-mentioned object, the technical scheme of the application of the detection primer or the kit in the improvement breeding of chicken growth traits and / or carcass traits and / or body size traits in the present invention is:

[0027] The invention discloses an application of a detection primer or a test kit in improving breeding of chicken growth traits and / or carcass traits and / or body size traits.

[0028] The beneficial effect of the above technical scheme is that the detection primers and kit provided by the present invention can directly identify polymorphic sites, accurately, quickly, and time-savingly and labor-savingly detect the genotype of the SNP molecular marker at the site, the detection results are accurate and reliable, the operability is strong, the cost-effectiveness is high, the detection time is short, and it is suitable for large-scale promotion and use.

[0029] In order to achieve the above-mentioned object, the technical scheme of a method for improving the growth traits and / or carcass traits and / or body size traits of chickens in the present invention is:

[0030] A method for improving and breeding chicken growth traits and / or carcass traits and / or body size traits comprises the following steps: using genomic DNA of a chicken to be tested as a template, performing PCR amplification using detection primers shown in SEQ ID NO.2 and SEQ ID NO.3, performing enzyme digestion reaction on the PCR product using BsaBI endonuclease, if the enzyme digestion product is a 568 bp band, the SNP molecular marker is a homozygous GG type, if the enzyme digestion product is three bands of 568 bp, 403 bp and 165 bp, the SNP molecular marker is a heterozygous AG type, if the enzyme digestion product is two bands of 403 bp and 165 bp, the SNP molecular marker is a homozygous AA type; and selecting and retaining individuals with the homozygous AA genotype.

[0031] The beneficial effect of the above technical solution is that: using the above improved breeding method, the genotype of the SNP site can be predicted early and effectively, which helps to quickly select chickens with excellent growth traits, carcass traits and body size traits, thereby shortening the breeding time and accelerating the breeding process. It has great economic application value and scientific research value, and has broad application prospects in the improvement of chicken germplasm resources.

[0032] As a further improvement, the reaction system of the PCR amplification is: 5 μL of 2×Taq PCR MasterMix, 3 μL of ddH2O, 0.5 μL of each of the detection primers SEQ ID NO. 2-3, and 1 μL of DNA template.

[0033] The beneficial effects of the present invention are:

[0034] 1. The present invention first discovered a SNP site rs53587188 on the first intron of the chicken FGF2 gene, which has an A>G mutation. Further detection and analysis showed that the SNP site was significantly correlated with the growth, body size and carcass traits of chickens, and could be used as a molecular marker for genetic improvement of chicken breeds.

[0035] 2. The present invention designs specific PCR primers for amplification of the SNP molecular marker of the chicken FGF2 gene, performs enzyme digestion reaction on the amplified product, and then performs gel electrophoresis test to determine the genotype according to the number of bands; the amplified fragment can also be sequenced to obtain the genotype of the site, which can accurately, quickly, and save time and effort to detect the SNP molecular marker.

[0036] 3. The present invention provides a method for improving the breeding of chicken growth traits and / or carcass traits and / or body size traits, and the genotype of the SNP molecular marker can be determined according to the number of bands after PCR and enzyme cutting. The detection method is simple to operate, low in cost, and short in cycle. It can greatly improve the accuracy of SNP site genotype determination, does not require special instruments, has low technical requirements for detection personnel, is easy to promote and popularize, and has broad application prospects in the improvement of chicken germplasm resources. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is the agarose gel electrophoresis diagram of the PCR product in Experimental Example 2 of the present invention;

[0038] Figure 2 This is the sequencing peak diagram of individuals with different genotypes in Experimental Example 2 of the present invention;

[0039] Figure 3 This is the agarose gel electrophoresis phenotyping diagram of different genotypes in Experimental Example 2 of the present invention. DETAILED DESCRIPTION

[0040] The present invention is further described below in conjunction with specific embodiments, but the protection scope of the present invention is not limited thereto; however, these embodiments are only examples and do not constitute any limitation on the scope of the present invention. The details and forms of the present invention may be modified or replaced without departing from the spirit and scope of the present invention, but these modifications and replacements fall within the protection scope of the present invention. The test methods in the following embodiments are conventional methods unless otherwise specified. The test materials used in the following embodiments are purchased from conventional biochemical reagent manufacturers unless otherwise specified.

[0041] Biomaterials:

[0042] The Gushi chicken-Anka chicken F2 generation resource group was raised in the experimental chicken farm of Henan Agricultural University, and the slaughter experiment was completed in the poultry genetic improvement laboratory of Henan Agricultural University.

[0043] 1. Cultivation of biomaterials

[0044] The Gushi-Anka chicken resource group was established according to the F2 distant half-sib design scheme. A total of 7 families were established in the experiment, of which 4 orthogonal lines were Anka chicken ♂×Gushi chicken ♀, and 3 reciprocal lines were Gushi chicken ♂×Anka chicken ♀. The F0 generation was formed by selecting breeders from the pure lines of Gushi chickens for both egg and meat and Anka chickens for meat, and mating them at a ratio of 1:6 between male and female chickens. The selected male and female chickens were required to have the characteristics of this breed, high egg production, medium weight, and pure bloodline to ensure that the F1 generation individuals were heterozygous at each locus. A rooster was selected from the F1 offspring of each family, and mated with hens from other families at a ratio of 1:9 between male and female to produce the F2 generation. It was required that there was no genetic relationship between the mating male and female chickens. The breeding hens of the F1 generation were also scattered in various families as much as possible. When selecting, try to select individuals with rich appearance and heterozygous to ensure that the F2 generation traits have a large separation. The population includes 42 F0 generation chickens, 70 F1 generation chickens, and 860 F2 generation chickens. Among the resource population, there are 772 F2 generation individuals with complete economic traits.

[0045] 2. Feeding methods

[0046] Nutritional level of chickens during the feeding period: 0-4 weeks of age, energy level is 12.40MJ / kg, protein level is 20.1%; 5-8 weeks of age, energy level is 12.70MJ / kg, protein level is 18.2%; 9-12 weeks of age, energy level is 12.75MJ / kg, protein level is 16.0%. All families are mixed, caged, free to eat, and have plenty of drinking water.

[0047] Example 1 of a SNP molecular marker associated with chicken growth, body size and carcass traits

[0048] The nucleotide sequence of the SNP molecular marker related to chicken growth, body size and carcass traits in this embodiment is shown in SEQ ID NO.1, and the 168th base from the 5' end is A or G. The SNP molecular marker corresponds to the 53587188th deoxynucleotide (i.e., rs53587188 site) of the positive strand of chromosome 4 of the chicken reference genome GRCg6a version sequence information published by NCBI.

[0049] Example 1 of Application of SNP Molecular Markers in Breeding for Chicken Growth Traits and / or Carcass Traits and / or Body Size Traits

[0050] The SNP molecular marker of this embodiment is used in the improvement and breeding of chicken growth traits and / or carcass traits and / or body size traits. The genotype of the SNP molecular marker is detected, and individuals with the SNP molecular marker AA genotype are selected to establish a chicken population with excellent genetic resources.

[0051] Example 1 of a detection primer for detecting the genotype of a SNP molecular marker

[0052] The nucleotide sequence of the detection primer used to detect the genotype of the SNP molecular marker in this embodiment is as follows:

[0053] F Primer: 5'-CTGTTTGTCATCTTCTTGAACTGCG-3' (shown in SEQ ID NO. 2);

[0054] R Primer: 5′-GGCTGTAAAATTCTTTCCTCTACTGG-3′ (shown in SEQ ID NO. 3).

[0055] Example 1 of a kit for detecting SNP molecular marker genotypes

[0056] The kit for detecting the genotype of the SNP molecular marker of this embodiment includes detection primers with nucleotide sequences as shown in SEQ ID NO. 2-3 and restriction endonuclease BsaBI, and also includes dNTPs, PCR reaction buffer, and DNA polymerase.

[0057] Example 1 of the application of detection primers and detection kits in improving chicken growth traits and / or carcass traits and / or body size traits

[0058] The detection primers and the detection kit of this embodiment are used in the improvement and breeding of chicken growth traits and / or carcass traits and / or body size traits, and the genotype of the SNP molecular marker is detected, and individuals with the SNP molecular marker as the AA genotype are selected to establish a chicken population with excellent genetic resources.

[0059] Example 1 of a method for improving chicken growth traits and / or carcass traits and / or body size traits

[0060] A method for improving chicken growth traits and / or carcass traits and / or body size traits of this embodiment comprises the following steps:

[0061] (1) PCR amplification: using chicken whole genome DNA containing the FGF2 gene as a template, PCR amplification was performed using detection primers with nucleotide sequences as shown in SEQ ID NOs. 2 to 3;

[0062] (2) Enzyme digestion: After PCR amplification, restriction endonuclease BsaBI is used for digestion;

[0063] (3) Gel electrophoresis: Take the sample treated in step (2) and perform gel electrophoresis to determine the genotype based on the number of bands and perform molecular breeding.

[0064] If the enzyme digestion product is a single band of 568bp, the base at the mutation site is homozygous GG type; if the enzyme digestion product is three bands of 568bp, 403bp and 165bp, the base at the mutation site is heterozygous AG type; if the enzyme digestion product is two bands of 403bp and 165bp, the base at the mutation site is homozygous AA type; select individuals with homozygous AA genotype.

[0065] Experimental Example 1 Extraction and Detection of Chicken Genomic DNA

[0066] In this experimental example, genomic DNA was extracted from the F2 generation of the Gushi chicken-Anka chicken resource group, and the concentration of the extracted genomic DNA was detected by spectrophotometry. The specific operation steps are as follows:

[0067] 1. Extraction of genomic DNA

[0068] A total of 772 chickens of the F2 generation of Gushi chicken-Anka chicken resource group were used as materials. 5 mL of blood was drawn from the jugular vein of each chicken, anticoagulated with EDTA (10 mmol / L Tris-Cl, 0.2 mmol / L EDTA, PH 8.0), and stored at -80°C. Genomic DNA was extracted from blood samples of the F2 generation resource group using the phenol-chloroform extraction method, dissolved in TE buffer, and stored at 4°C for later use. The specific experimental steps are as follows:

[0069] (1) Take 80 μL of whole blood and place it in a 1.5 mL centrifuge tube. Add 500 μL of TE buffer, 10 μL of proteinase K (10 mg / mL), and 12 μL of 25% SDS lysis buffer. Mix by shaking for 10 min and place in a 55°C water bath overnight.

[0070] (2) Add an equal volume of Tris-saturated phenol, shake and mix for 10 min, and centrifuge at 10,000 rpm for 10 min;

[0071] (3) Take the supernatant, add an equal volume of Tris-saturated phenol, shake and mix for 10 min, and centrifuge at 10,000 rpm for 10 min;

[0072] (4) Take the supernatant, add an equal volume of phenol / chloroform / isoamyl alcohol mixed solution (25:24:1), shake and mix, and centrifuge at 10,000 rpm for 10 min;

[0073] (5) Take the supernatant, add an equal volume of phenol / chloroform mixed solution (24:1), shake and mix, and centrifuge at 10,000 rpm for 10 min;

[0074] (6) Take the supernatant, add 2 volumes of anhydrous ethanol precooled to -20°C, shake slightly, and centrifuge at 10,000 rpm for 10 min;

[0075] (7) Discard the supernatant, add 500 μL of 70% ethanol to wash the precipitate, invert and air-dry at room temperature, add an appropriate amount of TE (pH 8.0) to dissolve the DNA, store at 4°C until the DNA is completely dissolved, detect its quality by 1% agarose gel electrophoresis, and store at -80°C.

[0076] 2. Detection of genomic DNA concentration

[0077] Use a UV photometer to measure the OD value of the DNA sample at 260nm and 280nm. Calculate the DNA content and the ratio of OD260 / OD280. If the OD260 / OD280 ratio is less than 1.6, it means that the sample contains more protein or phenol, and purification should be performed; if the ratio is greater than 1.8, RNA purification should be considered.

[0078] DNA concentration (ng) = 50 × OD260 value × dilution multiple;

[0079] After the DNA test is completed, a certain amount is taken out and diluted to 100 ng / μL, and stored at -20°C for future use, and the rest is stored at -80°C.

[0080] Experimental Example 2 Detection of FGF2 gene mutation site

[0081] In this experimental example, the chicken genomic DNA extracted in Experimental Example 1 was randomly selected, and after mixing to construct a DNA pool, the chicken FGF2 gene fragment was amplified using amplification primers, the amplified fragment was sequenced, the sequencing results were analyzed, and then the restriction endonuclease BsaBI was used for genotyping. The specific operation steps are as follows:

[0082] 1. Construction of DNA pool

[0083] 100 DNA samples (with a concentration of 100 ng / μL) extracted from Experimental Example 1 were randomly selected, and 1 μL of DNA was extracted from each sample to form a DNA pool.

[0084] 2. Design of PCR primers

[0085] The chicken FGF2 gene genome sequence in GenBank was used as a reference (GRCg6a (GCF_000002315.6), GeneID: 396413 ), the sequencing PCR primer pair of chicken FGF2 gene was designed by NCBI, the total length of the amplified fragment was 568bp, and the agarose gel electrophoresis pattern of the PCR product used to detect the polymorphism was as follows: Figure 1 As shown in the figure, it can be seen that the designed primer pair has good specificity and there is no interference from primer dimers and miscellaneous bands.

[0086] The nucleotide sequences of the sequencing PCR primer pairs are:

[0087] F Primer: 5'-CTGTTTGTCATCTTCTTGAACTGCG-3' (shown in SEQ ID NO. 2);

[0088] R Primer: 5′-GGCTGTAAAATTCTTTCCTCTACTGG-3′ (shown in SEQ ID NO. 3).

[0089] 3. Cloning of Chicken FGF2 Gene Fragment

[0090] Using the DNA pool obtained in step 1 as a template and the sequencing PCR primer pair in step 2, PCR amplification (Touchdown PCR reaction) is performed. The reaction system of PCR amplification is shown in Table 1, and the reaction procedure is shown in Table 2.

[0091] Table 1 PCR reaction system

[0092]

[0093] Table 2 Touchdown PCR reaction procedure

[0094]

[0095]

[0096] 4. PCR product sequencing

[0097] After PCR amplification, agarose gel electrophoresis was performed, followed by gel excision, recovery and purification of the PCR product. The gel containing the target fragment was cut from the agarose gel under ultraviolet light, placed in a 2.0 mL centrifuge tube, and the PCR product was purified using a PCR product recovery and purification kit (Omega). The specific operation was carried out according to the instructions of the kit.

[0098] The PCR purified product was sent to Qingke Biotechnology Co., Ltd. (Beijing) for sequencing. The sequencing peak graph was analyzed and the sequence was compared. The results are as follows Figure 2 (The shadow in the figure indicates the mutation site). As shown in the figure, there is an A>G polymorphism in the FGF2 gene, which is the single nucleotide polymorphism of the chicken FGF2 gene screened, resulting in a BsaBI restriction endonuclease cleavage site.

[0099] 5. Genotyping using restriction endonuclease BsaBI

[0100] The products obtained by PCR amplification were used for restriction enzyme typing. The restriction enzyme reaction system was 15 μL. The specific reaction system is shown in Table 3.

[0101] Table 3 Enzyme digestion reaction system

[0102]

[0103] The enzyme digestion reaction conditions were: 60°C for 1.5 hours. After the enzyme digestion reaction, 2% agarose gel electrophoresis was performed, 120V voltage electrophoresis for 40 minutes, ethidium bromide (EB) staining detection, and gel imaging system SYNGENE GBOX, Kodak120 (Syngene, USA) for imaging. The individual genotype was determined based on the image of the electrophoresis band.

[0104] The cleavage sequence of BsaBI enzyme is 5'GATNNNNATC 3' (N = A, C, G or T). If the mutation site is A, the BsaBI cleavage sequence 5'GATNNNNATC 3' (N = A, C, G or T) exists; if the mutation site is G, the BsaBI cleavage sequence 5'GATNNNNATC 3' (N = A, C, G or T) does not exist.

[0105] Therefore, in the gel electrophoresis results, the AA genotype showed two bands of 403 bp and 165 bp; the AG genotype showed three bands of 568 bp, 403 bp and 165 bp, and the GG genotype showed one band of 568 bp. Figure 3 shown.

[0106] Experimental Example 3 Association analysis between SNP molecular markers related to chicken growth, body size and carcass traits and growth, carcass and body size traits

[0107] In this experiment, SPSS software was used to analyze the correlation between SNP molecular markers and growth (weight), carcass and body size traits, and an association analysis model was established. The specific steps are as follows:

[0108] Association analysis model: SPSS software was used to analyze the correlation between gene loci and growth (weight), carcass and body size traits. To ensure that the data of each trait was normally distributed, the least squares analysis was used to correct the data; according to the data characteristics, the multivariate linear model was used to analyze the genotype effect and the Benferroni multiple comparison method was used to compare the differences between genotypes. The results are shown in Tables 4, 5 and 6. Model I is the association analysis model between the polymorphism of the locus and growth traits and body size traits, and Model II is the association analysis model between the polymorphic locus and carcass traits, see formulas (1) and (2) for details.

[0109] Model I:y ijklm =μ + G i + S j + H k + f l + e ijklm (1)

[0110] Model II:

[0111] Where: y ijklm is the individual phenotypic value; μ is the overall mean; G i is the genotype fixed effect; S j is the gender effect; H k is the batch effect; f l is the family effect as a random effect; b is the regression coefficient of slaughter weight; W ijklm for individual slaughter weight; is the average body weight of the group, e ijklmn is a random error.

[0112] Table 4 Association analysis between different genotypes of A>G SNP loci and chicken growth traits

[0113]

[0114] Note: The same letters in the same column indicate no significant difference (P>0.05), and different letters indicate significant difference (P<0.05).

[0115] As shown in Table 4, different genotypes of the A>G mutation site rs53587188 of the FGF2 gene are significantly associated with body size traits and growth traits (birth weight, 2-12 week weight), and both show that the weight of individuals with AA and AG genotypes is higher than that of individuals with GG gene; there is no significant difference between the AA genotype and the AG genotype. The results show that the A allele is conducive to the increase of chicken weight, while the G allele is not conducive to the increase of chicken weight. The AA genotype at the rs53587188 site of the chicken FGF2 gene is a dominant genotype and can be used for marker-assisted selection breeding to increase chicken weight.

[0116] Table 5 Association analysis between different genotypes of A>G SNP loci and chicken carcass traits

[0117]

[0118] Note: The same letters in the same column indicate no significant difference (P>0.05), and different letters indicate significant difference (P<0.05).

[0119] As shown in Table 5, different genotypes of the A>G mutation site rs53587188 of the FGF2 gene were significantly correlated with carcass traits, and almost all showed that the carcass traits of individuals with AA genotype and AG genotype were higher than those of individuals with GG genotype, and the carcass traits of individuals with AA genotype and AG genotype were not significantly different. This indicates that the A allele is beneficial to the growth of chicken carcasses. The AA genotype at the rs53587188 site of the chicken FGF2 gene is a dominant genotype and can be used for marker-assisted selection breeding to improve chicken carcasses.

[0120] Table 6 Association analysis between different genotypes of A>G SNP loci and chicken body size traits

[0121]

[0122]

[0123] Note: The same letters in the same column indicate no significant difference (P>0.05), and different letters indicate significant difference (P<0.05).

[0124] As shown in Table 6, different genotypes of the A>G mutation site rs53587188 of the FGF2 gene are significantly associated with body size traits, and almost all of them show that the body size traits of individuals with AA genotype and AG genotype are higher than those of individuals with GG genotype. The body size traits of individuals with AA genotype and AG genotype are not significantly different, and the body size traits of individuals with AA genotype and GG genotype are significantly different (P < 0.05). This shows that the A allele is beneficial to the growth of chicken body size. The AA genotype at the rs53587188 site of the chicken FGF2 gene is a dominant genotype and can be used for marker-assisted selection breeding to improve the body size traits of chickens.

[0125] In summary, based on the above analysis, the tested chickens were selected and bred to select superior varieties. Specifically, the AA homozygous individuals at the SNP (rs53587188) site of the chicken FGF2 gene were selected to improve the economic performance of the chickens; the AG heterozygous and GG homozygous individuals were eliminated, and the AA homozygous individuals were selected.

[0126] Finally, it is noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. An application of a SNP molecular marker related to chicken growth, body size and carcass traits in improving chicken growth traits and / or carcass traits and / or body size traits in breeding, characterized in that: The nucleotide sequence of the SNP molecular marker is shown in SEQ ID NO.1, and the 168th base from the 5' end is A or G; the growth traits are birth weight, 2-week weight, 4-week weight, 6-week weight, 8-week weight, 10-week weight and 12-week weight; the carcass traits are half-eviscerated weight, full-week weight, claw weight, double-wing weight, gizzard weight, breast muscle weight, leg weight, leg muscle weight, breast muscle weight rate and weight after depilation; the body size traits are 4-week shank length, 8-week shank length, 12-week shank length, 4-week shank circumference, 8-week shank circumference, 4-week chest depth, 4-week chest width, 8-week chest width, 12-week chest width, 8-week sternum length, 12-week sternum length, 8-week chest angle, 4-week body oblique length, 8-week body oblique length and 12-week body oblique length; the chicken is a Gushi chicken-Anka chicken F2 generation resource group.

2. The use of the SNP molecular marker according to claim 1 in improving breeding of chicken growth traits and / or carcass traits and / or body size traits, characterized in that: The genotype of the SNP molecular marker is detected, and individuals with the SNP molecular marker as the AA genotype are selected.

3. Use of a detection primer for detecting the genotype of a SNP molecular marker related to chicken growth, body size and carcass traits or a kit for detecting the genotype of a SNP molecular marker related to chicken growth, body size and carcass traits in improving breeding of chicken growth traits and / or carcass traits and / or body size traits, characterized in that: The nucleotide sequence of the detection primer is shown in SEQ ID NO.2-3; the kit includes the detection primer with the nucleotide sequence shown in SEQ ID NO.2-3 and the restriction endonuclease BbI ; The growth traits are birth weight, 2-week body weight, 4-week body weight, 6-week body weight, 8-week body weight, 10-week body weight and 12-week body weight; the carcass traits are half-eviscerated weight, full-eviscerated weight, claw weight, double-wing weight, gizzard weight, breast muscle weight, leg weight, leg muscle weight, breast muscle weight rate and body weight after depilation; the body size traits are shank length at 4 weeks, shank length at 8 weeks, shank length at 12 weeks, shank circumference at 4 weeks, shank circumference at 8 weeks, chest depth at 4 weeks, chest width at 4 weeks, chest width at 8 weeks, chest width at 12 weeks, sternum length at 8 weeks, sternum length at 12 weeks, chest angle at 8 weeks, oblique body length at 4 weeks, oblique body length at 8 weeks and oblique body length at 12 weeks; the chicken is a Gushi chicken-Anka chicken F2 generation resource group.

4. Use of the detection primers for detecting the genotype of SNP molecular markers related to chicken growth, body size and carcass traits or the kit for detecting the genotype of SNP molecular markers related to chicken growth, body size and carcass traits according to claim 3 in improving breeding of chicken growth traits and / or carcass traits and / or body size traits, characterized in that: The kit also includes one or more of dNTPs, PCR reaction buffer, and DNA polymerase.

5. A method for improving chicken growth traits and / or carcass traits and / or body size traits, characterized in that: The following steps are involved: The genomic DNA of the chicken to be tested was used as a template, and PCR amplification was performed using the detection primers shown in SEQ ID NO.2 and SEQ ID NO.

3. The PCR product was amplified by BbI The endonuclease was used for enzyme digestion reaction. If the enzyme digestion product was a single band of 568 bp, the SNP molecular marker was homozygous GG type. If the enzyme digestion product was three bands of 568 bp, 403 bp and 165 bp, the SNP molecular marker was heterozygous AG type. If the enzyme digestion product was three bands of 403 bp and 165 bp two bands, the SNP molecular marker is homozygous AA type; AA homozygous genotype individuals are selected; the growth traits are birth weight, 2-week body weight, 4-week body weight, 6-week body weight, 8-week body weight, 10-week body weight and 12-week body weight; the carcass traits are half-eviscerated weight, full-eviscerated weight, claw weight, double-wing weight, gizzard weight, breast muscle weight, leg weight, leg muscle weight, breast muscle weight rate and body weight after depilation; the body size traits are 4-week shank length, 8-week shank length, 12-week shank length, 4-week shank circumference, 8-week shank circumference, 4-week chest depth, 4-week chest width, 8-week chest width, 12-week chest width, 8-week sternum length, 12-week sternum length, 8-week chest angle, 4-week body oblique length, 8-week body oblique length and 12-week body oblique length; the chicken is a Gushi chicken-Anka chicken F2 generation resource group.

6. The method for improving chicken growth traits and / or carcass traits and / or body size traits according to claim 5, characterized in that: The reaction system of the PCR amplification is: 5 μL of 2×Taq PCR MasterMix, 3 μL of ddH2O, 0.5 μL of each of the detection primers SEQ ID NO.2-3, and 1 μL of DNA template.

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