Molecular marker linked with wheat gibberellic disease-resistant gene Qfhb.jaas-6B, primer group and application of molecular marker

Abstract

The invention belongs to the technical field of wheat disease-resistant breeding, and particularly relates to a molecular marker linked with a wheat gibberellic disease-resistant gene Qfhb.jaas-6B, a primer group and application of the molecular marker. The molecular marker is located on a long arm of a wheat 6B chromosome, when wheat is wheat susceptible to gibberellic disease, the 702386391th nucleotide of the wheat 6B chromosome is T, and the nucleotide sequence of the molecular marker is as shown in SEQ ID No.1; when the wheat is wheat resistant to gibberellic disease, the 702386391th nucleotide of the 6B chromosome is C, and the nucleotide sequence of the molecular marker is shown as SEQ ID No.2; the primer group consists of a front primer 1 with a nucleotide sequence as shown in SEQ ID No.5, a front primer 2 with a nucleotide sequence as shown in SEQ ID No.6 and a rear primer with a nucleotide sequence as shown in SEQ ID No.7.

Description

Technical Field

[0001] The invention belongs to the technical field of wheat disease resistance breeding, and specifically relates to a molecular marker linked to a wheat scab resistance gene Qfhb.jaas-6B, a primer set and application thereof. Background Art

[0002] Fusarium head blight (FHB) is one of the major wheat diseases worldwide caused by Fusarium graminearum. It not only causes a serious reduction in wheat production, but also produces "vomiting toxin" (mainly deoxynivalenol (DON)) that poses a serious threat to the health of humans and animals, thus posing a serious threat to wheat production and food safety.

[0003] Wheat fusarium head blight resistance is mainly divided into five types: resistance to infection (type I), resistance to spread (type II), resistance to toxin accumulation (type III), resistance to grain infection (type IV) and resistance to yield reduction (type V). Among them, the resistance to spread type has been widely and deeply studied because of its simple identification method and high genetic stability. To date, about 70,000 germplasms of common wheat and its closely related species have been identified under artificial inoculation or natural disease conditions worldwide, and about 7,000 germplasms have different degrees of resistance to fusarium head blight. Wheat fusarium head blight resistance is a quantitative trait controlled by multiple genes. Through linkage analysis and association analysis, about 432 fusarium head blight resistance loci (covering type I to type V) have been located in common wheat and its closely related species, covering 44 chromosome segments on 21 chromosomes of wheat. At present, the named QTLs for resistance to fusarium head blight include the resistance expansion site Fhb1 from Sumai 3 3BS, the resistance expansion site Fhb2 from Sumai 3 derived line BW278 6BS, the resistance expansion site Fhb3 from Leymus dahurica 7Lr#1S, the resistance infection site Fhb4 from Wangshuibai 4B and the resistance infection site Fhb5 from 5A, the resistance expansion site Fhb6 from Elymus 1E(ts)#1S, and the resistance expansion site Fhb7 from the long arm of Elymus longipedalis 7E. Among them, Fhb1 and Fhb7 have been cloned, and Fhb2, Fhb4 and Fhb5 have been precisely located. At present, the major effect genes for resistance to fusarium head blight in wheat are extremely scarce at home and abroad. Since Fhb1 is relatively stable in different environments and genetic backgrounds, and the phenotypic contribution rate is between 15% and 30%, the current worldwide wheat resistance improvement work is still carried out with Fhb1 as the main resistance source, and the resistance source used is relatively single. In the prior art, the major fusarium ergot resistance gene Fhb7 carried on the long arm of chromosome 7E of Elytrimus elongatus has been cloned. The cloning of Fhb7 will effectively promote the progress of wheat fusarium ergot resistance breeding in my country. However, relying on only a few resistance genes is not enough to effectively reduce the damage in years when fusarium ergot is severely prevalent. Aggregating multiple resistance genes with large and stable effects into varieties (lines) with good yields and achieving the accumulation of resistance effects is an effective way to improve wheat fusarium ergot resistance. Therefore, identifying new fusarium ergot resistance genes, accurately locating them, and evaluating their genetic effects are still urgent tasks now faced.

[0004] In the early stage of this study, 326 Chinese wheat local varieties were identified for resistance to fusarium head blight (resistance to extension) for 6 years. Through 55K SNP chip genotyping and genome-wide association analysis (GWAS) methods, several new fusarium head blight resistance loci were identified, among which the new locus located on 6BL had the largest effect (can explain 19.4% of phenotypic variation; about 500Mb away from Fhb2, not the same gene), slightly higher than the major gene Fhb1 (~18.8%), and was named Qfhb.jaas-6B. At the same time, the disease-resistant wheat local variety Jianzimai was hybridized with the susceptible wheat Shannong 931 to construct an F8 family population. Through resistance identification, molecular marker technology and genetic map positioning, the disease resistance gene was once again located on the long arm of chromosome 6B, contributed by Jianzimai. The development of new molecular markers closely linked to this locus will lay the foundation for the isolation and effective use of this gene. Summary of the invention

[0005] The technical problem to be solved by the present invention is to provide a molecular marker, primer and application thereof which are tightly linked to the wheat ergot resistance gene Qfhb.jaas-6B in view of the deficiencies in the prior art, and to screen and find new and stable molecular markers which are tightly linked to the ergot resistance gene and a method thereof by using the ergot-resistant wheat variety Jianzimai as disease-resistant material, and to use them for wheat ergot-assisted selection breeding, thereby overcoming the shortcomings of conventional genetic breeding such as a long cycle.

[0006] In order to solve the above technical problems, the present invention discloses a molecular marker tightly linked to the wheat scab resistance gene Qfhb.jaas-6B, wherein the molecular marker is located on the long arm of wheat chromosome 6B, and when the wheat is susceptible to scab, the 702386391st nucleotide of the wheat chromosome 6B is T, and the nucleotide sequence of the molecular marker is shown in SEQ ID No.1; when the wheat is scab-resistant wheat, the 702386391st nucleotide of the 6B chromosome is C, and the nucleotide sequence of the molecular marker is shown in SEQ ID No.2;

[0007] Specifically, the molecular marker is obtained by amplification of the following three primers, wherein the three primers include two front primers and one back primer, and the 5' ends of the two front primers contain different fluorescent groups respectively; the nucleotide sequences of the three primers are shown as SEQ ID No.5 to SEQ ID No.7 respectively;

[0008] The present invention also provides a primer set of a molecular marker tightly linked to the wheat fusarium resistant gene Qfhb.jaas-6B, the primer set consisting of a front primer 1 with a nucleotide sequence as shown in SEQ ID No.5, a front primer 2 with a nucleotide sequence as shown in SEQ ID No.6 and a rear primer with a nucleotide sequence as shown in SEQ ID No.7.

[0009] Furthermore, the application of the above molecular markers and primer sets in identifying wheat ergot resistance is also within the protection scope of the present invention.

[0010] Furthermore, the use of the above molecular markers or primer sets in breeding wheat germplasm with resistance to ergot disease is also within the protection scope of the present invention.

[0011] The present invention also protects a method for identifying wheat resistance to ergot disease, which uses the above-mentioned molecular markers or primer sets to detect whether the wheat DNA sample to be tested carries the wheat ergot disease resistance gene Qfhb.jaas-6B; when the wheat DNA sample to be tested carries the wheat ergot disease resistance gene Qfhb.jaas-6B, it indicates that the wheat to be tested has resistance to ergot disease.

[0012] Specifically, the genomic DNA of the wheat to be tested is used as a template, and the above primer set is used to perform fluorescence quantitative PCR amplification to obtain an amplified product, and the obtained amplified product is subjected to fluorescence signal scanning, and the scanning data is analyzed to obtain a scatter plot; when the genotype appears in the X-axis area in the scatter plot, it indicates that the wheat is a FAM genotype variety, and the wheat scab resistance is weak; when the genotype appears in the Y-axis area, it indicates that the wheat is a HEX genotype variety, and the wheat scab resistance is strong;

[0013] Specifically, the fluorescent quantitative PCR amplification refers to:

[0014] The reaction system for PCR amplification was: 2.5 μl of template DNA at a concentration of 20 ng / μl, 0.07 μl of KASP assay mix, and 2.5 μl of 2×KASP master mix;

[0015] The configuration method of each 100 μl of KASP assay mix is ​​as follows: 12 μl of the front primer 1 with a concentration of 100 μM, 12 μl of the front primer 2 with a concentration of 100 μM, 30 μl of the back primer with a concentration of 100 μM, and 46 μl of Tris-HCL with a concentration of 10 mM and a pH of 8.3;

[0016] The PCR reaction cycle program was as follows: pre-denaturation at 94°C for 15 min, followed by 10 cycles of “94°C, 20 s; 65-57°C, 60 s, decreasing by 0.8°C each cycle”; and finally 32 cycles of amplification at “94°C, 20 s; 57°C, 60 s”.

[0017] Fluorescence analysis of PCR products was performed using the PHERAstar (LGC Genomics) instrument, and finally typing was performed using the KlusterCaller (LGC Genomics) software.

[0018] The present invention also protects a method for breeding wheat carrying the ergot resistance gene Qfhb.jaas-6B, using the above primer set to PCR amplify wheat leaf DNA, and selecting a variety with a HEX genotype as a result of the above molecular marker detection;

[0019] The primers are primers of a KASP marker KASP_W6041 which is closely linked to the wheat fusarium head blight resistance gene Qfhb.jaas-6B, and the physical distance between the marker KASP_W6041 and the target gene is less than 1.44 Mb.

[0020] The present invention also protects a kit for identifying the wheat fusarium head blight resistance gene Qfhb.jaas-6B, wherein the kit contains the primer set.

[0021] The molecular marker primers are used to PCR amplify wheat plant DNA using the primers of the KASP marker KASP_W6041 that is tightly linked to the wheat scab resistance gene Qfhb.jaas-6B. If the HEX genotype of the KASP_W6041 marker (the same as that of the sword wheat) appears, it indicates that the wheat scab resistance gene Qfhb.jaas-6B exists in the plant. The application is to amplify wheat plant DNA using sword wheat, Shannong 931 and its recombinant inbred line.

[0022] Beneficial effects:

[0023] Fusarium head blight (FHB) is one of the major wheat diseases worldwide caused by Fusarium graminearum, which not only causes a serious reduction in wheat production, but also can cause serious harm to the health of humans and animals. In the early stage of the present invention, 326 Chinese wheat local varieties were identified for resistance to fusarium head blight (resistance to expansion) for a period of 6 years. Through 55KSNP chip genotyping and genome-wide association analysis (GWAS) methods, a new site located on 6BL (which can explain 19.4% of the phenotypic variation; not Fhb2) was identified and named Qfhb.jaas-6B. At the same time, the F8 family population was constructed by hybridizing the disease-resistant wheat local variety Jianzimai with the susceptible wheat Shannong 931. Through the identification of the expansion of fusarium resistance at two points in three years, 55K SNP chip genotyping, genetic map construction and QTL positioning, the disease resistance gene was repeatedly located in the interval AX-10898713 to AX-109459603 on the long arm of chromosome 6B, and the physical distance of this interval is 1.44Mb. The present invention uses molecular marker methods to develop a new KASP marker that is confidentially linked to wheat fusarium resistance, which has important value in wheat breeding practice and disease resistance theory research. Its advantages are specifically summarized as follows:

[0024] (1) The KASP marker tightly linked to the wheat ergot resistance gene Qfhb.jaas-6B in the present invention is a new marker obtained in a single plant of a hybrid of the wheat variety Jianzimai and its stable resistance, and is stable in existence, and can be used for identification of wheat ergot varieties and auxiliary selection breeding of wheat disease-resistant offspring.

[0025] (2) The material used in this study, Triticum aestivum, is a new source of resistance to Fusarium fusarium. Based on this molecular marker, it is expected that new Fusarium fusarium resistance genes will be discovered.

[0026] (3) The marker is a stable KASP marker, which is closely linked to the ergot resistance gene with a genetic distance of ≤1.44Mb. It can be directly used in molecular marker-assisted selection breeding for wheat ergot resistance, accelerating the breeding process. It also lays a good foundation for cloning new wheat ergot resistance genes and studying their functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The present invention will be further described in detail below in conjunction with the accompanying drawings and specific embodiments, and the above and / or other advantages of the present invention will become more clear.

[0028] Figure 1 The genetic linkage and physical map of Qfhb.jaas-6B in the embodiment of the present invention, wherein W6041 is tightly linked to Qfhb.jaas-6B;

[0029] Figure 2 This is a scatter plot of identification and segregation of the KASP_W6041 marker in the F8 generation recombinant inbred line population of Jianzimai×Shannong 931 in the embodiment of the present invention, wherein the HEX genotype indicates that the fusarium head blight resistance allele exists in the plant;

[0030] Figure 3 This is a scatter plot of identification and separation of the KASP_W6041 marker in 326 Chinese wheat local varieties in the embodiment of the present invention, wherein the HEX genotype indicates that the fusarium head blight resistance allele exists in the plant;

[0031] Figure 4 The figure is a comparison of the resistance to Fusarium head blight of two genotypes, FAM and HEX, in 326 Chinese wheat local varieties in the examples of the present invention. DETAILED DESCRIPTION

[0032] The experimental methods described in the following examples are conventional methods unless otherwise specified; the reagents and materials described are commercially available unless otherwise specified.

[0033] The 326 Chinese wheat local varieties used in the following examples are all germplasm resource materials preserved in the Jiangsu Agricultural Germplasm Resource Bank of the Germplasm Resources and Biotechnology Institute of Jiangsu Academy of Agricultural Sciences, and can be obtained and used by those skilled in the art.

[0034] The wheat varieties Shannong 931 and Jianzimai used in the following examples are both preserved and provided by the Wheat Germplasm Resources Innovation Team of the Institute of Germplasm Resources and Biotechnology, Jiangsu Academy of Agricultural Sciences, and can be obtained and used by those skilled in the art.

[0035] The method for evaluating resistance to fusarium spores in the following embodiments is as follows: inoculation is performed using a mixed spore solution of four fusarium spore strains (F0609, F0301, F0908, and F1126), with a spore solution concentration of 100 / μl. Fusarium spores were inoculated in a fusarium spore identification nursery. In the early flowering period of wheat, single flower dripping method was used for inoculation, i.e., a continuous syringe (Hamilton) was used to inject 10 μL (~1000) of fusarium spores into a small flower of the spikelet in the middle of the wheat ear. 15 to 20 spikelets were inoculated for each strain. After inoculation, the bag was moisturized for 72 hours to ensure the temperature and humidity required for the onset of the disease. The bag was removed after 72 hours, and the fusarium spore phenotype was investigated 21 days after inoculation. The calculation formula for the rate of diseased spikelets with fusarium spores resistance to expansion (type II) is as follows:

[0036]

[0037] The method for extracting genomic DNA in the following examples refers to the CTAB extraction method of Sagfai-Maroof et al. (1984) (Saghai-Maroof, K., Soliman, M., Jorgensen, RA and Allard, RW (1984) Ribosomal DNA spacer-length polymorphisms in barley: Mendelian inhertance, chromosomal allocation, and population dynamics. Proceedings of the National Academy of Science of the United States of America, 81, 8014-8018.), and total DNA is extracted from young leaves.

[0038] In the following examples, PCR amplification reactions were performed on a ThermoFisher thermal cycler, and the reaction system was 5.07 μL, containing 2.5 μL of DNA template (~20 ng / μL), 0.07 μL of KASP assay mix (12 μL (100 μM) of each allele-specific forward primer, 30 μL (100 μM) of the rear primer, and 46 μL of Tris-HCL (10 mM, pH 8.3)), and 2.5 μL of 2×KASP master mix from LGC Genomics;

[0039] The reaction cycle program was as follows: pre-denaturation at 94°C for 15 min, followed by 10 cycles of "94°C, 20 s; 65-57°C, 60 s (0.8°C decrease for each cycle)"; finally, 32 cycles of amplification at "94°C, 20 s; 57°C, 60 s"; fluorescence analysis of PCR products was performed using the PHERAstar (LGC Genomics) instrument, and finally, typing was performed using the KlusterCaller (LGC Genomics) software.

[0040] Example 1: Construction of molecular markers linked to wheat scab resistance genes and their corresponding primers

[0041] In the early stage of the present invention, 326 Chinese wheat local varieties were identified for 6 years of fusarium resistance (anti-expansion) in the fusarium identification nursery of Liuhe base. Each variety was planted in one row, 20 grains per row, 0.6 meters in length, 0.25 meters in row spacing, and 2 repetitions were set. Genotyping was obtained through a 55K SNP chip, and population structure analysis was performed using Structure2.3.4 software. Tassel software was used, principal component analysis (PCA) and kinship matrix (K) were used as covariates, and genome-wide association analysis (GWAS) was performed on the fusarium trait under the MLM model. In the results, P≤0.001 was used as a significant association between genotype and phenotype. A new site located on 6BL (which can explain 19.4% of the phenotypic variation; not Fhb2) was identified and named Qfhb.jaas-6B.

[0042] Using Shannong 931 as the fusarium susceptible / moderately susceptible material and Chinese wheat local variety Jianzimai as the fusarium resistant material, a hybrid combination was prepared to construct 213 Jianzimai×Shannong 931F8 generation recombinant inbred line (RIL) populations as materials. From 2022 to 2024, the population was identified for fusarium resistant expansion in Liuhe base and Nanjing field for three consecutive years. Each line was planted in one row, 20 grains per row, 0.6 meters long, 0.25 meters apart, and 2 replicates were set. Through 55K SNP chip genotyping, the Kosambi mapping function of Joinmap V4.1 software was used to construct a linkage map with LOD=3.0 as the threshold. The software QTL IciMapping v4 was used to locate the QTL for fusarium resistance, and the complete interval mapping method (ICIM-ADD) was used, with an LOD value of 2.5 as the threshold of significance. A new locus with a large and stable resistance to Fusarium head blight was located on the long arm of chromosome 6B and named Qfhb.jaas-6B. Its genetic location is as follows Figure 1 As shown, since the sequence obtained by SNP chip sequencing is short, the present invention searches and compares the reference genome sequence of common wheat Chinese Spring (IWGSC RefSeq v1.0) through the sequence to obtain a long sequence fragment containing the SNP site. At this time, the new site for resistance to ergot is located in the interval AX-10898713 to AX-109459603 on the long arm of chromosome 6B, and the physical distance of this interval is 1.44Mb.

[0043] The software Primer 6.0 was used to convert the tightly linked SNP markers into KASP markers KASP_W6041 and design the corresponding primer sets. The specific marker information is shown in Table 1:

[0044] Table 1 Molecular marker information

[0045]

[0046]

[0047] The primer set information is shown in Table 2. The primer set consists of three sequences, namely, front primer 1: FAM tag sequence + amplification primer sequence; front primer 2: HEX tag sequence + amplification primer sequence; rear primer: amplification primer sequence;

[0048] The nucleotide sequences of the FAM tag sequence and the HEX tag sequence are as follows:

[0049] FAM tag sequence (SEQ ID No. 3): 5′-GAAGGTGACCAAGTTCATGCT-3′;

[0050] HEX tag sequence (SEQ ID No. 4): 5′-GAAGGTCGGAGTCAACGGATT-3′;

[0051] Table 2 Primer sequences used to amplify molecular marker KASP_W6041

[0052]

[0053] The designed KASP marker and primer set were able to detect polymorphism between the two parents and relocate it to the genetic map of Qfhb.jaas-6B.

[0054] Example 2: Application of molecular marker KASP_W6041 in detection of scab resistance gene

[0055] In order to verify the feasibility of KASP_W6041 marker in detecting wheat scab resistance genes, this example uses KASP_W6041 marker to detect 213 Jianzimai×Shannong 931F8 recombinant inbred lines and two parents. By reading the fluorescence signal of the KASP marker amplification product, the fluorescence scanning results are obtained, and the scanning data are analyzed using Kluster Caller software. The varieties in the X-axis area of ​​the scatter plot are "FAM" genotypes, the varieties in the Y-axis area are "HEX" genotypes, and the varieties between the two areas are heterozygous genotypes ( Figure 2 ).

[0056] KASP is a competitive allele-specific PCR (Kompetitive Allele Specific PCR), which can accurately determine the biallelicity of SNPs. KASP analysis requires the following three elements: 1. KASP assay mix is ​​composed of two forward primers with different terminal bases and one reverse primer, and the 5' ends of the two forward primers are connected to different detection primer sequences; 2. Master Mix contains two detection primers with different fluorescence (FAM and HEX); 3. DNA template. The detection primers corresponding to the specific sequence in the PCR reaction increase as the PCR reaction proceeds, thereby generating corresponding fluorescent signals. The fluorescence analysis PCR product is read using the PHERAstar (LGC Genomics) instrument, and finally the KlusterCaller (LGC Genomics) software is used for typing to obtain a scatter plot.

[0057] The results showed that the genotypes obtained by using the KASP_W6041 marker were completely consistent with the original 55K chip results (Table 3). This result showed that the KASP_W6041 marker can be used to detect the wheat fusarium head blight resistance gene Qfhb.jaas-6B and be applied to molecular marker-assisted breeding of wheat fusarium head blight resistance.

[0058] Table 3 Comparison of KASP_W6041 marker and 55K SNP chip genotypes in 213 Wheat × Shannong 931 F8 recombinant inbred lines

[0059]

[0060]

[0061]

[0062]

[0063] Example 3: Application of molecular marker KASP_W6041 in screening of wheat germplasm resources resistant to scab

[0064] In order to verify the application of KASP_W6041 marker in the screening of wheat germplasm resources resistant to scab, and whether it can be used for genetic improvement of wheat varieties resistant to scab, this example uses KASP_W6041 marker to detect 326 Chinese wheat local variety germplasm resources, and obtains fluorescence scanning results by reading the fluorescence signal of KASP marker amplification products. The scanning data are analyzed using Kluster Caller software. The varieties in the X-axis area of ​​the scatter plot are "FAM" genotypes (not carrying Qfhb.jaas-6B), and the varieties in the Y-axis area are "HEX" genotypes (carrying Qfhb.jaas-6B) ( Figure 3 ).

[0065] KASP is a competitive allele-specific PCR (Kompetitive Allele Specific PCR), which can accurately determine the biallelicity of SNPs. KASP analysis requires the following three elements: 1. KASP assay mix is ​​composed of two forward primers with different terminal bases and one reverse primer, and the 5' ends of the two forward primers are connected to different detection primer sequences; 2. Master Mix contains two detection primers with different fluorescence (FAM and HEX); 3. DNA template. The detection primers corresponding to the specific sequence in the PCR reaction increase as the PCR reaction proceeds, thereby generating corresponding fluorescent signals. The fluorescence analysis PCR product is read using the PHERAstar (LGC Genomics) instrument, and finally the KlusterCaller (LGC Genomics) software is used for typing to obtain a scatter plot.

[0066] The results showed that the genotyping of 326 Chinese wheat landrace germplasm resources by KASP_W6041 marker was divided into two groups, of which 231 germplasms (70.86%) such as Huoshaotian and Shaannong 7859 were of "FAM" type, while 95 germplasms (29.14%) such as Ruanganyangmai and Wugongmai were of "HEX" type ( Figure 3 ). The "HEX" type, which represents the disease-resistant gene Qfhb.jaas-6B, only accounts for 29.14% of the total, indicating that most wheat germplasm resources lack the resistance gene Qfhb.jaas-6B to ergot disease. The results of the field ergot disease resistance identification of the above 326 wheat germplasm resources were statistically analyzed. The results showed that the average ergot disease spikelet rate of varieties containing the Qfhb.jaas-6B gene was 19.23%, while the average ergot disease index of varieties without the Qfhb.jaas-6B gene was 38.90%. The difference in the ergot disease spikelet rate between the two reached an extremely significant level ( Figure 4 , Table 4). This result indicates that the Qfhb.jaas-6B marker can be used for the detection of wheat fusarium rust gene Qfhb.jaas-6B and its molecular marker-assisted breeding.

[0067] Table 4 Average diseased spikelet rate and KASP typing results of fusarium head blight in 326 varieties

[0068]

[0069]

[0070]

[0071] The present invention provides a molecular marker, primer set and application idea linked to wheat scab resistance gene Qfhb.jaas-6B. There are many methods and approaches to realize the technical solution. The above is only a preferred embodiment of the present invention. It should be pointed out that for ordinary technicians in this technical field, several improvements and modifications can be made without departing from the principle of the present invention. These improvements and modifications should also be regarded as the protection scope of the present invention. All components not specified in this embodiment can be realized by existing technologies.

Claims

1. A molecular marker tightly linked to the wheat fusarium head blight resistance gene Qfhb.jaas-6B, characterized in that: The molecular marker is located on the long arm of wheat chromosome 6B. When the wheat is susceptible to ergot, the 702386391st nucleotide of the wheat chromosome 6B is T, and the nucleotide sequence of the molecular marker is shown in SEQ ID No.1; when the wheat is resistant to ergot, the 702386391st nucleotide of the chromosome 6B is C, and the nucleotide sequence of the molecular marker is shown in SEQ ID No.

2.

2. The molecular marker according to claim 1, characterized in that The molecular marker is obtained by amplification using the following three primers, wherein the three primers include two front primers and one back primer, and the 5' ends of the two front primers contain different fluorescent groups respectively; the nucleotide sequences of the three primers are shown in SEQ ID No.5 to SEQ ID No.7 respectively.

3. A primer set of a molecular marker tightly linked to the wheat fusarium rust resistance gene Qfhb.jaas-6B, characterized in that: The primer set consists of a front primer 1 whose nucleotide sequence is shown as SEQ ID No.5, a front primer 2 whose nucleotide sequence is shown as SEQ ID No.6, and a rear primer whose nucleotide sequence is shown as SEQ ID No.

7.

4. Use of the molecular marker according to claim 1 or 2 or the primer set according to claim 3 in identifying resistance to wheat fusarium head blight.

5. Use of the molecular marker according to claim 1 or 2 or the primer set according to claim 3 in breeding wheat germplasm with resistance to ergot disease.

6. A method for identifying wheat resistance to scab, characterized in that: The molecular marker described in claim 1 or 2 or the primer set described in claim 3 is used to detect whether the wheat DNA sample to be tested carries the wheat ergot resistance gene Qfhb.jaas-6B; when the wheat DNA sample to be tested carries the wheat ergot resistance gene Qfhb.jaas-6B, it indicates that the wheat to be tested has ergot resistance.

7. The identification method according to claim 6, characterized in that: The genomic DNA of the wheat to be tested is used as a template, and the primer set described in claim 3 is used to perform fluorescent quantitative PCR amplification to obtain an amplified product, and the obtained amplified product is subjected to fluorescent signal scanning, and the scanning data is analyzed to obtain a scatter plot; when the genotype appears in the X-axis area in the scatter plot, it indicates that the wheat is a FAM genotype variety and has weak resistance to wheat fusarium rust; when the genotype appears in the Y-axis area, it indicates that the wheat is a HEX genotype variety and has strong resistance to wheat fusarium rust.

8. The identification method according to claim 7, characterized in that: The fluorescent quantitative PCR amplification refers to: The reaction system for PCR amplification was: 2.5 μl of template DNA at a concentration of 20 ng / μl, 0.07 μl of KASP assay mix, and 2.5 μl of 2×KASP master mix; The configuration method of each 100 μl of KASP assay mix is ​​as follows: 12 μl of the front primer 1 with a concentration of 100 μM, 12 μl of the front primer 2 with a concentration of 100 μM, 30 μl of the back primer with a concentration of 100 μM, and 46 μl of Tris-HCL with a concentration of 10 mM and a pH of 8.3; The PCR reaction cycle program was as follows: pre-denaturation at 94°C for 15 min, followed by 10 cycles of "94°C, 20 s; 65-57°C, 60 s, decreasing by 0.8°C each cycle"; and finally 32 cycles of amplification at "94°C, 20 s; 57°C, 60 s".

9. A method for breeding wheat carrying the fusarium head blight resistance gene Qfhb.jaas-6B, characterized in that: The primer set described in claim 3 is used to PCR amplify wheat leaf DNA, and the variety with the molecular marker detection result of claim 1 being the HEX genotype is selected.

10. A kit for identifying wheat fusarium head blight resistance gene Qfhb.jaas-6B, characterized in that: The kit contains the primer set according to claim 3.

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