Molecular marker closely linked with wheat Naxos sheath blight resistance gene Qse.jaas-5A, primer and application of molecular marker closely linked with wheat Naxos sheath blight resistance gene Qse.jaas-5A

Abstract

The invention discloses a molecular marker closely linked with a wheat Naxos sheath blight resistance gene Qse.jaas-5A, a primer and application, and belongs to the technical field of agricultural biology. According to the invention, disease-resistant wheat Naxos and susceptible wheat Soru # 1 are hybridized to construct an F6 family group, and a disease-resistant gene is positioned to a long arm 5A of a chromosome through resistance identification, a molecular marker technology and genetic map positioning and contributed by Naxos. In order to facilitate molecular marker-assisted selection of the disease-resistant gene, a KASP marker KASPIWA2641 closely linked with the gene is developed by utilizing a wheat 5A chromosome genome sequence and an SNP marker conversion method, and the marker can be used for high-throughput detection of the gene as a molecular marker of the sheath blight-resistant gene on a Naxos wheat 5A chromosome long arm, so that the marker can be used for detecting the sheath blight-resistant gene on the Naxos wheat 5A chromosome long arm. And auxiliary selection of a sheath blight resistant wheat variety carrying the gene is realized, so that the breeding process of a disease-resistant variety is accelerated.

Description

Technical Field

[0001] The invention relates to a molecular marker, a primer and an application thereof which are tightly linked to a wheat Naxos sheath blight resistance gene Qse.jaas-5A. The molecular marker can be applied to molecular marker-assisted breeding and belongs to the field of agricultural biotechnology. Background Art

[0002] Wheat sharp eyespot is a global soil-borne fungal disease of wheat caused by Rhizoctonia cerealis (Ren et al., 2020; Liu et al., 2021; Tomioka et al., 2021). As the world's largest endemic area (Wang et al., 2020), wheat production in my country is seriously affected by sheath blight. According to data from the National Agricultural Technology Extension Network (www.natesc.org.cn) (2011-2019), wheat sheath blight in my country is generally moderate or severe, with an average annual occurrence area of ​​about 130 million mu. It has become one of the main diseases affecting wheat production in my country, especially in the Huanghuai and middle and lower reaches of the Yangtze River. Sheath blight can cause rot at the base of wheat stems, reduce lodging resistance, and in severe cases, produce dead seedlings and dry white ears (Zhou Miaoping et al., 2017). Studies have shown that the disease rate of wheat sheath blight in the field is generally 10%-20%, and the rate in seriously diseased fields can reach 60%-80%, which can generally lead to a 10%-30% reduction in wheat yield, and even a 50% or more reduction in severe plots (Wang Jinfeng et al., 2012; Qi Yongxia et al., 2015). Since wheat sheath blight is a soil-borne disease, it is difficult to prevent and control it through agronomic cultivation measures, and chemical control is prone to cause environmental pollution. Therefore, studying the mechanism of wheat resistance to sheath blight, exploring and utilizing disease-resistant gene resources, and breeding and promoting disease-resistant varieties are the most economical and environmentally friendly measures to control the occurrence of the disease and reduce yield losses (Wu et al., 2017).

[0003] So far, many domestic research institutions have identified thousands of wheat germplasms for resistance to sheath blight. The results show that most germplasms are susceptible, there are few resistant germplasms, and no immune germplasm resources have been found. For example, Liu Ying et al. (2015) identified the resistance to sheath blight of 3,500 domestic and foreign wheat varieties, and only 32 materials reached the medium resistance level. It is generally believed that there are significant differences in sheath blight resistance among different wheat varieties. Most varieties are highly susceptible and susceptible, and a few varieties have good resistance, but there are no completely immune varieties (Zhang Huiyun et al., 2009, Li Hongjie et al., 2013); the sheath blight resistance of wheat varieties widely used in production and their core parents is generally poor (Wan Yingxiu et al., 2009; Jiang Yanjie et al., 2013; Zhou Miaoping et al., 2017). Since it is rare to find resources with good resistance to sheath blight in common wheat varieties, some scholars have turned to artificial wheat and wheat related species to look for disease-resistant germplasm. For example, Li Hongjie et al. (2013) identified the resistance to sheath blight of 56 wheat-Elytium wilfordii hybrids and found that the disease index of some germplasms was even lower than that of the resistant control varieties. Wei Xuening et al. (2015) identified the resistance to sheath blight of 102 artificial wheats from the International Maize and Wheat Improvement Center and found that compared with ordinary wheat varieties, most artificial wheats showed resistance or moderate resistance to sheath blight and could be used as a new source of resistance for breeding wheat resistant to sheath blight.

[0004] On the basis of a large number of screening of germplasm resources resistant to sheath blight, researchers actively used these resistant resources to conduct resistance gene mining research. Huo Naxin (2002) first used two RIL populations, Shanhongmai×Wenmai No. 6 and Opata×W7984, to locate three adult resistance QTLs on chromosomes 2B, 6B and 7B. Subsequently, many domestic units, including the applicant's research group, successively used genetic populations such as Chuan 35050×Shannong 483 (Zhang Xiaocun et al., 2005), ARz×Yangmai 158 (Cai Shibin et al., 2006), Luke×AQ24788-83 (Chen et al., 2013), and Niavt14×Xuzhou 25 (Jiang Yanjie et al., 2014) to locate QTLs related to sheath blight resistance on multiple chromosomes. However, since the main sources of molecular markers at that time were SSR, EST-SSR, etc., the number of polymorphic molecular markers obtained was limited, the density of genetic maps was generally low, and the distance between markers on both sides of the located QTL was large. With the application of SNP chip technology in wheat, commercial 90K, 55K, and 660K chips have facilitated the development of polymorphic SNP molecular markers. For example, Wu et al. (2017) used the wheat 90K SNP chip technology to construct the genetic map of the CI12633×Yangmai 9 RIL population, and detected a total of 5 QTLs for resistance to sheath blight on 2BS, 4BS, 5AL, and 5BS; Liu et al. (2021) used the wheat 55K SNP chip to encrypt the SSR map, which not only verified the results of previous studies, but also detected 3 new QTL loci.

[0005] Based on the current research results, wheat sheath blight resistance is a quantitative trait controlled by multiple gene loci and is easily affected by environmental factors. The repeatability of phenotypic identification in many studies is not high, and the confidence interval of the identified disease resistance gene loci is large. On the other hand, common wheat is an allohexaploid with a large and complex genome, which also poses a challenge for researchers to reveal the disease resistance mechanism. With the gradual expansion of sheath blight damage, the mining of sheath blight resistance genes and breeding research urgently need to be strengthened (Chen et al., 2013; Rong et al., 2016).

[0006] The traditional breeding method for disease-resistant varieties is to select disease-resistant plants after inoculation and identification. This method sometimes affects the selection efficiency due to insufficient inoculation or unsuitable disease conditions. With the emergence and continuous development of molecular marker technology, molecular markers can be used to identify and select disease-resistant genes, thus developing the molecular marker-assisted selection (MAS) method. The use of molecular markers to detect disease-resistant genes allows selection in early generations, improves the accuracy of selection, reduces the breeding population, and is not restricted by the environment and growing season. Combined with the generation-adding technology, it can greatly shorten the breeding period and improve the breeding efficiency. Therefore, molecular marker technology has become an important means of assisted breeding. However, there are currently few research results on molecular markers that are stable in resistance and closely linked to the sheath blight resistance gene. There is an urgent need to provide a new and stable molecular marker that is closely linked to the sheath blight resistance gene. Summary of the invention

[0007] In order to solve the above technical problems, the present invention provides a molecular marker, primer and application thereof tightly linked to the wheat Naxos sheath blight resistance gene Qse.jaas-5A, and uses the sheath blight-resistant wheat variety Naxos as a disease-resistant material to screen and find new and stable molecular markers tightly linked to the sheath blight resistance gene and a method thereof for use in wheat sheath blight assisted selection breeding, which can overcome the shortcomings of conventional genetic breeding such as a long cycle.

[0008] The technical solution provided by the present invention is as follows:

[0009] A molecular marker tightly linked to the wheat Naxos sheath blight resistance gene Qse.jaas-5A, the molecular marker is located on the long arm of wheat chromosome 5A, for wheat susceptible to sheath blight, the 708440998th nucleotide of chromosome 5A is T, and its nucleotide sequence is shown in SEQ ID No.1; for wheat resistant to sheath blight, the 708440998th nucleotide of chromosome 5A is C, and its nucleotide sequence is shown in SEQ ID No.2.

[0010] The present invention also provides the above-mentioned primers for the molecular markers tightly linked to the wheat Naxos sheath blight resistance gene Qse.jaas-5A, the nucleotide sequence of the primers is as follows:

[0011] Forward primer 1: FAM-5′-acaggtttgGaAggtgaacatT-3′;

[0012] Forward primer 2: HEX-5′-acaggtttgGaAggtgaacatC-3′;

[0013] The rear primer was 5′-ccagagCagactcctcAtacaA-3′.

[0014] The present invention also provides the use of the molecular markers tightly linked to the wheat Naxos sheath blight resistance gene Qse.jaas-5A or the primers in identifying wheat sheath blight resistance.

[0015] The present invention also provides the use of the molecular marker tightly linked to the wheat Naxos sheath blight resistance gene Qse.jaas-5A or the primer in breeding wheat with sheath blight resistance.

[0016] The present invention also provides a method for identifying wheat resistance to sheath blight, which detects whether a wheat DNA sample carries the wheat sheath blight resistance gene Qse.jaas-5A. If it carries the gene, it indicates that the wheat to be tested has higher resistance to sheath blight.

[0017] Furthermore, the obtained amplified product was subjected to fluorescence signal scanning, and the scanning data was analyzed to obtain a scatter plot. When the genotype appeared in the X-axis area in the scatter plot, it indicated that the wheat was a FAM genotype variety and had a low resistance to wheat stripe blight; when the genotype appeared in the Y-axis area, it indicated that the wheat was a HEX genotype variety and had a high resistance to wheat stripe blight.

[0018] The present invention also provides a method for breeding wheat carrying the sheath blight resistance gene Qse.jaas-5A, using the above primers to PCR amplify wheat leaf DNA, and selecting varieties with the above molecular marker detection results as HEX genotypes.

[0019] The primers are primers of a KASP marker KASP_IWA2641 which is closely linked to the wheat Naxos sheath blight resistance gene Qse.jaas-5A, and the genetic distance between the marker KASP_IWA2641 and the target gene is less than 0.4 cM.

[0020] Furthermore, the reaction system of PCR amplification is:

[0021] Template (~20ng / μl) 2.5μl, KASP assay mix 0.07μl, 2×KASP master mix 2.5μl; the KASP assay mix (100μl) includes: 12μl (100μM) of each allele-specific forward primer, 30μl (100μM) of the rear primer and 46μl of Tris-HCl (10mM, PH 8.3).

[0022] 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 (0.8°C decrease per cycle)”; and finally 32 cycles of amplification at “94°C, 20 s; 57°C, 60 s”.

[0023] Fluorescence analysis of PCR products was performed using the PHERAstar (LGC Genomics) instrument, and finally typing was performed using the KlusterCaller (LGC Genomics) software.

[0024] The invention also provides a detection kit for identifying the wheat sheath blight resistance gene Qse.jaas-5A, wherein the detection kit contains the above primers.

[0025] The molecular marker primers are used to PCR amplify wheat plant DNA using the primers of the KASP marker KASP_IWA2641 that is tightly linked to the wheat sheath blight resistance gene Qse.jaas-5A. If the HEX genotype of the KASP_IWA2641 marker (the same as Naxos) appears, it indicates that the wheat sheath blight resistance gene exists in the plant. The application is to amplify wheat plant DNA with Soru#1, Naxos and their recombinant inbred lines as the objects.

[0026] Beneficial Effects

[0027] Sheath blight is a serious disease that affects wheat production. The present invention has carried out multi-year multi-point identification of sheath blight resistance on newly collected domestic and foreign wheat resources, screened out the disease-resistant wheat variety Naxos from Germany from thousands of materials, and used the Soru#1×Naxos recombinant inbred line population introduced from the International Maize and Wheat Improvement Center (CIMMYT) to carry out sheath blight resistance identification and disease resistance QTL positioning in multiple environments for 5 consecutive years, and repeatedly detected a stable QTL site Qse.jaas-5A in the marker interval Ex_c27357_146-wExc2171_4072774 on the long arm of chromosome 5A. The genetic distance of this interval is 0.4cM, and the corresponding physical segment of Chinese Spring 5A chromosome is 10.2Mb. Qse.jaas-5A can be repeatedly detected in all environments, and the phenotypic contribution rate is as high as 22.74%. The correlation analysis with heading date and plant height showed that the correlation between Qse.jaas-5A and heading date and plant height was not significant, indicating that the sheath blight resistance controlled by this locus is not easily affected by heading date and plant height, and is easy to use in breeding. It has important value in wheat breeding practice and disease resistance theory research. Its advantages can be summarized as follows:

[0028] (1) The KASP marker tightly linked to the wheat sheath blight resistance gene Qse.jaas-5A in the present invention is a new marker obtained in a hybrid progeny plant with stable resistance to the wheat variety Naxos and its hybrid progeny, and is stable and can be used for identification of wheat sheath blight varieties and auxiliary selection breeding of wheat disease-resistant progeny.

[0029] (2) The material Naxos used in this study is a new source of resistance to sheath blight. Based on this molecular marker, it is expected that new sheath blight resistance genes will be discovered.

[0030] (3) The marker is a stable KASP marker, which is closely linked to the sheath blight resistance gene, with a genetic distance of <0.4 cM. It can be directly used for molecular marker-assisted selection breeding of wheat sheath blight resistance to accelerate the breeding process. At the same time, it lays a good foundation for cloning new wheat sheath blight resistance genes and studying their functions. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] The above and other objects, features and other advantages of the present invention will be more clearly understood through the following detailed description in conjunction with the accompanying drawings, in which:

[0032] Figure 1 The segregation of KASP_IWA2641 marker on chromosome 5A in the parent and the recombinant inbred line progeny, wherein the HEX genotype indicates the presence of the sheath blight resistance allele in the plant.

[0033] Figure 2 The genetic linkage and physical map of Qse.jaas-5A, in which KASP_IWA2641 (wExc2171_4072774) is tightly linked to Qse.jaas-5A.

[0034] Figure 3 The results of identification of KASP marker KASP_IWA2641 in 215 wheat germplasm resources at home and abroad. Among them, the HEX genotype indicates the presence of sheath blight resistance alleles in the sample.

[0035] Figure 4 This paper compares the resistance of FAM and HEX genotypes to sheath blight among 215 wheat germplasm resources from home and abroad. DETAILED DESCRIPTION

[0036] The methods used in the following examples are all conventional methods unless otherwise specified.

[0037] Example 1. Acquisition of molecular markers linked to the wheat Naxos sheath blight resistance gene

[0038] 1. Plant materials

[0039] Soru#1 (SABUF / 5 / BCN / 4 / RABI / / GS / CRA / 3 / AE.SQUARROSA(190)) and Naxos (Tordo / St.Mir808-Bastion / / Miranet) are resistant to sheath blight, both of which were preserved and provided by the wheat germplasm resources innovation team of the Institute of Germplasm Resources and Biotechnology, Jiangsu Academy of Agricultural Sciences. Soru#1 and Naxos were used as hybrid combinations to construct recombinant inbred line populations.

[0040] 2. Evaluation method of resistance to sheath blight

[0041] In a plant growth room with controllable environmental conditions such as temperature and humidity, the diseased wheat kernel inoculation method was used to identify the resistance to sheath blight. The specific method is as follows: During the wheat jointing stage, the cultivated wheat kernels full of R0301 sheath blight fungi were inoculated on the soil surface, close to the base of the wheat stems. After inoculation, the soil was covered and kept moist until the disease was completely cured. During the milky stage, the incidence of sheath blight on the inoculated stems was investigated according to the 0-5 grade grading standard:

[0042] Level 0: The whole plant is disease-free;

[0043] Level 1: The leaf sheaths have typical sheath blight lesions, but the stems are not invaded;

[0044] Level 2: The pathogen invades the stem, and the width of the lesion around the stem does not exceed 1 / 4 of the circumference of the stem;

[0045] Level 3: The pathogen has invaded the stem, and the width of the lesion ring on the stem is between 1 / 4 and 1 / 2 of the stem circumference;

[0046] Level 4: The pathogen invades the stem, and the lesions on the stem cover 1 / 2 to 3 / 4 of the stem;

[0047] Level 5: The pathogen invades the stems, and the lesions on the stems surround more than 3 / 4 of the stems, or the stems become soft rotted, or the ears become dry or white.

[0048] The disease index (DI) was calculated using the following formula:

[0049]

[0050] In the formula, i is a certain disease level, x i is the number of stems with the disease level, and N is the total number of stems investigated.

[0051] 3. Marker analysis

[0052] The genomic DNA extraction method was based on the CTAB extraction method of Dreisigacker et al. (2016) to extract total DNA from young leaves. The PCR reaction was performed on a ThermoFisher thermal cycler. The reaction system was 5 μL, containing 2.5 μL of 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 mastermix from LGC Genomics. 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 per cycle)"; and 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.

[0053] 4. Tag development

[0054] Sequences obtained based on 90K SNP chip sequencing: This study used the Soru#1×Naxos F6 generation recombinant inbred line (RIL) population as the material, and constructed a high-density genetic map using SNP markers obtained by the wheat 90K SNP chip analysis method. A new locus with a large and stable effect on resistance to sheath blight was located on the long arm of chromosome 5A, named Qse.jaas-5A, and the SNP markers on both sides of the locus were converted into KASP markers. Since the sequence obtained by SNP chip sequencing is short, this study used the sequence to search and compare the reference genome sequence of common wheat Chinese Spring (IWGSC RefSeq v2.1) to obtain a long sequence fragment containing the SNP site, and used the software Primer 6.0 to convert the tightly linked SNP markers into KASP markers. The designed KASP marker can detect polymorphisms between the two parents and can be relocated to the genetic map of Qse.jaas-5A ( Figure 2 ; Table 1).

[0055] The information of the newly developed markers is shown in Table 1, and the primer sequences used to amplify the molecular markers are shown in Table 2.

[0056]

[0057]

[0058] Table 2 Primer sequences used to amplify the molecular markers

[0059]

[0060] Example 2: Application of molecular marker KASP_IWA2641 in detecting genes for resistance to sheath blight

[0061] In order to verify the feasibility of KASP_IWA2641 marker in detecting wheat sheath blight resistance genes, this example uses KASP_IWA2641 marker to detect Soru#1×Naxos recombinant inbred line population, and obtains fluorescence scanning results by reading the fluorescence signal of KASP marker amplification products. Kluster Caller software is used to analyze the scanning data. 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 1 ).

[0062] 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.

[0063] The results showed that the genotype obtained by using the KASP_IWA2641 marker was completely consistent with the original 90K chip results. This result shows that the KASP_IWA2641 marker can be used to detect the wheat sheath blight resistance gene Qse.jaas-5A and be applied to molecular marker-assisted breeding of wheat sheath blight resistance in my country.

[0064] Example 3: Application of molecular marker KASP_IWA2641 in screening of wheat germplasm resources resistant to sheath blight

[0065] In order to verify the application of KASP_IWA2641 marker in the screening of wheat germplasm resources resistant to sheath blight, and whether it can be used for genetic improvement of wheat varieties resistant to sheath blight in my country, this example uses KASP_IWA2641 marker to detect 215 wheat germplasm resources from different sources, 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 (low resistance to wheat sheath blight), and the varieties in the Y-axis area are "HEX" genotypes (high resistance to wheat sheath blight) ( Figure 3 ).

[0066] 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.

[0067] The results showed that the genotyping of 215 wheat germplasms from different sources was divided into two groups using KASP_IWA2641 marker. Among them, 203 germplasms (94.4%) such as rapeseed yellow and red scorpion were of "FAM" type, and 12 germplasms (5.6%) such as Jagger and Tyalt were of "HEX" type ( Figure 3 ). The "HEX" type, which represents the disease resistance gene Qse.jaas-5A, only accounts for 5.6% of the total, indicating that most wheat germplasm resources lack the resistance gene Qse.jaas-5A to sheath blight. The results of the field identification of sheath blight resistance of the above 215 wheat germplasm resources were statistically analyzed. The results showed that the average sheath blight disease index of varieties containing the Qse.jaas-5A gene was 38.18%, while the average sheath blight disease index of varieties without the Qse.jaas-5A gene was 42.69%. The difference in sheath blight resistance between the two reached an extremely significant level ( Figure 4). This result indicated that the KASP_IWA2641 marker could be used for the detection of wheat sheath blight resistance gene Qse.jaas-5A and its molecular marker-assisted breeding.

Claims

1. A molecular marker tightly linked to the wheat Naxos sheath blight resistance gene Qse.jaas-5A, characterized in that: The molecular marker is located on the long arm of wheat chromosome 5A. For wheat susceptible to sheath blight, the 708440998th nucleotide of chromosome 5A is T, and its nucleotide sequence is shown in SEQ ID No.1; for wheat resistant to sheath blight, the 708440998th nucleotide of chromosome 5A is C, and its nucleotide sequence is shown in SEQ ID No.

2.

2. The primers for molecular markers tightly linked to the wheat Naxos sheath blight resistance gene Qse.jaas-5A according to claim 1, characterized in that: The nucleotide sequences of the primers are as follows: Forward primer 1: FAM-5′-acaggtttgGaAggtgaacatT-3′; Forward primer 2: HEX-5′-acaggtttgGaAggtgaacatC-3′; The rear primer was 5′-ccagagCagactcctcAtacaA-3′.

3. Use of the molecular marker tightly linked to the wheat Naxos sheath blight resistance gene Qse.jaas-5A as claimed in claim 1 or the primer as claimed in claim 2 in identifying wheat sheath blight resistance.

4. Use of the molecular marker tightly linked to the wheat Naxos sheath blight resistance gene Qse.jaas-5A as claimed in claim 1 or the primer as claimed in claim 2 in breeding wheat with sheath blight resistance.

5. A method for identifying wheat resistance to sheath blight, characterized in that: Detect whether the wheat DNA sample to be tested carries the wheat sheath blight resistance gene Qse.jaas-5A. If it does, it indicates that the wheat to be tested has a higher resistance to sheath blight.

6. The method for identifying wheat resistance to sheath blight according to claim 5, characterized in that: 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 has a low resistance to wheat sheath blight; when the genotype appears in the Y-axis area, it indicates that the wheat is a HEX genotype variety and has a high resistance to wheat sheath blight.

7. The method for identifying wheat resistance to sheath blight according to claim 5, characterized in that: The reaction system for PCR amplification is: 2.5 μl of template, 0.07 μl of KASP assay mix, and 2.5 μl of 2×KASP master mix; the KASP assay mix includes: 12 μl of each allele-specific forward primer, 30 μl of rear primer, and 46 μl of Tris-HCl.

8. The method for identifying wheat resistance to sheath blight according to claim 5, characterized in that: 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 sheath blight resistance gene Qse.jaas-5A, characterized in that: The primers described in claim 2 are used to PCR amplify wheat leaf DNA, and the varieties whose molecular marker detection results according to claim 1 are HEX genotypes are selected.

10. A kit for identifying wheat sheath blight resistance gene Qse.jaas-5A, characterized in that: The kit contains the primers according to claim 2.

Images