Qtls Mapping For Resistance To Sharp Eyespot By Using A Recombinant Inbred Lines Population Derived From The Cross Between Niavt14and Xuzhou25in Wheat

Sharp eyespot is a fungal disease caused by Rhizoctonia cerealis or Rhizoctonia solani. With the changes in agronomic practices and global warming up climate, wheat sharp eyespot has become more and more severe in the Middle and Low Yangtze River Region and Huang-huai Winter Wheat Region in recent years. It has become one of the most important wheat diseases in China. The characterization and utilization of new genetic resources with sharp eyespot resistance will undoubtedly become an important way to control the wheat sharp eyespot.114accessions of wheat germplasm were re-evaluated for resistance to wheat sharp eyespot after artificial inoculation with fungi culture R0301in field conditions in2continous yeas of2010and2011. The results conformed that most accessions were stable resistance to the disease.34accessions, such as Niavtl4and Xinmai26were resistance to the disease.49accessions, such as Xinong88and Tyalt were moderate resistance to the disease. Among the resistant accessions.15were introduced from abroad.7were landraces and12were improved cultivars or lines. They could be used in genetic study and breeding program for resistance to sharp eyespot.The RILs population was developed with215lines from the cross between Niavt14and Xuzhou25by using SSD method. Niavt14was resistant parent, Xuzhou25was susceptible parent. The215RILs and their parents were inoculated in field trial in2009-2011and in greenhouse in2011using toothpick inoculation method. The results showed that the phenotyping data generally met the requirement to perform the mapping of QTLs. Five hundred and three pairs of SSR primers were surveyed for polymorphism between the parents, and177primers showed polymorphic in the population.41linkage groups were established using JoinMap3.0softwar. The total length of the linkage map was 884.4cM. The average interval was6.0cM. Three chromosome regions were detected for their association with the resistance through composite interval mapping (CIM, Windows QTL Cartographer).2resistance QTLs(LOD>3.0) to sharp eyespot in wheat were detected on2B chromosome, Qses.jaas-2bl was detected in field in2009and2010, could explain5.46%and8.56%of the phenotypic variance, respectively; Qses.jaas-2b2was detected in three continous years from2009to2011, and could explain6.04%、8.10%and12.92%of the phenotypic variance, respectively. Qses.jaas-7d on7D chromosome was detected both in field test in2009and in greenhouse test in2011, it could explain11.25%and6.84%of the phenotypic variance, respectively. We consider the major QTLs resistant to wheat sharp eyespot were located on2B and7D chromosomes and all of them were from the resistant parent Niavt14.Meanwhile, location of QTLs for plant height, heading date and flowering date in this RIL population were also studied. Results indicated that one QTL on2B chromosomes for heading date was different from the QTL for sharp eyespot resistance. Although the intervals of the QTLs for plant height, heading date and flowering date on chromosome7D were similar to the QTL for sharp eyespot resistance, they were different from the reported ones. Therefore, wheather sharp eyespot resistance on chromosome7D has some associations with plant height, heading date and flowering date need to be verified.