Resistance Evaluation Of 53 New Wheat Varieties(Lines) And Genetic Analysis Of Powdery Mildew Resistance Gene Of Fengyou No.8

Wheat(Triticuma aestivum L.) is one of the most important food crops in the world after corn and rice, and wheat diseases seriously endanger the production of wheat. The most economical, safe and effective measure to control the epidemic of wheat diseases is to cultivate and improve the disease resistant varieties.Mining resistant gene resources is the material basis for breeding disease resistant varieties.Therefore, the discovery of new resistant materials and the discovery of new resistance genes are ongoing and important tasks in disease resistance breeding. In the study. The adult resitance to stripe rust and powdery mildew of 53 new varieties(lines) were identified and genetic analysis of powdery mildew resistance of wheat variety Fengyou No. 8 was done.The main results were shown as follows:(1)Stripe rust and powdery mildew resistance Identification of 53 new varieties(lines) at the adult stageAfter inoculated Pst(Puccinia striiformis f. sp. tritici) races CYR32 and CYR33 at the adult stage,the identification results indicated that13 of them showed highly resistance to Pst with IT(infection type)of 0~1, including Zhenmai 1, Zheng 132, shaanmai 139, Zhengmai 369, Lankao 165, Fu 0608, Dunfeng 802, Xinkemai 169, Xianmai 12, Pumai 6311, Bainong 121, Zhoumai 32 and Fengyou No.8, and 16 of them showed moderately resistancewith IT of 2,including Zhong 013, Pingxuan No.10, Zhaofeng 295, Jiuyuan 768, Zhongmai 69, Junxiao 22, Jinyan No.1, Fengmai 716, Bainong 416, Yan 1212, Xumai 262, Anmai 1126, Zhongguanmai No.1, Yumai 605, Lunxuan 136 and Jiuyuan 658, and the remaining 24 materials were susceptiblewith IT of 3~4.After inoculated the mixed strains of Bgt(Blumeria graminis f. sp. tritici) of Guanzhong area of Shaanxi Province at the adult stage,Identification results indicated that that16 of them showed highly resistance to Bgt with a score of 0~2, including Bainong 121, Shengnong 1, Haomai 18, Fengyou No.8, Zhengmai 131, Zhaofeng 295, Bainong 416, Zhengmai 369, Xumai 262, Bainong 201, Fu 0608, Pingxuan No.10, Xianmai 12, Lankao 165, Zheng 132 and Yumai 605, and 10 of them showed moderately resistance with a score of 3-4, including Junmai 21, Yumai 801, Jindan 6338, Yumai 601, Zhengmai 618, Lunxuan 33, Womai 021001-8, Jiuyuan 658 and Shaanmai 139, and The remaining 27 materials were all Susceptible with a score of 5-8. Among them, there are seven material showed good resistance to Bgt and Pst, included Bainong 201, Fengyo No. 8, Zhengmai 369, Fu 0608, Xianmai 12, Lankao 165 and Zheng 132.Thus, this reserch provided resistance materials for wheat resistance breeding.(2)Genetic analysis of powdery mildew resistance of Fengyou No. 8Inoculated with Bgt race E09 at the seedling stage and the mixed Bgt strains of Guanzhong area of Shaanxi Province at adult stage, identification results showed that Fengyou No.8 and the F1 generation of Fengyou No. 8 and Shaanyou 225 showed highly resistance. At the seedling stage, the F2 generation of Fengyou No. 8 and Shaanyou 225 were inoculated with Bgt race E09. In the 118 of F2 plants, 93 plants showed highly resistance and 19 plants showed susceptible. After the χ2 test, the results fitted the ratio of 3:1(χ3:1=3.48<χ20.05,1=3.84,df=1). This indicated that the powdery mildew resistance of Fengyou No. 8 is controlled by a single dominant gene.Using SSR marker and bulked segregant analysis(BSA), we selected 719 g SSR markers and 60 EST-SSR markers to test the genetic polymorphism of the parents, resistance bulk and suscetiple bulk, and F2 generation. We obtained two molecular markers-Xbarc183 and SWES231, which linked to the powdery mildew resistance gene of Fengyou No.8. The specific bands of Xbarc183 and SWES231 were 125 bp and 550 bp, respectively. Based on the results of http://wheat.pw.usda.gov, Xbarc183 is located on the chromosome of 2B and 6D, and SWES231 is located on the chromosome of 6D and 6A. Therefore, we hypothesized that the powdery mildew resistance gene of Fengyou No.8 was located on wheat chromosome 6D, temporarily named as Pmfy8.It laid the foundation for the application of the powdery mildew resistance gene of Fengyou No.8 in wheat breeding for disease resistance.