Genetic Analysis And Genetic Linkage Mapping Based On RGAP Marker Of Stripe Rust Resistance Gene In Roegneria Kamoji

Roegneria kamoji Keng (2n=6x=42, StStYYHH) is a perennial species in the genus Roegneria C. Koch. R. kamoji is an excellent resource of wild grass, which has thick stem, wide leaves, and high resistance to scab. The excellent genes in R. kamoji could be used in wheat breeding by hybridization and the modern biological technology.Different R. kamoji varieties showed different resistance to stripe rust in the field. The cultivated variety R. kamoji Gansi No.1 is highly susceptive to the stripe rust, while R. kamoji cv. Dujiangyan is immune to the stripe rust. In order to investigate the stripe rust resistance gene in R. kamoji, hybridizations were carried out between R. kamoji Gansi No. 1 and R. kamoji cv. Dujiangyan. The resistance to stripe rust was observed in the F2 populations of R. kamoji Gansi No.1 x R. kamoji cv. Dujiangyan. Resistance gene analog polymorphism (RGAP) markers were used in this study for searching the molecular markers which linked to the stripe rust resistance gene in R. kamoji. The main results are as follows:1. In the seeding tests of parents, R. kamoji cv. Dujiangyan was resistance to the mixed races (Tiao zhong 31,32,33, Sull-4, Sull-5 and CH42) of Puccinia striiformis f. sp. tritici, while R. kamoji Gansi No.1 was susceptible to the mixed races. Seedlings of the F1, F2 populations of R. kamoji Gansi No.1 x R. kamoji cv. Dujiangyan were also tested with the mixed races. In 2011-2012 field tests, The fifty F1 plants of R. kamoji Gansi No.1 x R. kamoji cv. Dujiangyan at most of stages scored IT 0, indicating that adult-plant resistance of R. kamoji cv. Dujiangyan was conferred by dominant gene(s). In 2013, the F2 population segregated as 142 resistance (IT 0-2),58 susceptible, which fitted 3:1 resistance: susceptible segregation ratio (χ3xl2=1.5, P>0.05). The genetic analysis showed that resistance to stripe rust in R. kamoji cv. Dujiangyan was controlled by a single dominant gene, which temporarily designated as Yr1007.2. RGAP markers combined with bulked segregation analysis (BSA) revealed that three RGAP markers (Ml, M2, M3) were linked to Yr1007. The genetic distance of three markers to Yr1007 was 27.7cM,11.6cM,38.3cM, respectively.