Identification Of Resistance To Barley Yellow Mosaic Virus And Mapping Of Relevant QTLs

The soil-borne barley yellow mosaic disease (BYMD) is infected by two different bymoviruses, barley mild mosaic virus (BaMMV) and barley yellow mosaic virus (BaYMV). Both are transmitted by the soil-borne fungus Polymyxa graminis Led. Barley yellow mosaic disease is one of the main diseases in Asia and Europe winter barley growing area, which reduced the yield and grain quality. Exploring and breeding new resistant germplasm resources is the most effective approach to maintain the sustainable development of the barley production against barley yellow mosaic disease.A total of 188 doubled-haploid (DH) lines derived from a cross between a Chinese barley landrace-TX9425 and a Japanese beer barley variety-Naso Nijo were used to estimate the resistance to barley yellow mosaic disease. High-dedsity molecular genetic map consisting of DArT and SSR molecular markers was used to identify QTLs associated with the resistance to BaYMV/BaMMV. Following are the main results:1. In two years, TX9425 was significantly resistant to BYMD than Naso Nijo.188 DH lines were clustered into R, MR, MS and S four resistance levels.13 lines showed stable resistance,38 lines showed stable moderately resistant,22 DH lines performance moderately susceptible and 15 DH lines performance susceptible.2. As a result of ANOVA, in 2013, barley yellow Mosaic significantly affected plant height, spike internode length and yield. The differences of character between disease resistance (R) and disease resistance (MR) were not remarkable. But variance was obvious between disease resistance (R) and disease resistance (MS), disease resistance (S). In 2014, barley yellow mosaic rather meaningfully changes plant height, spike internode length, even the yield of plant height, thousand-grain weight main panicle grain yield per plant, ear number per plant. Distinction between disease resistance (R) in the various characters and disease resistance (MR) is not quite distinct, but comparison with disease (MS) and disease (S) was significant different in various characters, decline for the middle sense (MS) and sense of disease (S) of plant yield by 6.56% and 23.51% respectively. After the path analysis of agronomic traits and resistant index AUDPS size to the yield per plant, the results showed barley yellow mosaic disease mainly controlled the plant height, ear number per plant to reduce the yield of per plant.3. With Area under Disease Progress Stairs, AUDPS and Disease Index as phenotypic resistance, eight QTL for resistance to barley yellow mosaic disease were identified using composite interval mapping method in two years. Among these QTLs, four QTLs, Qymv-1Hα、 Qymv-3H、 Qymv-7Hα and Oymv-7Hb, were linked to both AUDPS and DI, which explained the phenotypic variation of 3.40%～7.19%,9.69%～18.68% and 9.69%～15.90% and 3.98%～ 25.78%, respectively. Resistance of TX9425 was controlled by multiple loci and the sensitive parent Naso Nijo also exists in the barley yellow Mosaic disease resistance QTL.