Sources and genetic basis of variability of major and minor genes for yellow rust resistance in CIMMYT wheats
2000
Singh, R.P. (Centro Internacional de Mejoramiento de Maiz y Trigo (CIMMYT), Mexico, DF (Mexico)) | Huerta Espino, J. (Instituto Nacional de Investigaciones Forestales, Agricolas y Pecuarias. Chapingo, Mexico (Mexico). Campo Experimental Valle de Mexico)
Twenty-seven race-specific genes that confer resistance to yellow rust (Puccinia striiformis) have been catalogued so far. Of these genes, Yrl, Yr3, YrJ5, Yr17 and Yr27 have conferred high levels of resistance to some CIMMYT wheats either singly or in combination with Yr9 to current pathogen populations globally. We have detected the presence of additional, possibly new, genes in recent CIMMYT wheat lines. These major genes can be traced to the following sources: 'Bobwhite', 'Weaver', Chinese and synthetic wheats. The resistance gene from Bobwhite confers a seedling infection type ranging between 3 and 5 ( on a 0-9 scale) and is present in several advanced lines through the Bobwhite derived line 'Pastor'. Weaver's seedling resistance is associated with a gene that displays seedling infection types ranging from 4 to 6whereas seedling reactions of the Chinese and synthetic wheats derived advanced lines indicate that they may have contributed at least 4 new genes. A high degree of genetic diversity for additive, minor genes also exists in CIMMYT germplasm. Genetic analyses of wheat lines showing high levels of adult-plant resistance in evaluations conducted recently in Mexico, Ecuador, Kenya, Uganda and Iran indicate the presence of at least 4 to 5 additive, minor genes in each line. Utilization of resistance based on minor genes should lead to resistance durability .
显示更多 [+] 显示较少 [-]