Genetic Analysis Of H9020-17-25-6-4 And Tian867 For Resistance To Strip Rust

Wheat strip rust, caused by Puccinia striiformis f.sp. tritici, is a destructive disease worldwide. Epidemic from the country`s wheat planting area in China has occured for several times. Resistance genes to strip rust from common wheats are in the danger of losing resistance after years` time in use. Current dominant races of PST have overcomed the most resistance genes. A new way to control this worldwide disease is to introduce foreign genes into common wheats. Such kind of reserch has already taken part in the breeding work and the importance seems to increase. The latest molecular markers can be as a useful tool to identify genes derived from related plant of wheat and the marker-assistant selection(MAS) were used for wheat disease resistance breeding .In this paper, a translocation line named H9020-17-25-6-4, bred by means of embryo culture after crossing Psathyrostachys huashanica Keng with 7182, was tested by current 7 dominant races. The results are as follow:1. Translocation line H9020-17-25-6-4 has resistance to current dominant PST races Sun11-4, Sun11-11, CYR29, CYR30, CYR31, CYR32 and CYR33 of Chinese yellow rust. It can be used as a resistance resource in breeding.2. H9020-17-25-6-4 resistance to CYR29 was controlled by a dominant gene temporarily named YrH-1. Ten linkage markers were found flanking to this gene. Seven SSR markers and three RGAP markers associated with nulli-tetrasomic analysis located this gene to 3AS.The nearest flanking markers to this gene were cfd79 and M1 with a genetic distance of 7.2 and 6.9cM. Pedigree analysis shows YrH-1 is a new gene derived from Psathyrostachys huashanica Keng.3. Flanking markers cfd79 and xgwm2 were used in testing current dominant planting wheat cultivars of huang-huai area and isogene lines. Three huang-huai cultivars and 2 isgenetic lines have the same amplification fragments to translocation line H9020-17-25-6-4.And in this paper, a genetic analysis was undergoing to identify the resistance genes in Tian867. The results are as follow:1. Resitance of Tian867 to seven dominant CYR races was different. Tian867 was susceptible to CYR32 and resistant to other six races. The resistance was controlled by one or two genes.2. Resistance to Su11 was controlled by a dominant gene. Further works of molecular mapping can be done in the next step to make the usage of this gene in MAS more easier.