Genetics Analysis Against The Wheat Stripe Rust And RAPD Marker Study On The Important Cultivars

Wheat stripe rust (yellow rust), caused by Puccinia striiformis West. f. sp. tritici, is one of the most important diseases on wheat throughout the world. It is an effective way to use resistant cultivars conferring major resistance genes by maker-assisted selection, which would accelerate breeding program.There are two parts in this study , the firsrt part is genetic analysis of resistance to stripe rust in the varieties of Honggeda and Hongmai ,the other part is RAPD analysis between DNA pool and Yuzicao carrying the resistance gene against wheat stripe rust and its susceptible parent Avocet S1. Genetic analysis was carried out for (to get the information of the) resistance to stripe rust in the varieties Honggeda and Hongmai. The two varieties, as the male parents, were crossed respectively with the susceptible cultivar Mingxian 169. The F₁ progeny were self-fertilized to produce the F₂ progeny and . meanwhile . they were backcrossed with Mingxian 169 to produce BC₁ progeny. According to the resistance phenotypes of the parents, F₁, F₂ and BC₁ progeny to the tested races of stripe rust, the resistance of Honggeda to the race CY19 was controlled by recessive epigyny action of the one dominant gene and two recessive genes, to the race CY26 was controlled by recessive epigyny action of the one dominant gene and two recessive genes, and to the race CY32 was controlled by complementary action of the three recessive genes. The resistance of Hongmai to the race CY19 was controlled by repetitive or complementary action of the two dominant genes , to the race CY26 was controlled by one incomplete dominant genes , to the race CY29 was controlled by complementary action of two dominant genes, to the race CY31 was controlled by complementary action of two dominant genes and one recessive gene, to the race CY32 was controlled by dominant epigyny action of the one dominant gene and two recessive genes.2. The segregation of resistance gene was evaluated respectively by CY30, Hy-â…¢ artificial infection of F₂ plants from the cross Mingxian169×Yuanzicao.With the genetic analysis of these segregations, the combination above could be used for bulked segregation analysis (BSA).Using the resistance gene donor parent Yuzicao and Mingxianl69 as contrast, with the contrast of yuzicao , which is the donor of the resistance gene, and Mingxianl69, the RAPD were used to analyze the DNA pool. Amplified DNA fragments were separated with 4% denaturing PAGE (polyacrylamide gel electrophoresis) and displayed by silver staining. Fifty to one hundred bands were detected, 5 folds more than that revealed on agarose gels. A total of 200 random primers were screened200 random primers were screened totally, and 9 reproducible polymorphic DNA fragments of them were foundo In 9 polymorphic DNA fragments, the fragment OPR9872 derived from 9 primers, were confirmed to be linked to the resistance gene of Yuanzicao by preliminary genetic linkage analysis. The fragments OPR9g72 linked to the target gene, were recovered cut from polyacrylamide gel and cloned in pGEM-T easy vector, then sequenced according to the result of sequencing, four pairs of specific primers were designed. Genetic linkage between the PCR products and the target gene was tested on 220 segregating F2 plants derived from a cross between Mingxian 169 and Yuanzicao. In the result .the SCAR markers was failed, the result with RAPD analysis showed that the crossing was about 32.27%O...