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Genetic Analysis of Four Wheat Cultivars (Lines) and Molecular Mapping of Stripe Rust Resistance Gene in Mega

Author: LiYang
Tutor: JingJinXue
School: Northwest University of Science and Technology
Course: Plant Pathology
Keywords: Stripe rust Wheat cultiva(rZhongliang21、93444、93445) Triticum-Leymus mollis translocation line Genetic analysis SSR
CLC: S512.1
Type: Master's thesis
Year: 2009
Downloads: 54
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Abstract

Wheat stripe rust, caused by Puccinia striiformis f.sp. tritici is one of the most important wheat diseases in the worldwide, especially in China. The most economical, effective, feasible and environment friendly methods to control this disease are planting resistant cultivars. But high genetic variation and the ability of the pathogen to evolve into new races with added new virulence always have been the major limiting factors in a successful long-term management of stripe rust when race-specific resistance genes are used. So, the key to solve the problem of wheat varieties resistant loss to stripe rust is to find and use of high-quality resistance source of new wheat varieties.In the research, the genetic analysis of resistance genes to stripe rust in three Chinese cultivars and a Triticum–Leymus mollis translocation line have been done and SSR markers of one stripe rust resistence gene in wheat cultivar Mega was investigated.The results are as follows:1.Using the current epidemic yellow rust races CYR29,CYR30,CYR31,CYR32, CYR33, Su-4 and Su-11inoculated to three Chinese cultivars(Zhongliang21、93444、93445) and a Triticum-Leymus mollis translocation line (M8725-2)for resistance evaluation. The results showed the three Chinese cultivars and the Triticum -Leymus mollis translocation have effective resistance to the dominant races in China.2. It showed by genetic analysis of three Chinese cultivars and the Triticum-Leymus mollis translocation line resistance to stripe rusts that:(1)Single dominant gene confer resistance to CYR30, one dominant gene and two recessive genes to CYR31 ,two dominant genes and one recessive gene to CYR32, two dominant genes to Su-4 in Zhongliang21.(2)One dominant gene and one recessive gene confer resistance to CYR29 and CYR32, two dominant genes and one recessive gene to CYR30, one dominant gene and two recessive genes to CYR31 and Su-4 in 93444.(3)Single dominant gene confers resistance to CYR29, One dominant gene and one recessive gene to CYR30, two dominant genes to CYR31 in 93445.(4)One dominant gene and one recessive gene confer resistance to CYR30 and CYR32; two recessive genes to CYR31 in M8725-2.3. Mega, one of the European wheat cultivar, has effective resistance to the dominant races(CYR30、CYR31、CYR32、Su-4 and CYR33) of Puccinia striiformis f . sp. tritici in China, in seeding stage. Simple sequence repeat (SSR) techniques were used to develop molecular markers linked to the resistance gene in wheat cultivar Mega. 237 pairs of wheat SSR primers were used to test the two parents, as well as resistant and susceptible bulks. Subsequently, 2SSR markers were employed for genotyping the F2 population. The result indicated that the stripe rust resistance in cultivar Mega to CYR30 was conferred by a single dominant gene, temporarily designated as YrMe, located closely to the chromosome 5BL and flanked by two SSR markers Barc232 and Wmc640, with the genetic distances of 3.7cM and 8.6cM, respectively.This study revealed genetic mechanism of three Chinese cultivars and the Triticum–Leymus mollis translocation resistance to stripe rust ,The result show the three Chinese cultivars and the Triticum–Leymus mollis translocation line have effective resistance to the dominant races in China. So this is important for revealing new resistant genes and wheat breeding program. The obtain moleculer markers in Mega will provide theoretical basis to wheat breeding in the use of Mega.

Genetic Analysis of Four Wheat Cultivars (Lines) and Molecular Mapping of Stripe Rust Resistance Gene in Mega

Abstract

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