Genetic Analysis And Chromosomal Location Of A Recessive Resistance Gene For Powdery Mildew In Wheat (Triticum Aestivum L.)

Powdery mildew, caused by Erysiphe graminis f.sp. tritici is a worldwide disease, which spread through the air with many characteristics, such as wide adaptation, fast communication speed and variation. That disease is a threat to Chinese wheat production, especially worse in Sichuan Province, lead to tremendous economic loss. Training high resistant cultivars is the most economical, effective and environmental preventions. Although many powdery mildew genes have been identified, only a few effective powdery mildew resistance genes can be used. Therefore, to explore more new resistance genes has important theoretical and practical significance in wheat breeding.The strains Z09-970 is a optimization strains come from strains 970.The strains Z09-970 exhibits high resistant to the epidemic predominant race of powdery mildew in Sichuan Province, with good agronomic traits. Genetic analysis of its resistance to powdery mildew and linkage ananysis of the trains Z09-970 by a use of wheat SSR markers for chromosomal positioning were be researched in this paper.By conventional genetic analysis, with the susceptible wheat cultivar MY11 and Z09-970 reciprocal cross F1, hybrid F2 segregating populations as materials, inoculated by the natural powdery mildew of field, showed high resistant strains Z09-970 carrying a single recessive gene for powdery mildew, tentatively named PmZ970.Using segregation population group method (BSA), conduct genetic linkage analysis with 387 pairs wheat SSR primers and resistant parent Z09-970, susceptible parent MY11 and random 221 Z09-970×MY11 F2 separate plants, found PmZ970 located on wheat chromosome arm 5DL, four markers linked to gene PmZ970.Their order is: Xgwm271-Xgdm116-Xbarc110-Xbarc144-PmZ970, the relative genetic distance were 48.6cM,22.0 cM,27.0 cM and 9.4cM, among them Xbarc144 is most nearly to PmZ970,with relative distance of 9.4 cM.Comparing other three resistant Pm genes (Pm2, Pm34 and Pm35)located on 5D, found that PmZ970 was different from others, it maybe a new recessive gene on 5DL.This paper also discussed the use of wheat recessive resistance gens in wheat genetics and breeding and other aspects. Key words:wheat. Powdery mildew, recessive resistance gens, SSR, chromosomal positioning...