Fine Mapping Of The Gene Encoding A Drought Responsive Protein In Common Wheat

Global drought problems increasingly serious, drought is the main stress factor of wheatproduction. Selective breeding or popularity of new wheat cultivars was one of economicaland effective solutions to the problem. It is important for breeding wheat cultivars withresistant drought to analyze relationship between and wheat drought resistance and excavatemolecular markers of the genes which closely related to drought resistance.In this study, the seedlings of128wheat cultivars (lines) were treated with SDS-PAGEmethod was used to detect an about66.2kDa responsive protein in cultivars (lines) and F3populations of hybridized combination (Jinmai47×Xinong2208) seedling stages which weretreated with-0.5MPa PEG-6000stress for48h. The relationship between the expression ofresponsive protein and drought resistance was analyzed. Depending on the geneticcharacteristics of the protein expression in F3populations, combined with SSR molecularmarkers to determine the gene loci and linkage markers. The main study results showedbelow:1、Identification of128wheat cultivars (lines) of drought resistance for one year in twofield, average drought resistance index was0.90, there are5cultivars (lines) with highresistant, including13cultivars (lines) with resistant,59cultivars (lines) with mediumresistant,31cultivars (lines) with sensitivity,20cultivars (lines) with high sensitivity.2、The result indicated that among detected128cultivars (lines),67cultivars (lines)expressed the responsive protein which existed average DI (1.00) extremely significantdifference compared with61cultivars (lines)(0.80) without the protein expressed (P<0.01).Therefore, molecule weight about66.2KDa responsive protein had a close and positiverelationship with the drought resistance.3、In accordance with the genetic characteristics of the protein expression in F3populations, combined with SSR molecular markers to determine the gene loci and linkagemarkers. The response protein was controlled by one dominant gene designated as RpJM47,and five SSR markers including Xbarc56、Xbarc117、Xbarc197、Xgwm129andXgwm304located on chromosome arm5AS were linked to this gene, the closest flanking makers wereXbarc56and Xbarc117with genetic distances of2.2cM and2.9cM respectively. Twoflanking SSR markers, Xbarc56and Xbarc117, were used to test128wheat cultivars (lines). As a result, there are67cultivars (lines) had the same polymorphic bands as Jinmai47, whichaverage DI (1.02) extremely significant difference compared with other cultivars (lines)(0.78)(P<0.01).There are drought resistant wheat germplasm resources was selected through128cultivars (lines) drought resistance identification, and molecule weight about66.2KDaresponsive protein had a close positive relationship with the drought resistance could beconfirmed in this study. The polymorphic SSR markers play an important role in wheatmolecular marker selection and breeding.