印度圆粒小麦抗条锈病新基因YrSph的遗传分析和SSR标记定位

Genetic analysis and mapping of a stripe rust resistance gene YrSph derived from Triticum sphaerococcum Perc.

抗条锈病小麦新种质D31是以印度圆粒小麦(Triticum sphaerococcum Perc.)AS384与普通小麦品系94-3854杂交、回交选育而成的新品系。用中国小麦条锈病菌(Puccinia striiformis f.sp. stritici)流行生理小种条中32号对D31和Tai-chung29的杂交后代进行苗期及成株期抗条锈性遗传分析。结果表明,D31对生理小种条中32号表现为全生育期近免疫抗性反应,其抗性由1对隐性基因控制,暂命名为YrSph。利用BSA法对构建的F2遗传作图群体进行SSR标记分析。通过对400对微卫星引物的筛选和群体分析表明,抗性基因与Xwmc149、Xwmc246、Xgwm372和Xwmc198具有连锁关系,其中与Xwmc246标记连锁较近,遗传距离为8.8 cM。基因和标记之间的顺序为Xwmc149-YrSph-Xwmc246-Xgwm372-Xwmc198。根据作图结果,将D31所含的抗条锈病基因YrSph定位于2A短臂上。基于该基因的作图位置与系谱分析,认为该基因可能是1个新的抗条锈病基因。

Stripe rust,caused by Puccinia striiformis f.sp.tritici（PST）,is one of the most devastating diseases in common wheat（Triticum aestivum L.）.A new common wheat line D31,developed from a cross of AS384（T.sphaerococcum Perc.） and 94-3854,is resistant to the currently prevailing physiological races of PST in China.With the objective of identifying and tagging the new gene for resistance to stripe rust in wheat line D31,F1 and F2 populations from the cross ＂Taichung 29＂/D31 were inoculated with Chinese PST race CYR32 in field trials.Genetic analysis indicated that the resistance to CYR32 in the line D31 was conferred by one recessive gene,temporarily designated as YrSph.The F2 populations inoculated with CYR32 were used for SSR analysis.It was found that four SSR markers Xwmc149,Xwmc246,Xgwm372 and Xwmc198 located on the short arm of chromosome 2A were linked to YrSph.Xwmc246 was the closest locus and showed a linkage distance of 8.8 cM to the resistance gene YrSph.The linkage map of YrSph and markers was constructed in order of Xwmc149-YrSph-Xwmc246-Xgwm372-Xwmc198.Pedigree analysis and associations with markers suggested that YrSph was likely to be a new stripe rust resistance gene.