小麦条锈菌鉴别寄主Lee中抗性基因Yr7的微卫星标记

【目的】对近等基因系Taichung29*6/Lee对条锈菌（PST）菌系CYR27的抗性谱进行遗传分析，并运用微卫星技术对近等基因系Taichung29*6/Lee中的抗条锈性基因进行标记。【方法】将Taichung29*6/Lee 与Taichung29杂交、自交和测交并对双亲及其杂交后代进行苗期抗性鉴定。采用SSR技术，利用抗性供体Lee中含有目的基因Yr7的小麦抗条锈病近等基因系Taichung29*6/Lee，选用Yr7所在的2B染色体上88 对和Yr22、Yr23所在4D、6D染色体上22对SSR引物，对供试的Taichung29*6/Lee、Taichung29和Lee基因组DNA进行PCR扩增和电泳分析。【结果】根据F2分离群体的抗感单株分离比例，确定Taichung29*6/Lee对CYR27菌系的抗性为1个显性基因，2B染色体上的Xgwms526引物扩增出多态性谱带为Xgwms526/212bp和Xgwms526/216bp，并证明其DNA片段位点与抗条锈基因Yr7存在遗传连锁关系；用标记Xgwms526扩增F2作图群体的单株DNA，在75株抗病单株中，有22株扩增出A型带（Xgwm526-212bp），51株扩增出H型带（Xgwm526-212bp和Xgwm526-216），2株扩增出B型带（Xgwm526-216）；在31株感病株中，有4株扩增出H型带，27株扩增出B型带。【结论】通过Map Manager QTX 17b软件计算，确定Xgwm526标记位点与Yr7基因位点的遗传距离为5.3cM，标准差为2.3，LOD值为18.4。该标记Xgwm526可作为Yr7基因的SSR标记利用。

The Molecular Tagging of theYellow Rust Resistance Gene Yr7 in Wheat Transferred from Differential Host Lee Using Microsatellite Markers

【Objective】Using inheritance analysis for the rust reaction of seedling plants in Taichung29*6/Lee to CYR27 and SSR for tagging the resistance gene in Taichung29*6/Yrlee,made from the donor parent Lee and recurrent parent Taichung29.【Method】Using an assessment of the rust reaction of seedling plants in the F1, F2 and BC1 population for a set of crosses made between Lee, Taichung29 and Taichung29*6/Lee.According to WMS and WMC SSR primer sets in number of 88 distributed among 2B, 22 among 4D and 6D chromosomes, the PCR amplification, denatured PAGE and silver staining are used for detecting polymorphic bands.【Result】The proportions of resistant and susceptible plants obtained following inoculation of F2 populations with race CYR27 indicates that single dominant gene determines the reactions of Taichung29*6/Lee lines. For 22 primer sets distributed among 4D and 6D chromosomes, polymorphic bands are not identified between Taichung29*6/Yrlee and Taichung29. The primer pair Xgwms526 on 2B in number of 88 primer sets have two SSR amplified polymorphic bands Xgwms526/212 and Xgwms526/216 detected. Further screening the F2 resistant and susceptible individuals , it showed that Xgwm526 co-segregated with the resistant. gene in wheat and confirmed that the gene in Taichung29*6/Yrlee line is Yr7. The individuals of segregated F2 population are amplified using diagnostic primer Xgwm526, there are 22 A bands, 51 H bands and 2 B bands in 75 resistant individuals, while 27 B bands , 4 H bands in 31 susceptible individuals.【Conclusion】The results of software Map Manager QTX 17b analysis shows that the genetic distance between Xgwm526 and Yr7 was as 5.3 cM , LOD=18.4. Furthermore the marker Xgwm526 can be used for the detection of resistance gene Yr7 and for the pyramiding with other yellow rust resistance genes in wheat shows that the genetic distance between Xgwm526 and Yr7 was as 5.3 cM , LOD=18.4. Furthermore the marker Xgwm526 can be used for the detection of resistance gene Yr7 and for the pyramiding with other yellow rust resistance genes in wheat.