玉米大斑病抗性基因的QTL定位

以Mo17和黄早四为亲本,构建了包含239份F9代重组自交系的分离群体,并用103个微卫星标记构建了遗传连锁图谱,该图谱覆盖了玉米基因组1455.4 cM,标记间的平均间距为14.1 cM。通过人工接种分析了亲本及R IL群体对大斑病菌的抗性表现,并用复合区间作图法对抗性QTL进行了作图分析,结果在玉米第2染色体定位了3个与标记Bn lg1520、Um c1635和Bn lg125连锁的QTL,可分别解释表型方差的13.89%、19.33%和14.36%;另外还在第8染色体上定位了相邻的与标记Um c1327和Bn-lg2235紧密连锁的2个QTL,可分别解释表型方差的9.33%和7.62%。

QTL mapping for resistance to northern corn leaf blight in maize

Northern corn leaf blight(NCLB) is one of the most widespread disease in maize commercial production zone in the world,which caused serious yield losses in susceptible cultivars.Exserohilum turcicum,including many differential races is the major pathogeny.The mechanism for resistance to NCLB is very complicated in maize,because of different resistant mechanism according to different races in Maize.In order to realize clearly the resistance mechanism,we constructed F9 RIL(Recombinant inbred line) population including 239 RILs derived from a cross of Mo17 and Huangzao4,and the microsatellite marker linkage map of maize was constructed including 103 loci,covering 1455.4 cM in maize genome with an interval length of 14.1 cM.The parents and their RILs were evaluated on resistance to NCLB in field trials via artificial inoculation.The method of composite interval mapping was employed for QTL (Quantitative trait locus) detection,as results,Three QTLs linked with markers Bnlg1520,Umc1635 and Bnlg125,were identified on chromosome 2,which could explain 13.89 %,19.33 % and 14.36 % of the phenotypic variance,respectively.Another 2 QTLs,linked with Umc1327 and Bnlg2235,were located on chromosome 8,which could explain 9.33 % and 7.62 % of the phenotypic variance,respectively.The research results will contribute to understand deeply the mechanism for resistance to NCLB in maize,and to instruct NCLB-resistance breeding research.