玉米抗矮花叶病QTL的定位分析

以黄早四（抗）和Mo 17（感）为亲本建立了239个RIL系的群体，利用该群体构建了包含101个SSR标记的遗传图谱，覆盖玉米基因组1422．7cM，标记间的平均距离为15.6cM。通过人工接种鉴定，评价了亲本及239个RIL系对MDMV病毒B株系的抗性反应。采用复合区间作图法对玉米矮花叶病抗性QTL进行了定位及其遗传效应分析，在第5，6染色体上各定位了控制发病率的1个微效QTL和一个主效QTL，分别与标记bnlg602，bnlg161连锁，其遗传效应能分别解释表型方差的2．3％和33．8％。在第6染色体上定位了控制病情指数的2个主效QTL，分别与标记bnlg161，y1 ssr连锁．其遗传效应分别能解释表型方差的56．5％和76．8％。

QTL MAPPING FOR MDMV-B RESISTANCE IN MAIZE

The MDMV (maize dwarf mosaic virus )-resistant inbred line Huazao4 and the highly susceptible inbred line Mo 17 were used to develop a population consisting of 239 RILs ( recombinant inbred lines). An SSR (simple sequence repeat) marker linkage map was constructed with 101 loci distributed in 10 linkage groups, covering 1 422.7 cM with an average interval length of 15.6 cM. Two hundred and thirty-nine RILs and their parental lines were evaluated for their resistance to MDMV-B strain under artificial inoculation. With the method of composite interval mapping, two QTLs (quantitative trait loci) for disease incidence, linked with markers bnlg 602 and bnlg 161 , were identified on chromosomes 5 and 6, which can explain 2. 3% and 33.8% of the phenotypic variance, respectively. Two QTLs for disease index on chromosome 6, linked with markers bnlg 161 and ylssr, were identified with major effects conferring MDMV-resistance, which can explain 56.5% and 76.8% of the phenotypic variance, respectively.