利用近等基因系定位玉米粗缩病抗性QTL及分子标记辅助选择的研究

以1对近等基因系(NILs)构建的分离群体(NT4092/NT411)F1为材料,采用自然发病鉴定方法,以行发病率为表型值,在3种环境下对各株系进行粗缩病抗病性鉴定。应用完备区间作图法(ICIM)对玉米粗缩病抗性QTL进行分析,分离群体(NT4092/NT411)F1在两地三点检测到3个QTL,均位于第8染色体上,LOD值分别为24.03、10.29和17.02,分别解释了41.37%、20.51%和36.04%的表型变异,是能够稳定表达的主效QTL。泰安5月份和济宁5月份环境下检测到的主效QTL均位于phi121和UMC1817标记区间之内,遗传距离为15.47 cM,标记区间物理距离为92Mb;泰安6月份环境下检测到的主效QTL位于M6和M24标记区间之内,遗传距离为0.86 cM,标记区间物理距离为17.9 Kb。通过对4个分离群体辅助选择的可行性分析表明,这些主效QTL与玉米粗缩病抗性间呈极显著相关,其标记在CL313、1145、沈137等系谱来源相同或相近的自交系中可应用于抗玉米粗缩病育种的辅助选择。

Mapping of QTL for Resistance to Maize Rough Dwarf Disease Using Near-Isogenic Lines and Their Application in Molecular Marker-Assisted Selection

The mapping quantitative trait locus(QTLs) of resistance to Maize Rough Dwarf Disease(MRDD) were studied using one segregation populations from the crosses between NT409 and NT411. Reactions of the segregation populations to MRDD were investigated by natural infection method in three different environments, and scored by the incidence of MRDD. Based on inclusive composite interval mapping(ICIM) method, we identified three QTLs for resistance to MRDD using(NT409²/NT411) F₁ on chromosome 8. The contributions of the three QTLs to the total variation were 41.37%, 20.51% and 36.04% with LOD scores being 24.03, 10.29 and 17.02, respectively. Two QTLs were mapped to a 16.47 cM region between the SSR markers phi121 and UMC1817, and with physical distance of 92 Mb in Tai'an May and Jining May. Another one was mapped to a 0.86 cM region between the SSR markers M6 and M24, and with physical distance of 17.9 Kb in Tai'an June. Through marker-assisted selection of feasibility analysis to four segregation populations indicated that these major QTLs were significantly correlated with resistance to MRDD, which could be used for marker-assisted selection for resistance to MRDD in breeding program.