尾孢菌引起的玉米灰斑病严重影响着玉米生产，发掘抗灰斑病抗源材料及抗病基因并应用于抗病品种选育是经济有效的防控途径。玉米自交系齐319高抗灰斑病等多种玉米病害，因此，发掘该自交系的抗灰斑病基因，对培育玉米抗病品种具有重要意义。本研究利用齐319与10个不同抗病水平的玉米自交系组配的F1及其与感病自交系丹340、龙抗11构建的F2群体为试材，通过人工接种鉴定，研究自交系齐319对灰斑病的抗性遗传规律。研究结果表明：选用齐319作抗性亲本，由其组配杂交组合可以明显降低灰斑病发病程度，除与高感材料组配外，均能使杂交组合抗病性达到中抗以上水平；利用单个分离世代分析，齐319与龙抗11组配的后代群体符合B-2模型，即两对加性-显性主基因遗传模型；与丹340组配后代群体符合B-1模型，即两对加性-显性-上位性主基因遗传模型。利用齐319组配群体，在不同的遗传背景下，齐319均会表现出2对主效抗性基因，在龙抗11背景下表现出的主基因遗传率更高，基因作用方式更简单。该研究结果为齐319中抗灰斑病基因的发掘和利用奠定了基础。
英文摘要:
Gray leaf spot (GLS), caused by the Cercospora, poses a grave threat to maize production. To explore resistance to gray leaf spot for resistance materials and disease resistance genes, and applied to the breeding of resistant varieties would provide a cost-effective mean of controlling GLS. Maize inbred lines Qi319 is high resistance to gray leaf spot and other diseases. Therefore, it is vital to explore the resistance gene in Qi319 for cultivating the resistant varieties of maize. In this study, Qi319 and the level of resistance to the GLS of 10 maize inbred lines were used to produce F1, and a highly resistance inbred lines Qi319 and susceptible inbred lines Dan340, Longkang11 were used to produce segregating population for inheritance of resistance to gray leaf spot by using artificial inoculation identification method. The results showed that the incidence of gray leaf spot of the hybrid would be significant reduced when the Qi319 as a resistant parent in addition to cross with high susceptible inbred lines, the level of resistance to the GLS was increased to the middle level. The segregation analysis of single separate generation was adopted to study the genetic laws of GLS, the result showed that parents Qi319 and Longkang11 were in accordance with the B-2 model, namely two pairs of major genes with additive-dominant effects. The parents Qi319 and Longkang11 were in accordance with the B-1 model, namely two pairs of major genes with additive-dominant-epistatic effects. Qi319 was used to produce population, it could show two pairs of major resistance genes in different genetic background, but Qi319 could show a higher genetic rate of the main gene in the background of the parent LongKang11. The results of the study laid the foundation for the discovery and utilization of the resistance gene to gray leaf spot in Qi319.
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