National Maize Improvement Center of China, China Agricultural University, 2 West Yuanmingyuan Road, Haidian District, Beijing 100193, People's Republic of China.
Theor Appl Genet. 2012 Dec;125(8):1797-808. doi: 10.1007/s00122-012-1954-z. Epub 2012 Aug 18.
Gray leaf spot (GLS), caused by the causal fungal pathogen Cercospora zeae-maydis, is one of the most serious foliar diseases of maize worldwide. In the current study, a highly resistant inbred line Y32 and a susceptible line Q11 were used to produce segregating populations for both genetic analysis and QTL mapping. The broad-sense heritability (H (2)) for GLS resistance was estimated to be as high as 0.85, indicating that genetic factors played key roles in phenotypic variation. In initial QTL analysis, four QTL, located on chromosomes 1, 2, 5, and 8, were detected to confer GLS resistance. Each QTL could explain 2.53-23.90 % of the total phenotypic variation, predominantly due to additive genetic effects. Two major QTL, qRgls1 and qRgls2 on chromosomes 8 and 5, were consistently detected across different locations and replicates. Compared to the previous results, qRgls2 is located in a 'hotspot' for GLS resistance; while, qRgls1 does not overlap with any other known resistance QTL. Furthermore, the major QTL-qRgls1 was fine-mapped into an interval of 1.4 Mb, flanked by the markers GZ204 and IDP5. The QTL-qRgls1 could enhance the resistance percentages by 19.70-61.28 %, suggesting its usefulness to improve maize resistance to GLS.
灰斑病（GLS）是由病原菌玉米尾孢菌引起的一种严重的玉米叶部病害，在全球范围内对玉米造成了严重威胁。本研究以高抗自交系 Y32 和感病自交系 Q11 为材料，构建了分离群体，用于遗传分析和 QTL 定位。GLS 抗性的广义遗传力（H （2））高达 0.85，表明遗传因素在表型变异中起着关键作用。在初始 QTL 分析中，共检测到 4 个 QTL，分别位于第 1、2、5 和 8 号染色体上，可赋予玉米对 GLS 的抗性。每个 QTL 可解释 2.53-23.90%的总表型变异，主要由加性遗传效应引起。在不同地点和重复试验中均检测到位于第 8 号和第 5 号染色体上的两个主效 QTL-qRgls1 和 qRgls2。与之前的结果相比，qRgls2 位于 GLS 抗性的“热点”区域，而 qRgls1 与其他已知的抗性 QTL 不重叠。此外，主效 QTL-qRgls1 被精细定位到一个 1.4 Mb 的区间内，由标记 GZ204 和 IDP5 侧翼。QTL-qRgls1 可将抗性百分比提高 19.70-61.28%，这表明其在提高玉米对 GLS 的抗性方面具有潜在的应用价值。
