College of Agronomy, Henan Agricultural University, Zhengzhou, China.
J Appl Genet. 2011 Nov;52(4):403-6. doi: 10.1007/s13353-011-0054-0. Epub 2011 May 11.
Understanding the inheritance of resistance to Fusarium ear rot is a basic prerequisite for an efficient resistance breeding in maize. In this study, 250 recombinant inbred lines (RILs) along with their resistant (BT-1) and susceptible (N6) parents were planted in Zhengzhou with three replications in 2007 and 2008. Each line was artificially inoculated using the nail-punch method. Significant genotypic variation in response to Fusarium ear rot was detected in both years. Based on a genetic map containing 207 polymorphic simple sequence repeat (SSR) markers with average genetic distances of 8.83 cM, the ear rot resistance quantitative trait loci (QTL) were analyzed by composite interval mapping with a mixed model (MCIM) across the environments. In total, four QTL were detected on chromosomes 3, 4, 5, and 6. The resistance allele at each of these four QTL was contributed by resistant parent BT-1, and accounted for 2.5-10.2% of the phenotypic variation. However, no significant epistasis interaction effect was detected after a two-dimensional genome scan. Among the four QTL, one QTL with the largest effect on chromosome 4 (bin 4.06) can be suggested to be a new locus for resistance to Fusarium ear rot, which broadens the genetic base for resistance to the disease and can be used for further genetic improvement in maize-breeding programs.
了解对镰刀菌穗腐病的抗性遗传是玉米高效抗性育种的基本前提。本研究于 2007 年和 2008 年在郑州以三个重复种植了 250 个重组自交系（RIL）及其抗性（BT-1）和敏感（N6）亲本。每条线均采用钉孔法进行人工接种。在这两年中，均检测到对镰刀菌穗腐病的显著基因型变异。基于包含 207 个多态性简单重复序列（SSR）标记的遗传图谱，平均遗传距离为 8.83 cM，利用混合模型（MCIM）在环境间进行复合区间作图，对穗腐病抗性数量性状位点（QTL）进行了分析。共检测到四个位于 3、4、5 和 6 号染色体上的 QTL。这些四个 QTL 中的每个抗性等位基因均来自抗性亲本 BT-1，占表型变异的 2.5-10.2%。然而，经过二维基因组扫描后，未检测到显著的上位性互作效应。在这四个 QTL 中，4 号染色体上（bin 4.06）的一个 QTL 对穗腐病的抗性效应最大，可以认为是一个新的抗镰刀菌穗腐病的位点，拓宽了对该病害的抗性遗传基础，并可用于玉米育种计划的进一步遗传改良。
