Classical genetic and quantitative trait loci analyses of heterosis in a maize hybrid between two elite inbred lines
Classical genetic and quantitative trait loci analyses of heterosis in a maize hybrid between two elite inbred lines
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DOI：
10.1534/genetics.106.064493
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发表时间：
2007-05-01
期刊：
影响因子：
3.3
通讯作者：
Pe, Mario Enrico
中科院分区：
文献类型：
--
作者：
Frascaroli, Elisabetta;Cane, Maria Angela;Pe, Mario Enrico
杂种优势的利用是植物育种最突出的进展之一，但其遗传基础还不十分清楚。本研究以玉米B73 × H99单交组合为材料，采用经典的遗传和数量性状基因座（QTL）分析方法，对玉米杂种优势进行了研究。材料为基础世代、衍生的142个重组自交系（RILs）和142个重组自交系与各自亲本及其F1杂交获得的3个测交群体。苗重（SW）、单株粒数（NK）和籽粒产量（戈伊）的杂种优势均大于100%，平均显性度大于1。SW和NK的上位性显著，而戈伊的上位性不显著。结果表明，在多数情况下，这些QTL位于低优势性状的加性-显性范围内，而在株高（PH）、SW、NK和戈伊等性状的QTL则位于显性-超显性范围内。只有少数QTL具有双基因上位性。杂合性水平与表型性状的相关性极显著，尤其是对戈伊的相关性，进一步证实了显性效应的重要性。部分染色体区域出现SW、PH、NK和戈伊的超显性QTL重叠，表明对植株整体活力具有多效性效应。
The exploitation of heterosis is one of the most outstanding advancements in plant breeding, although its genetic basis is not well understood yet. This research was conducted on the materials arising from the maize single cross B73 X H99 to study heterosis by procedures of classical genetic and quantitative trait loci (QTL) analyses. Materials were the basic generations, the derived 142 recombinant inbred lines (RILs), and the three testcross populations obtained by crossing the 142 RILs to each parent and their F-1. For seedling weight (SW), number of kernels per plant (NK), and grain yield (GY), heterosis was > 100% and the average degree of dominance was > 1. Epistasis was significant for SW and NK but not for GY. Several QTL were identified and in most cases they were in the additive-dominance range for traits with low heterosis and mostly in the dominance-overdominance range for plant height (PH), SW, NK, and GY. Only a few QTL with digenic epistasis were identified. The importance of dominance effects was confirmed by highly significant correlations between heterozygosity level and phenotypic performance, especially for GY. Some chromosome regions presented overlaps of overdominant QTL for SW, PH, NK, and GY, suggesting pleiotropic effects on overall plant vigor.