水稻株高上位性效应和QE互作效应的QTL遗传研究(英文)

QTL Analysis for Epistatic Effects and QTL×Environment Interaction Effects on Final Height of Rice (Oryza sativa L.)

利用基于混合模型的QTL定位方法研究了由籼稻品种IR64和粳稻品种Azucena杂交衍生的DH群体在4个环境中的QTL上位性效应和环境互作效应。结果表明，上位性是数量性状的重要遗传基础，并揭示了上位性的几个重要特点。所有的QTL都参与了上位性效应的形成，64%的QTL还具有本身的加性效应。因此传统方法对QTL加性效应的估算会由于上位性的影响而有偏。其他36%的QTL没有本身的加性效应，却参与了48%的上位性互作，这些位点可能通过诱发和修饰其他位点而起作用。上位性的特点还包括，经常发现一个QTL与多个QTL发生互作；大效应的QTL也参与上位性互作；上位性互作受环境影响。QTL与环境的互作效应比QTL的主效应更多地被检测到，表明数量性状基因的表达易受环境影响。

QTLs with epistatic effects and environmental interaction effects for final height of rice were studied by mixed-model based QTL mapping with a doubled haploid population from IR64／Azucena in four environments. The results demonstrated the importance of epistasis as a genetic basis of the quantitative traits and also revealed several important features of this phenomenon. In the results, 100 per cent of QTLs were involved in epistasis, of which 64 per cent were found with significant additive effects. This might mean that the usual estimates of the QTL additive effects could be confounded by epistatic interactions and result in biased estimation unless epistatic effect is separated. The other 36 per cent did not have any significant additive effects of their own but were involved in 48 per cent of the identified epistatic interactions. Such loci might play the role of modifying agents that tend to activate other loci or modify the action of other loci. The other features of epistasis include as follows: it was fairly common for the same locus to get involved in interactions with more than one locus; the QTLs with relatively high magnitude of effects might also be involved in epistasis; and epistasis was sensitive to environmental interactions for their expression. QTL×environment (QE) interaction effects were detected more often than QTL main effects for plant height behavior, as might indicate that gene expression could be greatly affected by environments.