QTL underlying crop adaptation to mega-environments in soybean

使用外来种质来提高作物植物的生产力一直受到限制，这是由于所遇到的成功率相对较低且可变，这取决于所使用的物种和种质。在大豆中，在上个世纪首次引入祖先系之后，中国（起源和多样性中心）和北美大豆育种计划之间交换的育种材料很少使用，即使是来自相似种植区的材料。通常，在非宿主环境中缺乏环境适应性阻碍了使用外来种质的进展，导致后代很少恢复或超过适应亲本的产量。如果种子产量是某种作物适应潜力的最终衡量标准，那么似乎不能仅仅用成熟度组或引进材料的纬度来解释。在之前的NSERC发现资助中，我们已经确定了通用与大陆特异性数量性状基因座（QTL）的比例似乎驱动了对大环境的适应力。在本提案中，我们将试图解决以下问题。即使采用假设选择随机性的育种方法，育种群体发育的大环境是否会影响基因型的非随机选择？即使育种方法假设随机性，基因型的非随机选择是否会导致分离失真？显示偏分离的标记在产量QTL的表达中起着多么重要的作用？互作QTL（上位性）在决定适应性中的作用是什么？在中国种质资源中观察到的种子和农艺性状QTL等位基因的多样性是否可以部分地解释为中国大豆育种计划更多地使用野生大豆祖先Glycine soja？这项研究的概念意义在于，确定作物适应性的基本遗传原则可能有助于开发更具战略性和基于遗传的新遗传变异渗入到一些物种中。

The use of exotic germplasm to improve the productivity of crop plants has been limited due to relatively low and variable success that has been encountered, depending on the species and germplasm used. In soybean, after the initial introduction of ancestral lines in the last century, there has been little use of breeding materials exchanged between the Chinese (centre of origin and diversity) and North American soybean breeding programs, even for materials coming from similar growing regions. Typically, the lack of environmental adaptation in non-host environments has hampered progress in using exotic germplasm resulting in a rare recovery of, or surpassing, of the adapted parent's yield in the progeny. If seed yield is the ultimate measure of a given crop's adaptation potential, it does not seem to be explained solely by the maturity group or the latitude the introduced materials came from. Within the previous NSERC Discovery grant, we have determined that a ratio of universal vs. continent-specific quantitative trait loci (QTL) appears to drive the forces of adaptation to mega-environments. In this proposal, we will attempt to address the following questions. Does the mega-environment in which the breeding population is developed influence a non-random selection of genotypes, even when breeding methods that assume randomness of selection are practiced? Is segregation distortion caused by non-random selection of genotypes, even when breeding methods assume randomness? How important a role do markers that show segregation distortion play in the expression of yield QTL? What is the role of interacting QTL (epistasis) in determining adaptation? Can a portion of the observed diversity in QTL alleles for seed and agronomic traits in the Chinese germplasm be explained in part by the greater use of the wild soybean progenitor, Glycine soja, by the Chinese soybean breeding programs? The conceptual significance of this research is that the determining of the underlying genetic principles of crop adaptation may aid in the development of a more strategic and genetically-based introgression of new genetic variation into a number of species.