QTL underlying crop adaptation to mega-environments in soybean

利用外来种质资源来提高作物的生产力受到限制，因为根据所使用的物种和种质资源的不同，已经遇到了相对较低和不同的成功。在大豆方面，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很少使用育种材料交换，即使是来自相似种植区的材料。通常，在非寄主环境中缺乏环境适应性阻碍了使用外来种质的进展，导致在后代中很少恢复或超过适应亲本的产量。如果种子产量是衡量一种特定作物适应潜力的最终标准，那么它似乎不能仅仅由成熟度组或引进材料来自的纬度来解释。在之前的NSERC发现基金中，我们已经确定了普遍与特定大陆的数量性状位点（QTL）的比例似乎推动了对大环境的适应力量。在本建议中，我们将尝试解决以下问题。繁殖种群所处的巨大环境是否会影响基因型的非随机选择，即使在假设随机选择的育种方法中也是如此？即使育种方法假设是随机的，分离扭曲是否由基因型的非随机选择引起？显示分离扭曲的标记在产量QTL的表达中起着多么重要的作用？互作QTL（上位性）在决定适应中的作用是什么？中国种质资源中所观察到的种子和农艺性状QTL等位基因的部分多样性是否可以部分解释为中国大豆育种计划中对野生大豆祖先甘氨酸大豆的更多使用？这项研究的概念意义在于，确定作物适应的潜在遗传原理可能有助于发展更具战略性和基于遗传的新遗传变异渗入许多物种。

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.