Drought stress is one of the most important factors limiting soybean [Glycine max (L.) Merr.] productivity and reducing yield stability. Soybean breeders need phenotypic and genotypic tools to improve drought stress tolerance, but most of available strategies are expensive and unaffordable for small-scale public breeding programs. In this study, elite germplasm of a locally adapted breeding population was used to estimate a yield stability index as an indicator of drought response. In order to associate yield stability of analyzed genotypes to drought response, water deficit scenarios related to the crop cycle group were defined. Four groups of genotypes were identified in relation to yield stability: two groups showed stables yield (without interaction with water deficit scenarios), and two groups showed unstable yield (with crossover interaction with water deficit scenarios). This phenotypic information was used to identify genomic regions and candidate genes associated with yield stability index. A new method for the definition of a quantitative trait loci (QTL) region was developed based on the probability of marker pairwise of belonging to four linkage disequilibrium (LD) categories. Seven QTL were found and their implication on drought tolerance was further supported by linkage to previously reported QTL for water use efficiency trait.

中文翻译：

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GWAS 在大豆小育种群体中产量稳定性的综合分析

干旱胁迫是限制大豆的最重要因素之一 [ Glycine max(L.) Merr.] 生产力和降低产量稳定性。大豆育种者需要表型和基因型工具来提高干旱胁迫耐受性，但大多数可用的策略对于小型公共育种计划来说价格昂贵且无法承受。在这项研究中，当地适应育种种群的优良种质被用于估计作为干旱响应指标的产量稳定性指数。为了将分析的基因型的产量稳定性与干旱响应联系起来，定义了与作物周期组相关的缺水情景。确定了与产量稳定性相关的四组基因型：两组表现出稳定的产量（与缺水情景没有相互作用），两组表现出不稳定的产量（与缺水情景交叉相互作用）。该表型信息用于识别与产量稳定性指数相关的基因组区域和候选基因。基于标记成对属于四个连锁不平衡 (LD) 类别的概率，开发了一种用于定义数量性状位点 (QTL) 区域的新方法。发现了 7 个 QTL，它们对耐旱性的影响通过与先前报道的水分利用效率性状 QTL 的联系得到进一步支持。