Waterlogging is a critical abiotic stress increasing in importance due to more intense, erratic rainfall associated with climate change. Waterlogging leads to significant yield losses in sensitive crops, such as soybean (Glycine max [L.] Merr.). Identifying soybean genotypes and traits associated with better waterlogging tolerance is of high interest. We assessed the response of six soybean genotypes, selected from a field screening of over 190 genotypes, to 10 days of waterlogging at the R1 (onset of flowering) and R4 (grain filling) stages. We evaluated yield and its components, as well as shoot and root dry weights (DW) at the end of the waterlogging treatments and at maturity, along with morphological traits such as plant branch number, stem diameter and plant height. By integrating all these traits, a waterlogging tolerance index (WTI) was calculated for each genotype to rank their sensitivity. The WTI showed variations among genotypes from 0.61 to 0.77, indicating genotypic variation in response to waterlogging. Greater reductions in root DW compared to shoot DW were observed immediately after waterlogging. By maturity, shoot DW of waterlogged plants was more severely reduced than root DW in all genotypes. Despite similar DW losses at R1 and R4 at physiological maturity, seed number per plant and 100‐seed weight responses differed between the treatments. Genotypes that performed well under control conditions suffered significant yield reductions of 70%–85% after waterlogging, mainly due to fewer fertile nodes and seeds per pod, with some also experiencing a notable decrease in 100‐seed weight. In contrast, other genotypes had milder responses, with less severe reductions in seed and pod traits. Identifying breeding soybean genotypes tolerant to waterlogging during reproductive stages that maintain the number of fertile nodes and pods per node without changes in seeds per pod could significantly mitigate yield losses from waterlogging.

中文翻译：

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确定影响生殖阶段涝灾下大豆（Glycine max）产量的数值成分


由于与气候变化相关的更加强烈、不稳定的降雨，涝灾是一种严重的非生物胁迫，其重要性日益增加。涝渍会导致敏感作物（如大豆 (Glycine max [L.] Merr.)）的产量大幅下降。鉴定与更好的耐涝性相关的大豆基因型和性状引起了人们的高度关注。我们评估了从 190 多个基因型的田间筛选中选出的 6 种大豆基因型在 R1（开花期）和 R4（灌浆期）阶段对 10 天涝灾的反应。我们评估了产量及其组成部分，以及淹水处理结束时和成熟时的芽和根干重（DW），以及植物分枝数量、茎直径和株高等形态性状。通过整合所有这些性状，计算每个基因型的耐涝指数（WTI），以对其敏感性进行排名。 WTI 显示基因型之间的变化范围为 0.61 至 0.77，表明基因型对涝害的反应发生变化。与芽干重相比，在淹水后立即观察到根干重显着降低。到成熟时，在所有基因型中，浸水植物的茎干重比根干重降低更严重。尽管生理成熟度时 R1 和 R4 的干重损失相似，但处理之间每株种子数和 100 粒种子重量的反应不同。在对照条件下表现良好的基因型在淹水后产量显着下降70%–85%，这主要是由于可育节和每个荚的种子减少，有些基因型的百粒重也显着下降。相比之下，其他基因型的反应较温和，种子和豆荚性状的下降不太严重。 鉴定在繁殖阶段耐涝的育种大豆基因型，保持可育节和每个节点的豆荚数量而不改变每个豆荚的种子，可以显着减轻涝害造成的产量损失。