Climate change is predicted to increase the probability of soil waterlogging due to severe rainfall, causing significant damage to soybean at the germination stage. Germination under waterlogging is also greatly influenced by temperature. To clarify the variation in germination responses of soybean genotypes to waterlogging at different temperatures, the seeds of 15 soybean genotypes were treated by soaking for 2 days at four temperatures: 21 °C, 23 °C, 25 °C, 27 °C and 29 °C. Differences in the germination rate (GR) and normal seedling rate (NSR) were observed among soybean genotypes after soaking treatments regardless of the temperature. Among the examined genotypes, Iyodaizu was classified as waterlogging tolerant at the germination stage, and Tachinagaha was classified as sensitive. Interestingly, through the analyses of recombinant inbred lines (RILs) developed from a cross between Tachinagaha and Iyodaizu, quantitative trait loci (QTLs) for root development under hypoxia at the seedling stage of soybean were detected on chromosome 12 (Chr.12).We investigated whether the candidate QTL region for root development is involved in seed waterlogging tolerance by using a near-isogenic line (NIL), NIL-9-4-5. Interestingly, under soaking treatment, the GR and NSR of NIL-9-4-5, carrying the candidate QTL region, was nearly the same as that of Iyodaizu and was significantly higher than that of Tachinagaha. These results may indicate that the candidate QTL region for root development under hypoxia at the seedling stage located on Chr.12 contributes to the seed waterlogging tolerance of soybean plants at the germination stage.

中文翻译：

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大豆近等基因系证实了不同温度下种子耐涝性的 QTL

预计气候变化会增加强降雨导致土壤内涝的可能性，对发芽阶段的大豆造成重大损害。涝渍下的发芽也受温度的影响很大。为了阐明不同温度下大豆基因型对涝渍发芽反应的变化，将 15 个大豆基因型的种子在 21 °C、23 °C、25 °C、27 °C 和 29 四个温度下浸泡 2 天。 ℃。无论温度如何，浸泡处理后大豆基因型的发芽率（GR）和正常出苗率（NSR）均存在差异。在检查的基因型中，Iyodaizu 在发芽阶段被归类为耐涝，而 Tachinagaha 被归类为敏感。有趣的是，通过分析由 Tachinagaha 和 Iyodaizu 杂交产生的重组自交系 (RIL)，在 12 号染色体 (Chr.12) 上检测到大豆苗期缺氧条件下根发育的数量性状位点 (QTL)。根发育的候选 QTL 区域通过使用近等基因系 (NIL) NIL-9-4-5 参与种子耐涝。有趣的是，在浸泡处理下，携带候选QTL区域的NIL-9-4-5的GR和NSR与Iyodaizu几乎相同，并显着高于Tachinagaha。这些结果可能表明，位于Chr.12的苗期缺氧根系发育候选QTL区域有助于大豆植物萌发期种子耐涝性。