Soybean [Glycine max (L.) Merr.] reproductive structures are temperature-sensitive, with a reproductive optimum of 22 to 24 °C. Currently, parts of the US soybean growing region experience consistent late-season drought stress, resulting in the adoption of agronomic practices that favor early maturity groups. This approach is the Early Soybean Production System and has boosted yields and on-farm returns on investment. However, seeds produced under this system develop under higher temperatures than standard practices, and frequently have decreased seed quality, loss of value, and unacceptable germination rates. Climate change may result in more widespread late-season drought and elevated temperatures during seed filling. The ancestors of all modern US high-yielding soybean lines lack substantial resistance to heat-induced seed degradation, but an unadapted plant introduction (PI 587982A) can maintain ∼95% quality and germination under the same conditions. Inconsistent germination and emergence defects are associated with increased bioavailable phosphorus and reduced phytic acid. To evaluate these traits’ interaction, a backcross recombinant inbred line population was developed, and emergence and germination were evaluated in seed produced in six greenhouse and field environments. Two mutant alleles (lpa1a and lpa2a) were linked to decreased germination and emergence; this effect was pronounced under elevated temperatures. A novel major-effect heat tolerance quantitative trait locus derived from PI 587982A was identified and found to be associated with positive effects on overall germination and emergence. These results open the potential application of marker-assisted selection for tolerance to elevated temperatures and may accelerate the development of germplasm and cultivars with high-quality seed.

中文翻译：

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大豆耐热种子降解和低植酸抗性的定量性状基因座定位

大豆 [甘氨酸最大值(L.) Merr.] 繁殖结构对温度敏感，繁殖最佳温度为 22 至 24 °C。目前，美国大豆种植区的部分地区经历了持续的晚季干旱压力，导致采用有利于早熟群体的农艺实践。这种方法是早期大豆生产系统，提高了产量和农场投资回报。然而，在该系统下生产的种子在比标准做法更高的温度下发育，并且经常降低种子质量、价值损失和不可接受的发芽率。气候变化可能导致更广泛的晚季干旱和种子灌浆期间温度升高。所有现代美国高产大豆品系的祖先都对热诱导的种子降解缺乏实质性的抵抗力，但是在相同条件下，未适应的植物引入（PI 587982A）可以保持约 95% 的质量和发芽率。不一致的发芽和出苗缺陷与增加的生物可利用磷和减少的植酸有关。为了评估这些性状的相互作用，开发了回交重组自交系群体，并在六个温室和田间环境中生产的种子中评估了出苗和发芽。两个突变等位基因（在六个温室和田间环境中生产的种子中评估了出苗和发芽。两个突变等位基因（在六个温室和田间环境中生产的种子中评估了出苗和发芽。两个突变等位基因（lpa1a和lpa2a ) 与发芽和出苗减少有关；这种效果在升高的温度下很明显。鉴定了一种源自 PI 587982A 的新型主要效应耐热性数量性状基因座，并发现它与对整体萌发和出现的积极影响有关。这些结果开启了标记辅助选择对高温耐受性的潜在应用，并可能加速具有优质种子的种质和栽培品种的开发。