Abstract To keep plant height (PH) stable in various densities, mapping QTL underlying te response of PH to density is of importance for soybean breeding. In this study, two soybean RIL populations were planted under two densities in two environments and PH at the pod-bearing stage (PBS), seed-filling stage (SFS) and maturity stage (MS) were measured to identify QTL controlling PH and its response to density increment. Expression of QTL controlling PH varied due to the change of seeding density, and the response to density (RD) of PH at SFS and MS surpassed that at PBS in both populations. Total 25 PH QTL and 8 RD QTL were identified which functioned on PH at three developmental stages. Of 25 PH QTL, 14, 8 and 8 were detected at PBS, SFS and MS, respectively. Three QTL could be expressed at two stages, and thirteen, seven and six QTL played roles separately at PDS, SFS and MS, respectively. Four QTL were expressed in the two seeding densities, and twelve and ten QTL showed effects specifically at low and high seeding density, respectively. Among eight RD QTL, five, two and one acted on PH at PBS, SFS and MS, and five and three QTL functioned in two environments, respectively. The information found in the present research lays the foundation for molecular design breeding on improving PH with stability in multiple densities in soybean.

中文翻译：

---

定位三个发育阶段植株高度的 QTL 及其对大豆密度的响应 [Glycine max (L.) Merri.]

摘要 为了在各种密度下保持株高（PH）稳定，绘制PH对密度响应的QTL对于大豆育种具有重要意义。在本研究中，两个大豆 RIL 种群在两种环境中以两种密度种植，并测量了结荚期 (PBS)、种子灌浆期 (SFS) 和成熟期 (MS) 的 PH 值以识别控制 PH 值的 QTL 及其影响对密度增量的响应。控制PH的QTL表达因播种密度的变化而变化，SFS和MS对PH的密度（RD）响应在两个种群中均超过PBS。共鉴定出 25 个 PH QTL 和 8 个 RD QTL，它们在三个发育阶段对 PH 起作用。在 25 个 PH QTL 中，分别在 PBS、SFS 和 MS 处检测到 14、8 和 8 个。三个QTL可以在两个阶段表达，13个，7 个和 6 个 QTL 分别在 PDS、SFS 和 MS 中发挥作用。4 个 QTL 在两种播种密度下表达，12 个和 10 个 QTL 分别在低播种密度和高播种密度下表现出特异性。8个RD QTL中，5个、2个和1个在PBS、SFS和MS下作用于PH，5个和3个QTL分别在两种环境中起作用。本研究发现的信息为提高大豆多密度稳定PH的分子设计育种奠定了基础。分别。本研究发现的信息为提高大豆多密度稳定PH的分子设计育种奠定了基础。分别。本研究发现的信息为提高大豆多密度稳定PH的分子设计育种奠定了基础。