Division of Plant Sciences, College of Agriculture Food and Natural Resources, and Interdisciplinary Plant Group. Christopher S. Bond Life Sciences Center University of Missouri, Columbia, Missouri, USA.
Departments of Biological Sciences, College of Science, University of North Texas, Denton, Texas, USA.
Physiol Plant. 2021 May;172(1):41-52. doi: 10.1111/ppl.13269. Epub 2020 Dec 3.
A combination of drought and heat stress, occurring at the vegetative or reproductive growth phase of many different crops can have a devastating impact on yield. In soybean (Glycine max), a considerable effort has been made to develop genotypes with enhanced yield production under conditions of drought or heat stress. However, how these genotypes perform in terms of growth, physiological responses, and most importantly seed production, under conditions of drought and heat combination is mostly unknown. Here, we studied the impact of water deficit and heat stress combination on the physiology, seed production, and yield per plant of two soybean genotypes, Magellan and Plant Introduction (PI) 548313, that differ in their reproductive responses to heat stress. Our findings reveal that although PI 548313 produced more seeds than Magellan under conditions of heat stress, under conditions of water deficit, and heat stress combination its seed production decreased. Because the number of flowers and pollen germination of PI 548313 remained high under heat or water deficit and heat combination, the reduced seed production exhibited by PI 548313 under the stress combination could be a result of processes that occur at the stigma, ovaries and/or other parts of the flower following pollen germination.
干旱和热胁迫的结合，发生在许多不同作物的营养生长或生殖生长阶段，会对产量产生毁灭性的影响。在大豆（Glycine max）中，人们已经做出了相当大的努力来开发在干旱或热胁迫条件下具有更高产量的基因型。然而，这些基因型在干旱和热胁迫组合条件下的生长、生理响应，以及最重要的种子生产方面的表现，在很大程度上是未知的。在这里，我们研究了水分亏缺和热胁迫组合对两种大豆基因型（Magellan 和 Plant Introduction [PI] 548313）的生理学、种子生产和单株产量的影响，这两种基因型在对热胁迫的生殖响应方面存在差异。我们的研究结果表明，尽管在热胁迫条件下，PI 548313 的种子产量高于 Magellan，但在水分亏缺和热胁迫组合条件下，其种子产量下降。因为 PI 548313 的花数和花粉萌发在热或水分亏缺以及热胁迫组合下仍然很高，PI 548313 在胁迫组合下表现出的减少的种子生产可能是花粉萌发后柱头、子房和/或花的其他部分发生的过程的结果。
