Jiangsu Key Laboratory of Crop Genetics and Physiology, Yangzhou University, Yangzhou, China.
Co-Innovation Center for Modern Production Technology of Grain Crops, Yangzhou University, Yangzhou, China.
PLoS One. 2018 Apr 9;13(4):e0195535. doi: 10.1371/journal.pone.0195535. eCollection 2018.
The occurrence of water stress during wheat growth is more frequent due to climate change. Three experiments (cyclic drought, cyclic waterlogging, and cyclic drought plus waterlogging) were conducted to investigate the effects of mild and severe cyclic/single water stress at elongation and heading stages on winter wheat (Triticum aestivum L.) yield. The effect of either mild drought at elongation or mild waterlogging at heading on wheat yield was not significant; however, significance did occur under other single water stresses. As the stress becomes more severe, the yield loss significantly increases. Extreme drought/waterlogging treatment at elongation caused a greater yield penalty than stress at heading stage. Except the combination of mild drought and mild waterlogging treatment, cyclic water stress significantly decreased wheat yields. The decrease in wheat yield under cyclic severe drought and waterlogging was significantly higher than any other treatment, with percentage decreases of 71.52 and 73.51%, respectively. In general, a yield reduction from mild cyclic water stress did not indicate more severe damage than single treatments; in contrast, grain yield suffered more when water stress occurred again after severe drought and waterlogging. Drought during elongation significantly decreased kernel number, whereas drought at heading/waterlogging during elongation and heading decreased the spike weight, which might be the main reason for the yield penalty. Furthermore, water stress caused variation in the decrease of total biomass and/or harvest index. The present study indicates comprehensive understanding of the types, degree, and stages of water stress are essential for assessing the impact of multiple water stresses on wheat yield.
由于气候变化，小麦生长过程中出现水分胁迫的情况更为频繁。本研究通过三个试验（周期性干旱、周期性渍水和周期性干旱加渍水），研究了拔节期和抽穗期轻度和重度周期性/单一水分胁迫对冬小麦产量的影响。拔节期轻度干旱或抽穗期轻度渍水对小麦产量没有显著影响，但在其他单一水分胁迫下则有显著影响。随着胁迫程度的加剧，产量损失显著增加。拔节期极端干旱/渍水胁迫造成的产量损失大于抽穗期胁迫。除轻度干旱和轻度渍水组合处理外，周期性水分胁迫显著降低了小麦产量。周期性重度干旱和渍水胁迫下小麦产量的降幅显著高于其他任何处理，分别为 71.52%和 73.51%。一般来说，轻度周期性水分胁迫导致的减产并不比单一处理造成的减产更严重；相反，在严重干旱和渍水后再次发生水分胁迫时，籽粒产量受到的影响更大。拔节期干旱显著降低了穗粒数，而拔节期和抽穗期干旱或渍水则降低了穗重，这可能是造成减产的主要原因。此外，水分胁迫导致总生物量和/或收获指数的减少。本研究表明，全面了解水分胁迫的类型、程度和阶段对于评估多种水分胁迫对小麦产量的影响至关重要。
