Naseer Muhammad Asad, Hussain Sadam, Mukhtar Ahmed, Rui Qian, Ru Guo, Ahmad Haseeb, Zhang Zhi Qin, Shi Li Bo, Asad Muhammad Shoaib, Chen Xiaoli, Zhou Xun Bo, Ren Xiaolong
Guangxi Key Laboratory for Agro-Environment and Agro-Product Safety, Key Laboratory of Crop Cultivation and Physiology, College of Agriculture, Guangxi University, Nanning, China.
College of Agronomy, Northwest A&F University, Yangling, China.
Front Plant Sci. 2024 Jul 29;15:1396929. doi: 10.3389/fpls.2024.1396929. eCollection 2024.
The uneven spatial and temporal distribution of light resources and water scarcity during the grain-filling stage pose significant challenges for sustainable crop production, particularly in the arid areas of the Loess Plateau in Northwest China. This study aims to investigate the combined effects of drought and shading stress on winter wheat growth and its physio-biochemical and antioxidative responses. Wheat plants were subjected to different drought levels- full irrigation (I100), 75% of full irrigation (I75), 50% of full irrigation (I50), and 25% of full irrigation (I25), and shading treatments - 12, 9, 6, 3 and 0 days (SD12, SD9, SD6, SD3, and CK, respectively) during the grain-filling stage. The effects of drought and shading treatments reduced yield in descending order, with the most significant reductions observed in the SD12 and I25 treatments. These treatments decreased grain yield, spikes per plant, 1000-grain weight, and spikelets per spike by 160.67%, 248.13%, 28.22%, and 179.55%, respectively, compared to the CK. Furthermore, MDA content and antioxidant enzyme activities exhibited an ascending trend with reduced irrigation and longer shading durations. The highest values were recorded in the I75 and SD12 treatments, which increased MDA, SOD, POD, and CAT activities by 65.22, 66.79, 65.07 and 58.38%, respectively, compared to the CK. The Pn, E, Gs, and iCO exhibited a decreasing trend (318.14, 521.09, 908.77, and 90.85%) with increasing shading duration and decreasing irrigation amount. Drought and shading treatments damage leaf chlorophyll fluorescence, decreasing yield and related physiological and biochemical attributes.
灌浆期光资源时空分布不均以及水资源短缺对作物可持续生产构成重大挑战，在中国西北黄土高原干旱地区尤为如此。本研究旨在探究干旱和遮荫胁迫对冬小麦生长及其生理生化和抗氧化反应的综合影响。在灌浆期，将小麦植株置于不同干旱水平——充分灌溉（I100）、充分灌溉的75%（I75）、充分灌溉的50%（I50）和充分灌溉的25%（I25），以及遮荫处理——12、9、6、3和0天（分别为SD12、SD9、SD6、SD3和CK）。干旱和遮荫处理对产量的影响按降序排列，SD12和I25处理减产最为显著。与CK相比，这些处理分别使籽粒产量、单株穗数、千粒重和每穗小穗数降低了160.67%、248.13%、28.22%和179.55%。此外，丙二醛（MDA）含量和抗氧化酶活性随灌溉量减少和遮荫时间延长呈上升趋势。I75和SD12处理的值最高，与CK相比，MDA、超氧化物歧化酶（SOD）、过氧化物酶（POD）和过氧化氢酶（CAT）活性分别增加了65.22%、66.79%、65.07%和58.38%。随着遮荫时间延长和灌溉量减少，净光合速率（Pn）、蒸腾速率（E）、气孔导度（Gs）和胞间二氧化碳浓度（iCO）呈下降趋势（分别下降318.14%、521.09%、908.77%和90.85%）。干旱和遮荫处理损害叶片叶绿素荧光，降低产量及相关生理生化指标。
