Desoky El-Sayed M, Mansour Elsayed, Ali Mohamed M A, Yasin Mohamed A T, Abdul-Hamid Mohamed I E, Rady Mostafa M, Ali Esmat F
Botany Department, Faculty of Agriculture, Zagazig University, Zagazig 44519, Egypt.
Department of Crop Science, Faculty of Agriculture, Zagazig University, Zagazig 44519, Egypt.
Plants (Basel). 2021 Feb 12;10(2):354. doi: 10.3390/plants10020354.
The influence of 24-epibrassinolide (EBR), applied to leaves at a concentration of 5 μM, on plant physio-biochemistry and its reflection on crop water productivity (CWP) and other agronomic traits of six maize hybrids was field-evaluated under semi-arid conditions. Two levels of irrigation water deficiency (IWD) (moderate and severe droughts; 6000 and 3000 m water ha, respectively) were applied versus a control (well-watering; 9000 m water ha). IWD reduced the relative water content, membrane stability index, photosynthetic efficiency, stomatal conductance, and rates of transpiration and net photosynthesis. Conversely, antioxidant enzyme activities and osmolyte contents were significantly increased as a result of the increased malondialdehyde content and electrolyte leakage compared to the control. These negative influences of IWD led to a reduction in CWP and grain yield-related traits. However, EBR detoxified the IWD stress effects and enhanced all the above-mentioned parameters. The evaluated hybrids varied in drought tolerance; Giza-168 was the best under moderate drought, while Fine-276 was the best under severe drought. Under IWD, certain physiological traits exhibited a highly positive association with yield and yield-contributing traits or CWP. Thus, exogenously using EBR for these hybrids could be an effective approach to improve plant and water productivity under reduced available water in semi-arid environments.
在半干旱条件下，对六个玉米杂交种进行田间评估，研究以5 μM浓度叶面喷施24-表油菜素内酯（EBR）对植物生理生化的影响及其对作物水分生产率（CWP）和其他农艺性状的反映。设置了两个灌溉水分亏缺（IWD）水平（中度和重度干旱，分别为6000和3000立方米/公顷），并与对照（充分灌溉，9000立方米/公顷）进行比较。IWD降低了相对含水量、膜稳定性指数、光合效率、气孔导度、蒸腾速率和净光合速率。相反，与对照相比，由于丙二醛含量和电解质渗漏增加，抗氧化酶活性和渗透调节物质含量显著增加。IWD的这些负面影响导致CWP和与籽粒产量相关的性状降低。然而，EBR减轻了IWD胁迫的影响并提高了上述所有参数。所评估的杂交种在耐旱性方面存在差异；Giza-168在中度干旱下表现最佳，而Fine-276在重度干旱下表现最佳。在IWD条件下，某些生理性状与产量、产量构成性状或CWP表现出高度正相关。因此，在半干旱环境中，对这些杂交种外源施用EBR可能是提高植物和水分生产率的有效途径。
