干旱胁迫对大麦叶片表皮蜡质含量及主要生理指标的影响

为了探究大麦对干旱胁迫的反应机制,采用裂区设计研究了干旱胁迫对不同大麦品种灌浆期旗叶和旗叶鞘表皮蜡质含量及主要生理指标的影响。结果表明,与正常水分处理相比,干旱胁迫可促进大麦表皮蜡质的合成;大麦不同品种间蜡质含量差异显著,抗旱品种的蜡质含量显著高于干旱敏感品种。在干旱胁迫下,大麦叶片相对含水量、叶绿素含量及气孔导度显著降低,且抗旱品种降低幅度较干旱敏感品种缓慢;蒸腾速率和胞间CO2浓度显著增加,且抗旱品种的增加幅度低于干旱敏感品种。品种因素对大麦叶片蜡质含量、净光合速率、气孔导度的影响较水分处理的影响大。大麦表皮蜡质含量与水分利用效率呈显著正相关,表明表皮蜡质对提高大麦抗旱性有一定积极意义。

Effects of Water Stress on Epicuticular Wax Content and Main Physiological Parameters of Barley

The epicuticular wax contents of flag leaf and its sheath, and main physiological parameters of 6 barley cultivars in grain filling stage were studied by adopting split plot design to understand the effects of water stress on epicuticular wax content and main physiological parameters of barley. The results showed that the epicuticular wax contents could be affected by water stress, the epicuticular wax contents under water stress were significantly higher than that under normal irrigation; the epicuticular wax contents differed significantly among tested cultivars, suggesting that the epicuticular wax contents were determined not only by genetic factors but also by environmental factors. The relative water contents, chlorophyll contents and stomata conductance decreased remarkably under water stress, the transpiration rates and intercellular CO₂ concentrations increased significantly, but the net photosynthetic rates did not differed significantly. The effects of cultivar on epicuticular wax content, photosynthetic rate, stomata conductance were bigger than that of water treatment. The significant correlation between epicuticular wax content and water use efficiency was observed, indicating that epicuticular wax content had positive effect on improving the drought resistance of barley.