干旱胁迫下抗蒸腾剂对叶子花生理特性的影响

Effects of antitranspirant on physiological characteristics of Bougainvillea spectabilis under drought stress

为了探讨干旱条件下不同浓度抗蒸腾剂对叶子花光合作用及抗氧化响应影响的生理机制,分别对叶子花喷施清水、400倍稀释、800倍稀释和1 200倍稀释的抗蒸腾剂,以正常管理作为对照组,在自然干旱条件下连续处理21 d。结果表明:与单一干旱胁迫相比,抗蒸腾剂降低了叶子花的气孔导度和蒸腾速率,使其保持相对较高的净光合速率和稳定的胞间CO_2浓度。同时,抗蒸腾剂还可以有效缓解干旱胁迫下叶子花叶绿素含量和相对含水量的下降,减缓电解质渗透率和丙二醛含量的上升,进一步提高SOD,POD,CAT和APX的活性及脯氨酸含量,从而提高叶子花的抗旱性。其中,喷施800倍稀释的抗蒸腾剂对提高叶子花抗旱能力效果最为显著。

To investigate the effects of antitranspirant with different concentration on photosynthesis and antioxidant responses of Bougainvillea spectabilis under drought stress, the plants were treated for 21 days under natural drought condition after applying water and 400, 800, 1200 times dilution antitranspirant as a foliar spray, and the plants un- der normal culture condition were set as the control group. The results showed that antitranspirant reduced the stoma- ta[ conductance and transpiration rate, maintained a relatively higher net photosynthetic rate and a stable intercellular CO2 concentration in Bougainvillea spectabilis when compared with single drought stress. Moreover, antitranspirant could alleviate the loss of chlorophyll content and relative water content, reduce the increase of electrolyte leakage and malonaldehyde content, and further improve the activities of SOD, POD, CAT and APX as well as proline con- tent in Bougainvillea spectabilis under drought stress. These results indicated that antitranspirant could enhance the resistance to drought stress of Bougainvillea spectabilis, and the best concentration was the antitranspirant with 800 times dilution.