雌雄组合模式下青杨形态和生理特征对干旱的响应差异

Different Morphological and Physiological Responses of Populus cathayana to Drought Under Male and Female Combination Mode

为了探究雌雄组合模式下青杨形态和生理特征对干旱的响应差异,本实验以青杨Populus cathayana雌雄植株为材料,在雌雄组合模式下进行干旱处理,比较干旱胁迫处理与对照处理中青杨植株的株高、基径、总叶片数、净光合速率、瞬时水分利用效率以及叶片水势等形态和生理指标,以探究雌雄青杨抗旱能力的差异。结果显示:雌雄组合模式下,干旱胁迫组植株的株高、基径、光合速率、气孔导度、蒸腾速率以及水势均显著下降,下降率分别为39.95%、33.51%、54.33%、67.52%、69.43%和353.45%;雌雄植株的株高、基径、总叶片数、气孔导度、蒸腾速率、胞间二氧化碳速率、细根/总根、水分利用率以及水势对干旱胁迫并未表现出显著的性别响应差异,但雌株在株高、基径、总叶片数和光合速率等方面下降的幅度均明显大于雄株。结果表明,干旱胁迫显著影响了合栽模式中雌雄植株的形态和生理变化,且干旱胁迫对青杨雌雄合栽模式下雌株的形态生长和生理过程的负面影响大于雄株,该结果为揭示雌雄组合模式下青杨雌雄异株植株对干旱的性别响应差异有重要参考意义。

Populus cathayana,a dioecious plant,is used as experimental materials to explore the different morphological and physiological characteristics responses of P.cathayana to drought in male and female combination mode.The difference of drought resistance between male and female poplars is discussed by comparing morphological and physiological indexes of P.cathayana in male and female combinaton model under drought stress management and control treatments,including plant height,basal diameter,photosynthetic rate,water use efficiency,leaf water potential and so on.The results show that the plant height,basal diameter,photosynthetic rate,stomatal conductance,transpiration rate and water potential under drought stress management have significantly decreased by 39.95%,33.51%,54.33%,67.52%,69.43% and 353.45%.Although there are no significant sexual differences in plant height,basal diameter,total leaf number,stomatal conductance,transpiration rate,intercellular carbon dioxide rate,fine root/total root,water utilization rate and water potential under drought stress management,the decreased-amplitude of female plants in plant height,basal diameter,total leaf number and photosynthetic rate is significantly greater than that of males in male and female combination mode.These results indicate that the morphological and physiological changes of male and female plants are significantly affected by drought stress management in male and female combination mode and the negative effects of drought stress management on morphological growth and physiological process of females are greater than that of males.The results are of important referencial significance for revealing the different sexual responses of dioecious poplar plants to drought in male and female combination mode.