干旱胁迫对猕猴桃叶片及光合作用的影响

Effects of Drought Stress on Leaves and Photosynthesis of Kiwifruit

为探明猕猴桃在生长期对干旱胁迫的响应机制,以嫁接三年生“翠玉”猕猴桃为试材,调查研究了4个不同程度的干旱胁迫对猕猴桃叶片叶绿素含量、叶片光合指标、叶片生理性状及农艺性状的影响。结果表明:随胁迫程度的加深与胁迫时间的延长,猕猴桃叶片的叶绿素相对含量、净光合速率、蒸腾速率、干物质含量、失水率值均下降,叶片长宽比、叶面积均降低,猕猴桃叶片的受害率、叶片厚度有显著增加,抗坏血酸中在中度干旱胁迫也有显著增加。通过盆栽模拟干旱胁迫表明,猕猴桃植株在轻度干旱胁迫下可以一直维持基本生长需求,一旦胁迫超过轻度干旱胁迫后出现叶片黄化枯萎、脱落,而重度干旱胁迫15d则会出现各项指标降低。

In order to explore the response mechanism of kiwifruit to drought stress during the growth period,the effects of four different degrees of drought stress on chlorophyll content,photosynthetic index,and physiological traits of kiwifruit leaves,as well as agronomic traits were investigated by using grafted three-year-old"jade"kiwifruit as test materials.The results show that with the deepening of stress degree and the extension of stress time,the relative chlorophyll content,net photosynthetic rate,transpiration rate,dry matter content,and water loss rate of kiwifruit leaves all decrease,and the ratio of leaf length-to-width and leaf area all decrease.The damage rate and thickness of kiwifruit leaves increase significantly.Ascorbic acid also increases significantly under moderate drought stress.The results of simulated drought stress in pots show that kiwifruit plants can maintain their basic growth requirements under mild drought stress,and once the stress exceeds the mild drought stress,the leaves begin to become yellow,wither,and fall off,while the indicators decrease after 15 days of severe drought stress.