低温弱光胁迫对设施黄瓜叶片形态变化的影响

Effects of low temperature and weak light stress on leaf morphological changes of cucumber in greenhouse

【目的】研究低温弱光对黄瓜叶片形态性状的影响,进而为设施黄瓜作物生长环境监控提供理论依据。【方法】以黄瓜品种“碧玉3号”为试材,设施无土栽培试验研究低温弱光胁迫对黄瓜叶面积、叶干物质量等叶片形态的影响,探讨不同叶序的叶面积、叶干物质量随低温弱光胁迫的变化规律。【结果】低温弱光胁迫导致叶片的叶面积、干物质量均有不同程度下降,其中,植株中下部的叶片叶面积下降较为显著(最大降幅约40.3%),而植株中上部的叶片干物质量下降较为显著(最大降幅约20.6%)。轻、中度低温胁迫(温度为10~20℃)导致紧邻植株中部位置的叶片叶面积明显比处于植株两端的叶片叶面积更大,而重度低温胁迫(温度为5~10℃)对不同叶序叶片形态变化影响较小且彼此差异不明显。弱光胁迫下叶片叶面积随叶序变化较大,而当光量子通量密度(Photosynthetic photon flux density,PPFD)一定时叶片干物质量随叶序变化较小。【结论】低温弱光胁迫对黄瓜植株中下部叶片形态影响较大,轻度低温胁迫不仅没有影响黄瓜叶片形态发育,还有利于植株中部叶片的光合生产与同化物转化。

【Objective】The present paper aimed to study the effects of low temperature and weak light on the morphological characteristics of cucumber leaves,which provided a theoretical basis for monitoring the growth environment of greenhouse cucumber crops.【Method】The effects of low temperature and low light stress on the leaf area,dry matter quality and other morphological characters of cucumber by soilless cultivation experiment in greenhouse with‘Biyu 3’as tested materials were studied,and the change rules of leaf area and dry matter quality of different leaf order with low temperature and weak light stress were discussed.【Result】Low temperature and weak light stress led to different degrees of decline in leaf area and dry matter mass.Among them,the leaf area of the middle and lower parts of the plant decreased significantly(the maximum decrease rate was 40.3%),while the dry matter mass of the middle and upper leaves of the plant decreased significantly(the maximum decrease rate was 20.6%).Under mild and moderate low temperature stress(10-20℃),the leaf area near the middle part of the plant was significantly larger than that at both ends of the plant.However,severe low temperature stress(5-10℃)had little effect on the morphological changes of different leaf orders,and there was no significant difference between them.Leaf area changed greatly with leaf order under low light stress,while leaf dry matter mass changed little with leaf order when PPFD was constant.【Conclusion】Low temperature and weak light stress had a great effect on the morphology of the middle and lower leaves of cucumber plants.Mild low temperature stress not only did not affect the morphological development of cucumber leaves,but also was conducive to the photosynthetic production and assimilate transformation of the middle leaves of cucumber plants.