黄瓜和黑籽南瓜对肉桂酸及亚低温交叉胁迫的应答差异

Study on different responses to cinnamic acid and sub-low temperature stress on cucumber and figleaf gourd seedlings

为探索肉桂酸(Cinnamic acid,CA)和亚低温交叉胁迫对黄瓜和黑籽南瓜生理代谢的影响,对两种瓜类作物的水分代谢与光合作用受到CA及亚低温交叉胁迫的应答差异进行研究。结果表明:CA和亚低温单独胁迫降低了叶片的总含水量、自由水含量、自由水/束缚水、净光合速率(PN)、蒸腾速率(Tr)和气孔导度(gs),提高了叶片的渗透势;抑制了根系干物质的分配比例,增加了地上部干物质的分配比例;增加了瞬时水分利用效率(WuE)和潜在水分利用效率(WuEi),抑制了叶面积(LA)的生长速率。CA和亚低温交叉胁迫对2种作物生理活动的影响与其单独胁迫一致,交叉胁迫的影响最大,其次是亚低温单独胁迫,CA单独胁迫影响最小,黄瓜受到胁迫的程度明显高于黑籽南瓜。总之,CA和亚低温交叉胁迫对黄瓜的毒害较单一因子明显,黄瓜抵御CA和亚低温胁迫的能力明显低于黑籽南瓜。

The responding differences of water metabolism and photosynthesis to CA and sub-low temperature were studied in cucumber and figleaf gourd seedlings.CA and sub-low temperature individually decreased total water content in leaf,free water content in leaf,bound water content in leaf,free water content/bound water content,net photosynthetic rate(PN),transpiration rate(Tr)and stomatal conductance(gs),however increased osmotic potential in leaf in both species.CA or sub-low temperature deduced dry matter content in root and leaf area(LA),but increased in shoot,instantaneous water use efficiency(WuE)and potential water use efficiency(WuEi)in leaf of cucumber and figleaf gourd.Effects of CA and sub-low temperature stress on two species were consistent with that of CA or sub-low temperature.However,effects of CA and sub-low temperature cross stress on physiological mechanism were most obvious in both cucumber and figeaf gourd,followed by sub-low temperature,and finally CA,in addition,CA and sub-low temperature was much more harmful in cucumber than figleaf gourd.