摘要： 以软枣猕猴桃魁绿为试验材料,采用植物效率仪Pocket-PEA研究了不同胁迫处理对光系统活性的影响。结果表明:随着温度的升高,原初最大光化学效率(Fv/Fm)在35～48℃的范围内并没有明显变化,当温度升高到52℃时,则迅速下降。随着温度升高,相对可变荧光在K点的值(Vk)逐渐上升,而Vj和Vi则呈现逐渐下降,在52℃迅速升高,而在低温胁迫后Vk没有变化,Vj和Vi则呈现逐渐上升的趋势,叶片捕获的激子将电子传递到电子传递链中QA下游电子受体的概率(ψ0)随着温度升高而逐渐上升,但在52℃时,迅速下降,而在低温胁迫后ψ0显著下降,这说明高温引起电子传递链供体侧和受体侧受到伤害,但供体侧对高温更加敏感,而低温胁迫后供体侧基本没有受到伤害,而受体侧受到显著的伤害,说明受体侧对低温胁迫更敏感。

关键词: 高温胁迫, 低温胁迫, 光系统, 软枣猕猴桃

Abstract: The effects of different stress on photosynthetic activities of photosystem in leaves of Actinidia arguta(Seib.et Zucc.) Plangch.ex Miq.were studied by a portable fluorometer(PEA-Plant Efficiency Analyser).The results shown that Fv/Fm had not significant change at 35-48℃,but only at 52℃ there was a significant decrease.With increasing leaf temperature,the relative variable fluorescence Vk increased gradually and became significantly higher at 52℃.On the other hand,the relative variable fluorescence Vj and Vi had significant decrease at 48℃,but had significant increase at 52℃.Under low temperature Vk had no significant change,but Vj and Vi had significantly increased.Changes in the probability of that a trapped exciton the moves an electron further than QA(Ψ0) was contrary to Vj and Vi under heat stress,but Ψ0 had sinificantly decreased under low temperature.These data further confirm that both the donor side and the acceptor side of PSⅡ,especially the donor side,were more sensitive to heat stress,but the acceptor side of PSⅡwas more sensitive than the donor side under low temperature.

Key words: Heat stress, Low temperature stress, Photosystem, Actinidia arguta(Seib. et Zucc.), Plangch.ex Miq.

中图分类号: 

• S661.01