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作 者 ：王振兴1,艾 军1*,陈 丽2,范书田1,何 伟1,秦红艳1,赵 滢1

期 刊 ：西北植物学报 2015年 2期 页码：329~334

关键词：软枣猕猴桃；高温胁迫；光系统；JIP-test；

Keywords:Actinidia arguta (Sieb.et Zucc.) Planch.ex Miq., heat stress, photosystem, JIP-test,

摘 要 ：以软枣猕猴桃“魁绿”为试验材料,利用快速叶绿素荧光诱导动力学曲线分析技术(JIP-test)研究了热胁迫处理对植株叶片光系统Ⅱ活性的影响。结果显示:(1)软枣猕猴桃叶片最大光化学效率(F_v/F_m)在35～48 ℃的范围内并没有明显变化,只有当温度升高到52 ℃时才显著下降。(2)随着温度升高,叶绿素荧光诱导动力学曲线中J点和I点的相对可变荧光V_j和V_i呈显著下降趋势,在52 ℃又显著升高,而K点的相对可变荧光V_k则逐渐上升;叶片捕获的激子将电子传递到电子传递链中Q_A^-下游电子受体的概率(ψ₀)随着温度升高而逐渐上升,但在52 ℃时显著下降。(3)随着热胁迫时间的延长,V_j和V_i随时间延长而升高,ψ₀则下降,电子传递链受体侧受到了严重的抑制。研究表明,高温显著抑制了软枣猕猴桃叶片PSⅡ电子传递链供体侧和受体侧的活性,但PSⅡ的供体侧比受体侧对高温更加敏感;JIP-test测定的相关参数能有效地评价不同温度对软枣猕猴桃光系统活性的影响。

Abstract:The effects of heat stress on activities of photosystem Ⅱ in leaves of Actinidia arguta (Sieb.et Zucc.) Planch.ex Miq.(Kuilü,a cultivar) were studied by chlorophyll a fluorescence transient and JIP-test.The results showed that:(1)F_v/F_m of leaves did not significantly change at 35-48 ℃,but decreased at 52 ℃.(2)With increase of leaf temperature,the relative variable fluorescence at J and I steps of fluorescence transient (V_j and V_i) significantly decreased,but increased at 52 ℃,the relative variable fluorescence V_k increased gradually.(3)With the increase of heat treatment time,the V_j and V_i increased gradually,but Ψo decreased gradually,indicating that the acceptor side of PSⅡ was damaged severely.In summary,activity of the donor side and the acceptor side of PSⅡ was inhibited by high temperature.The donor side was more sensitive to heat stress.JIP-test parameters can evaluate effectively activity of photosystems Ⅱ in leaves of A.arguta under different temperatures.

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