阿克苏市5个枣引种品种叶绿素荧光特征比较

测定比较了阿克苏市5个枣引种品种的初始荧光(Fo)、最大荧光(Fm)、PSⅡ最大光能转化效率(Fv/Fm)和PSⅡ最大光能转化潜力(Fv/Fo)4个叶绿素荧光参数随太阳总辐射、空气温度和空气相对湿度变化的日变化以及不同作用光强下从初始荧光上升到最大荧光一半所需时间(T1/2)的变化特征.结果表明:5个枣品种的叶绿素荧光参数Fv/Fm、Fv/Fo、Fo、Fm的品种间差异均达到了极显著水平(P＜0.001),而且在时间序列上Fv/Fm、Fv/Fo、Fo和Fm也均表现为差异极显著(P＜0.001);骏枣、金丝小枣的Fv/Fm值全天保持较高水平,灰枣、赞皇大枣的Fv/Fm日均值处于较低状态,且赞皇大枣的Fv/Fm和Fv/Fo日均值显著低于其它品种;除骏枣、金丝小枣的叶绿素荧光参数T1/2下午相比上午变化不是很明显外,其它品种均有不同程度的降低,表明下午的强光、高温和低空气湿度使得PSⅡ活性下调,PSⅡ光合电子传递链受阻,从而发生了光抑制.测试品种耐光抑制能力的强弱为:骏枣耐光抑制能力最强,金丝小枣、羊角枣其次,灰枣、赞皇大枣耐光抑制能力最弱.

Comparison on Chlorophyll Fluorescence Characters in Five Introduced Jujube Varieties in Aksu City

Diurnal variation of four chlorophyll fluorescence parameters including initial fluorescence(Fo),maximal fluorescence(Fm),maximal efficiency of primary conversion of light energy of PSⅡ(Fv/Fm),maximal potential of primary conversion of light energy of PSⅡ(Fv/Fo) along with variation of three environmenu factors including solar radiation,air temperature,air relative humidity and character of T1/2 under different actinic intensity in five introduced jujube varieties in Aksu city were determined and compared.The results were shown as follows: There were extremely significant differences in Fv/Fm,Fv/Fo,Fo and Fm(P<0.001)among the five introduced jujube varieties.The differences in Fv/Fm,Fv/Fo,Fo and Fm were extremely significant(P<0.001)on the level of time series.The value of Fv/Fm of Ziziphus jujuba 'Junzao' and Ziziphus jujuba 'Jinsixiaozao'were kept on a higher level.The value of Fv/Fm of Ziziphus jujuba 'Huizao',Zizyphus jujuba 'Zanhuangdazao' retained on a lower level during the whole diurnal variation process and the average of Fv/Fm and Fv/Fo of Z.jujuba 'Zanhuangdazao' was obviously lower than that of the others.Except T1/2 of Z.jujuba 'Junzao' and Z.jujuba 'Jinsixiaozao' was not evidently varied at p.m.compared with the same value at a.m.,T1/2 of the other varieties decreased to some certain extent,indicating that photosynthetic activity decreased and PSⅡelectron transport was inhibited after strong irradiance,high air temperature and low air relative humidity,which led to light inhibition.The extent of ability to resist light inhibition of experimented varieties was: Z.jujuba 'Junzao' was the strongest,Z.jujube 'Jinsixiaozao' and Ziziphus jujuba 'Yangjiaozao' was the middle,Z.jujuba 'Huizao' and Z.jujuba 'Zanhuangdazao' was the weakest.