叶绿素荧光仪饱和脉冲光作用前后温州蜜柑叶温的变化

Changes of Citrus unshiu Marc.leaf temperature as affected by saturation pulse light of chlorophyll fluorescence apparatus

用营养液培养的方法,研究了叶绿素荧光仪3000μmol.m-2.s-1饱和脉冲光对不同磷水平和光照处理的温州蜜柑(Citrusunshiu Marc.)叶温的影响。结果表明:饱和脉冲光作用前后,缺磷强光组(-P900)、缺磷中强光组(-P600)和缺磷弱光组(-P100)的叶温差(△t)依次升高,并且培养光强越弱,处理时间越长,升高幅度越大;而供磷强光组(+P900)、供磷中强光组(+P600)和供磷弱光组(+P100)之间,△t无明显差异;用二硫苏糖醇(DTT)处理后,无论缺磷与否,各处理组之间△t差异显著;△t的日变化随光强的升高而增大;各组叶绿素a、叶绿素b和类胡萝卜素含量均随培养光强的升高而下降,而蒸腾速率、气孔导度和胞间CO2浓度差异不大;说明温州蜜柑叶温差与光强、磷水平、DTT处理和缺磷胁迫时间有关。

By using solution culture, this paper studied the effects of 3 000μmol.m^-2.s^-1 saturation pulse light of chlorophyll fluorescence apparatus on the leaf temperature of Citrus unshiu Marc. under different phosphorus supply and light intensity. The results showed that after treated with the saturation pulse light of chlorophyll fluorescence apparatus, the leaf temperature difference （△t） of C. unshiu increased in the sequence of phosphorus deficiency blaze group （ - P900 ）, phosphorus deficiency mid-blaze group （ - P600 ）, and phosphorus deficiency low-light group （ - P100）. A wider rising scope was observed with the weaker intensity of culture light and longer processing time. On the contrary, there was no significant difference in △t among the phosphorus supply blaze group （ ＋ P900）, phosphorus supply mid-blaze group （ ＋ P600 ）, and phosphorus supply low-light group （ ＋ P100 ）. When 1,4-dithiothreitol （DTT） was applied, the difference of △t among the groups became remarkable whether phosphorus was supplied or not. The diurnal changes of △t increased with increasing light intensities. The contents of chlorophyll a, chlorophyll b and carotenoid of each group decreased with increasing light intensity, while the transpiration rate, stomatal conductance and intercellular CO2 concentration had less difference among the groups. This study suggested that the leaf temperature difference of C. unshiu was related to light intensity, phosphorus supply, processing with DTT, and duration of phosphorus deficiency stress.