干旱胁迫对金太阳杏叶绿素荧光动力学参数的影响

以2年生金太阳杏(ArmeniacavulgarisLam.)叶片为试材,采用田间试验的方法,设置4种土壤水分处理(土壤相对含水量为76%、65%、53%、45%),以正常供水为对照(CK),研究土壤干旱胁迫对叶绿素含量、叶片相对含水量及叶绿素荧光参数的影响。结果表明(1)胁迫条件下,基础荧光(Fo)略微上升,最大荧光(Fm)、可变荧光(Fv)、PS潜在活性(Fv/Fo)、原初光能转化率(Fv/Fm)、叶绿素含量(CHL%)、叶片相对含水量(LRWC)等值下降。(2)叶绿素荧光参数间相关性随土壤相对含水量的下降而逐渐减弱,正常供水条件下,2/3以上荧光参数相关性达显著水平;胁迫至后期(土壤相对含水量为45%),仅1/3显著相关。(3)Fm、Fv、Fv/Fo、LRWC与抗旱性综合评定指标Y始终存在显著相关性,可作为杏树抗旱性评定指标,参与抗旱品种的筛选。

Effect of soil drought stress on characteristics of chlorophyll fluorescence in Jintaiyang apricot variety

The field experiment was conducted with the leaves of 2-year-old Jintaiyang apricot(Armeniaca vulgaris Lam.)under four soil moisture treatments (with relative water content of 76%, 65%, 53% and 45%, respectively) to study the effects of drought stress on chlorophyll content, characteristics of chlorophyll fluorescence and relative water content of leaves (LRWC)by using SPAD-502 portable chlorophyll meter and Plant Efficiency Analyzer (PEA). The results were as follows:(1)Minimal fluorescence (F_o) slightly increased, but chlorophyll content, relative water content of leaves, maximal fluorescence (F_m), variable fluorescence (F_v), PS II latent activity (F_v/F_o), original light energy transforming rate (F_v/F_m), chlorophyll content and LRWC decreased under water stress. (2) The correlative analysis indicated that with the decrease of soil relative water content, correlation among chlorophyll fluorescence parameters lowered. Two thirds of the correlation coefficients reached significant level under normal watering (CK), and one third of them reached significant level when soil relative water content decreased to 45%. (3) There existed always significant correlation between F_m, F_v, F_v/F_o, LRWC and the integrated assessment index (Y), so they might be regarded as important indexes in assessing the drought-resistance of apricot varieties.