干旱胁迫对4个锦带花品种叶绿素及PSⅡ光化学活性的影响

摘要

为了明确干旱胁迫对四季锦带、红王子锦带、紫叶锦带和金叶锦带4个品种叶绿素质量分数和荧光参数的影响，采用田间持续干旱法，测定了各参数的变化曲线。结果表明：在干旱胁迫下，各品种叶绿素质量分数变化规律较一致，均呈不规则波动，其中四季锦带和金叶锦带、红王子锦带和紫叶锦带叶绿素质量分数曲线的变化趋势两两相似；胁迫显著降低了PSⅡ单位面积有活性反应中心数量RC／CSo、光化学性能指数PI，A，B，S值；荧光诱导曲线中K点相对可变荧光（Wk）和J点相对可变荧光（Vj）的值均较对照不同程度增加；暗适应下初始荧光Fo 值、PSⅡ最大光化学效率Fv／Fm 值均呈现下降趋势。总之，干旱胁迫下4个锦带花品种PSⅡ光化学活性受到不同程度的抑制，四季锦带对干旱的响应最强烈，其次是紫叶锦带和金叶锦带，红王子锦带最弱。%We explored the response of chlorophyll content and chlorophyll fluorescence parameter of four cultivated varieties of Weigela florida to the drought stress, and determined the change curve of each variety of the content of chlorophyll and chlorophyll fluorescence parameters by continuous drought in the field.The change rule of chlorophyll a, b, ( a+b) con-tents of various varieties was irregular.The change curve of Weigela florida cv.Red Prince and W.florida cv.Foliia Pur-pure showed rise-lower-rise, while W.florida Bunge A.DC and W.‘Red Prince’+vat showed“lower-rise”.The density of RC/CSo and PI,A,B,S of the various varieties significantly decreased compared with the control under drought stress.Wk and Vj increased compared with the control in the O-J-I-P chlorophyll fluorescence transients.Both Fo and Fv/Fm decreased compared with the control.The resistance drought ability of four cultivated variety were restrained to various degrees under drought stress, and the most obvious response to the drought stress was W.florida Bunge A.DC, followed by W.florida cv. Foliia Purpureis, W.‘Red Prince’+vat, and W.florida cv.Red Prince.