水分胁迫下柚木叶绿素荧光动力学特性

Chlorophyll Fluorescence Parameters of Tectona grandis in Water Stress

以柚木(Tectona grandis)1年生苗为材料,对柚木盆栽苗自然干旱胁迫下叶绿素、荧光参数等进行了研究。结果表明:水分胁迫引起柚木相对叶绿素含量下降,随着水分胁迫的加剧,其荧光参数的变化规律不同,柚木的Fo(初始荧光)值总体呈上升的趋势;Fm(最大荧光)和Fv(可变荧光)值呈持续下降的趋势,Fv/Fm(PSII最大光化学量子产量)、Fv/Fo(PSII潜在活性)和Fm/Fo(PSII捕获激发能的效率)值呈升-降的变化趋势。表明柚木在一定水分胁迫时间内,其光能转换效率没有受到影响,之后才被抑制,光合作用下降,PSⅡ利用光能的能力下降,PSⅡ捕获激发能和PSⅡ的潜在活性的效率最终抑制。

Using one-year-old Tectona grandis seedlings as materials, chlorophyll, fluorescence and oth- er indexes of potted seedlings under natural drought stress condition were studied. The results showed that water stress caused decline of relative chlorophyll content. As water stress was aggravated, variation law of fluorescence was different. Fo value showed upward trend. Fm and Fv values were in decreasing trends. Fv/Fm, Fv/Fo and Fm/Fo were in trends from upward and downward. It showed that in a certain peri- od of water stress, the light-energy conversion efficiency was not affected, but was restrained later. Pho- tosynthesis declined. The ability of PS Ⅱ to use photosynthesis reduced. Lateral reactivity and capturing excitation energy efficiency of PS Ⅱ were restrained.