干旱胁迫对杉木无性系叶绿素荧光特性的影响

Effects of drought stress on chlorophyll fluorescence characteristics of Chinese fir clones

研究了PEG-6000模拟轻、中和重度干旱胁迫对杉木优良无性系5号和49号1年生幼苗的叶绿素荧光参数的影响。结果表明:干旱胁迫下,5号和49号杉木无性系的F_o值总体高于对照,轻度和中度胁迫下先上升后下降,重度胁迫下先下降后上升;最大荧光产量(F_m)、最大可变荧光强度(F_v=F_m-F_o)、最大光化学效率(F_v/F_m)、PSⅡ的潜在活性(F_v/F_o)总体呈下降趋势。5号无性系在轻度胁迫48和72 h时,F_m值分别比对照降低38.7%和48.7%,均与对照差异显著(P<0.05);5号无性系在轻度胁迫48 h时,F_v值与对照差异显著(P<0.05);49号无性系的F_m值及F_v值均不断降低,但与对照差异不显著。不同胁迫强度下,5号无性系的F_v/F_m值降低幅度均大于49号,5号无性系胁迫72 h时不同胁迫强度的F_v/F_o值均显著低于对照(P<0.05),49号无性系在重度胁迫48 h的F_v/F_o值与对照差异显著(P<0.05)。干旱胁迫下,49号比5号杉木无性系具有更强的光合调控能力,可为耐旱型优良杉木种源的筛选提供依据。

Using PEG-6000 simulating light,moderate and severe drought stress,the chlorophyll fluorescence parameters of the seedling of No.5 and No.49 one-year-old Chinese fir clone were analyzed.The results were as follows:for both No.5 and No.49 clones,the Fo value was higher than the control under all the stress treatments,Fo increased at first and then decresed under light and moderate treatments,while Fo decreased firstly and then went up under severe stress;the F m,Fv,Fv/F m and Fv/Fo generally decreased with stress increase.For No.5 clone,the F m value significantly decreased by 38.7%and 48.7%,respectively,compared to the control under 48 and 72 h light stress treatments(P<0.05);the Fv value significantly decreased compared to control under 48h light stress treatment(P<0.05).For No.49 clone,the F m and Fv value decreased compared to control,but there was not signifi cantly difference.Under all the stress treatments,the Fv/F m value was higher in No.5 clone than in No.49 clone.The Fv/Fo value was significantly lower in No.5 clone than control under 72 h stress treatment(P<0.05),and the Fv/Fo value was only significantly lower in No.49 clone than control under 48h severe stress treatment(P<0.05).In conclusion,under drought stress,the No.49 clone has stronger photosynthesis regulation ability than No.5,which can provide scientific guideline for screening superior drought tolerance clone of Chinese fir provenance.