泡桐黄化突变体生理特性分析

【目的】分析泡桐黄化突变体的生理特性,为泡桐新品种的研究及应用提供理论参考。【方法】将新发现的泡桐黄化突变体(PFE)与白花泡桐(PF)、建始泡桐(PJ)、楸叶泡桐(PC)的生理特征进行比较,分析了其光合色素的含量、光合日变化、抗氧化酶活性及丙二醛含量。【结果】黄化突变体的叶绿素a、叶绿素b、总叶绿素、类胡萝卜素含量减少,其中叶绿素b显著减少; 黄化突变体的净光合速率和蒸腾速率总体小于其他种,气孔导度值与其他种相比总体降低,但差异较小,胞间CO₂浓度日变化值均高于其他种; 泡桐黄化突变体的SOD、POD、CAT活性和丙二醛(MDA)含量均高于其他种。【结论】光合色素的减少是导致叶色黄化的主要原因; 它影响了植株捕光能力,致使净光合速率下降,抗氧化酶活性增强,植株抗性增加,可减少活性氧对植株的伤害,维持植物正常生长。

Physiological characteristic analysis of etiolation mutant in Paulownia fortnnei

[Objective] Analyze the physiology of Paulownia fortunei etiolation,in order to establish a theoretical basis for researching new Paulownia varieties.[Method] The photosynthetic pigment content,photosynthetic diurnal changes,antioxidant enzyme activity and MDA content of P.fortunei,P.jianshiensis,P.catalpifolia,and a recently discovered P.fortunei etiolation mutant were analyzed.[Result] The chlorophyll a,chlorophyll b,total chlorophyll and carotenoid levels of the mutant were reduced,with that of chlorophyll b reduced remarkably.Diurnal variation in the photosynthetic rate and transpiration rate of the etiolation mutant was generally lower than that of the other species.However,there was no significant difference among the stomatal conductance of the mutant and species,and its value generally decreased.Meanwhile,antioxidant enzyme activity,MDA content and diurnal variation in intercellular CO2 concentration were higher in the etiolation mutant than in the other species.[Conclusion] Reduced photosynthetic pignent contents were the main cause of leaf yellowing,which impedes light harvesting and photosynthesis,enhances the activity of antioxidant enzymes,increases plant resistance,reduces the damage of active oxygen,and maintains normal plant growth.