乌桕秋叶转色前后生理特性及超微结构的变化

以不同叶色乌桕叶片为试验材料,研究了秋季变色前后色素质量分数、碳水化合物及叶绿体超微结构的变化。结果表明:乌桕秋叶转色后,总叶绿素质量分数和叶绿素a质量分数显著降低;黄叶中类胡萝卜素质量分数大幅升高,而花色素苷质量分数与绿叶的差异不显著;红叶在叶绿素质量分数降低的同时,花色素苷质量分数极显著升高。乌桕秋叶在变色后氮元素、葡萄糖和淀粉质量分数均显著降低;黄色秋叶中果糖和蔗糖质量分数降低,而在红色秋叶中果糖和蔗糖质量分数则有所升高。转色后,叶绿体结构松散,甚至解体;叶绿体内淀粉粒减少,嗜锇颗粒增多。

Changes in Physiological Index and Chloroplast Ultrastructure in Fall Foliage of Sapium sebiferum Before and After Leaf Color Change

An experiment was conducted to study the variation in pigment content,related carbohydrate and chloroplast ultrastructure in Sapium sebiferum leaves of different colors after turning yellow or red in fall.Results showed that the contents of total chlorophyll and chlorophyll-a decreased significantly with leaf color changing,the carotinoid contents increased largely,while the anthocyanin contents changed little in the yellow leaves as compared with the green ones.In the red leaves,the decreased chlorophyll contents were accompanied by a significant increase in anthocyanin contents.The contents of nitrogen,glucose and starch in the leaves decreased significantly after leaf color change.The contents of fructose and sucrose reduced in yellow leaves,while increased in red leaves.After leaf color change,chloroplast structure became loose or even disintegrated,and starch grain decreased,while osmiophilic granules increased.