The uniformity of chloroplast grana lamellae,, the numbers and cristae of mitochondria, and the concentration of nucleus karyolymph were different among different mature grade leaves.

• 不同成熟度叶片超微结构变化明显，主要表现在叶绿体片层结构整齐程度、线粒体个数和嵴数以及细胞核核液浓度上。