玉米不同叶位叶片叶绿体超微结构与光合性能的研究

对玉米植株基部（第3叶），中部（果穗叶）和上部（倒2叶）叶位叶片，进行叶绿体超微结构的观察，并测定了叶绿素含量和光合强度，结果表明，不同叶位叶片叶肉细胞中叶绿体的超微结构，随叶位上升而渐趋复杂化，果穗叶最为显著，向上又趋简单，具体表现为基粒片层的数目随叶位上升而增多基质片层和基质也随之增加，果穗叶最多，向上又趋减少，不同叶位叶片叶绿素含量和光合强度，果穗叶高于其它叶位。

ULTRASTRUCTURE OF CHLOROPLAST AND PHOTOSYNTHETIC PROPERTIES OF THE LEAVES AT DIFFERENT POSITION IN MAIZE

The leaves at the different position,the basal,the middle and the upper,were examined with TEM.The content of chlorophyll and photosynthetic rate in those leaves was measured. The ultrastructure of chloroplast varies with the different position of leaves.The amount of grana lamellae,stroma lamellae and stroma increased generally with the rising position of leaves.That of the ear leaf at the middle position,was the highest than that of the others.In the upper leaf,the amount of grana lamellae,stroma lamellae and stroma was reduced.Also, the content of chlorophyll and the photosynthetic rate in the ear leaf was higher as compared with that is the other positional leaves. The observations revealed that the tendency of the variation in ultrastructure of the leaves at different position was in conformity with photosynthetic properties.The ultrastructure and function of ear leaf were better than that of other leaves.