小麦叶片衰老的超微立体学研究及6-苄氨基嘌呤的作用

Stereological Changes of Chloroplast Ultrastructure and the Effects of 6-Benzylaminopurine during Wheat Leaf Senescence

用电子显微镜和立体学方法考察了自然条件下小麦叶片衰老过程中超微结构的立体学参数变化及6-苄氨基嘌呤(BA)的调节作用,结果表明;在叶片衰老过程中叶绿体的体积膨胀且由椭球形变为球形,其体密度、面密度和数密度均下降;基粒变小且失去严整性,类囊体膨胀,但每叶绿体中基粒的数目在衰老早期是增加的;BA能够维持叶绿体和基粒结构、形态的稳定,对各立体学参数均有一定影响。

The changes of chloroplast ultrastructure were investigated with electronic mi croscopy and stereological methods, and a series of geometry parameters during wheat flag leaf senescence were obtained. The results showed that during flag leaf senescence: (1) Chloroplast shape changed from oval into sphere; The volume, the surface and the number of chloroplast per unit cell volume decreased continuously; (2) Grana volume decreased and their integrity lost; Grana thylakoids swelled and were progressively dismantled; But grana number per chloroplast increased in the early senescence stage; (3) BA treatment could influence various stereological parameters of chloroplast ultrastructure. As a result, BA could preserved the stability of chloro plast shape and structure.