小麦突变体返白系返白阶段叶绿体超微结构变化研究

分别采取返白系返白前期(全绿苗)、返白中期(全白苗)和复绿苗5个不同叶龄叶片,通过电镜系统观察了各叶龄叶片的叶绿体超微结构,结果表明,返白过程中,返白系幼叶中的幼龄质体发育停滞于前质体阶段,随着叶龄增加,已发育的质体体积虽有一定程度增大,但质体内部结构不能形成甚至退化;复绿过程中,幼叶中的质体恢复发育,叶龄较大的叶片中(如全卷叶)存在着发育程度不同的质体,小的质体可能恢复发育,最终导致叶片复绿,而较大的质体则空化。说明返白过程中幼龄质体发育停滞,或已发育的部分质体内部结构退化是叶片白化的原因,停滞发育的前质体恢复发育是复绿的主要细胞学特征。

Studies on the Chloroplast Ultrastructure of ＂Stage Albinism Line the Winter Wheat＂(SA) Mutant During the Albescent Period

The chloroplast ultrastructure of 5 defferent developping leaves of SA were researched by electron-microscopic observation during before albescent period,medarate albesceng period and regreen period respectively.The rusults were as follows:in albescent period,the underdeveloped plastids of the very young leaves stopped at the etoplastid stage,the volume of the developed plastids in young leaves expanded at an extent with the leaves growing,but their intenal ultrastucture didn''t form or degrenerate; during regreen period,the plastids in young leaves redeveloped,there were the defferent developing plastids in the older leaves(such as all-rolled leaves),the smaller plastids might redevelop so that the leaves were regreen,but the bigger plastids destroyed.This indicated that it was because the young plastids stopped and the internal ultrastucture of some developed-plastids destroyed in the albescent period that the leaves of SA turned albescent; it was the regreen cytological characteristic of leaves that the etoplastids stopping development redeveloped.