小麦突变体返白系返白机理的研究 Ⅰ 返白阶段叶绿体超微结构观察

在返白系小麦叶色由绿变白的过程中,叶绿体结构发生退化。返白初期,出现大量的嗜饿小滴,基粒排列混乱,垛叠层数异常增多或减少,并且发现类囊体有肿大量的嗜胀现象,粒消失。返白中期,叶绿体中呈现空化现象,内部结构逐渐解体。到叶片继而,基全白时期,整个叶绿体变为低电子密度的囊泡状结构。在叶片由自复绿的过程中,叶绿体的这些变化又可逆转,内部结构又重现,基粒迅速形成,排列也较规则,整个叶绿体结构很快恢复正常。在整个返白阶段中,叶细胞中的其它内部结构如中央大液泡等也发生了一定的变化。

Studies on the Albescent Mechanism in the Mutant Stage Albinism Line of the Winter Wheat'' I. Observation of the Ultrastructure of Chloroplast during Albescent Stage

The changes took place in the chloroplast structural degeneration in the course of the mutant leaf color turning from green to white. At the early stage of the albescent process, numerous osmiophilic globules appeared, grana arrangement in the mutant chloroplast became disorder, and the numberof stacks in each granum changed......abnormally increased or decreased, andthylakoid in the grana became swelled. At the middle stage of the albescent process, some cavities could be observed in the chloroplast, and the interior structure of the chloroplast was gradually decomposed. At the white leaf stage, the whole structure of the cholorplast changed to a vesicle with low electronic density. However, it was found that these alternations could be reverse in the process of the white leaves turning into the green ones. And the interior structure reappeared, grana formed rapidly and arranged in order, and the whole structure of chloroplast renewed normally. Meanwhile, some changes in the interior structure such as the central sap vesicle in the leaf cells took place during the albescent stage.