毛白杨花粉败育过程中淀粉和脂类的异常分布变化

Abnormal Changes of Polysaccharides and Lipids Distribution during Pollen Abortion in Populus tomentosa Carr

对毛白杨雄性可育无性系1319以及不育雄株BM-1花药发育过程中营养物质的分布和转化过程进行观察,结果表明:可育花药中,淀粉粒出现于小孢子母细胞时期的花药壁及小孢子母细胞内;到四分体时期,四分体外围、绒毡层内表皮以及花药表皮和内壁间开始积累脂类,药壁内淀粉含量减少;初生小孢子时期,绒毡层细胞开始退化,绒毡层细胞以及初生小孢子外壁积累大量脂类物质;成熟花粉时期,绒毡层完全降解,但绒毡层细胞残迹内仍有大量脂类物质积累,花粉表面完全被脂类包围,花粉内含少量淀粉粒。与可育花药相比,不育花药中药壁组织以及药室内脂类物质的合成量很少,花粉大多干瘪异常,无明显的脂类物质分布。上述结果说明脂类物质的匮乏以及营养物质的代谢紊乱是毛白杨花粉败育的原因之一。

We investigated the distributions of polysaeeharides and lipids during the anther development of Populus tomentosa Carr. male fertile clone 1319 and sterile stub BM-1. In fertile anthers, only polysaccharides depositions are at the micro- spore mother cells and anther wall. At the tetrad stage, ]ipids begins to accumulate around the tetrad on the endoscopic wall of tapetum cells and between the endothecium and epidermis. And then the tapetum begins to degenerate, and there are many lipids in degenerating tapetal cells and the microspore periphery. At the mature pollen stage, the tapetum degen- erates completely and the tapetal residue becomes massy lipids. There are a few polysaccharides in pollen and lots of lipids accumulated in pollen surfaee. Compared with its counterpart, there is no obvious lipids synthesis during the whole anther development process of BM-1. Therefore, the abnormal synthesis and distribution of polysaccharides and lipids is one of the reasons for pollen abortion of P. tomentosa Carr.