棉花胚珠纤维细胞分化的研究——纤维细胞初期发育阶段超微结构观察

Ultrastructure of Early Stages of Cotton Fiber Differentiation

以陆地棉北农-1号(BN-1)和光籽突变种(MXZ-142)为材料,超薄切片透射电镜(TEM)连续观察开花前2天至开花后后2天的胚珠表皮细胞超微结构的变化,从解剖学上观察研究胚珠表皮细胞的分化发育。开花前后 BN-1胚珠表皮纤维原始细胞发生一系列显著变化:开花前,表皮细胞中各种细胞器含量较不丰富,没有细胞突起。开花当天纤维原始细胞突起,细胞核增大,线粒体、高尔基体、内质网增多,部分胞间连丝消失。亮、暗两类细胞均可突起成纤维细胞,暗细胞是液泡内酚类物质弥散至胞质所致。MXZ-142胚珠表皮细胞变化相应较小,与BN-1未突起的细胞相似,胞间连丝未见消失,没有表皮毛细胞的分化突起。本文还讨论了棉花胚珠表皮纤维细胞的分化机理。

Fine structure of the outer epidermal layer of cotton ovules in Gossypium Hirsutum.L.BN-1 and fiberless mutant MXZ-142 was examined from 2 days preanthesis to 2 days postanthesis.During the period,BN-1 ovule epidermal differentiating cells have changed sharply.Before anthesis,the cell organelles in the epidermal cells are not rich,and no fiber cell protrued At anthesis,differentiating primordical fiber cells elongate.The nucleus of the cell enlarged,Mitochdrion,dictyosome and rough edoplasmic reticulum appeared more numerous than in adjacent non-differentiating epidermal cell. Plasmodesmata in the foot of elongation cell disappeared.The protrusive cell is bright or dark,MXZ-142 ovule epidermal cell have no differentiating cell. The homges of the cells are similar go the BN-I nondifferentiating cells.And the plasmodesmata havent disappeared.No fiber cell differentiated,