甘蓝型油菜光、温敏雄性不育系Huiyou50S花粉败育的细胞学观察

Cytological Observation of Anther Development of Photoperiod/Thermo-sensitive Male Sterile Line Huiyou50S in Brassica napus

Huiyou50S是从甘蓝型油菜品种汇油50中发现的半不育株选育而成的光、温敏雄性不育系,育性受隐性核基因控制,在高温、长光周期下不育而在低温、短光周期条件下可育。本文通过半薄树脂切片、扫描电镜、花粉压片染色、花药整体透明方法对Huiyou50S及其近等基因系Huiyou50F的花药发育过程及花粉形态观察比较。结果表明,Huiyou50S的花药造孢细胞、花粉母细胞、减数分裂、四分体阶段均正常,在单核期出现明显异常,虽然能形成花粉壁,但小孢子细胞质收缩、解体,最终只剩余空瘪的花粉壳;Huiyou50S的花药绒毡层在单核后期提前降解,绒毡层解体速度快于可育株Huiyou50F。Huiyou50S的小孢子的完全败育主要发生在单核时期,绒毡层发育与小孢子异常有某种关联,该结论为油菜光、温敏雄性不育类型划分及育种应用提供了依据。

A photoperiod/thermo-sensitive male sterile line, named Huiyou50S, was developed from a spontaneous semi-sterile plant found in Brassica napus cultivar Huiyou50. The male sterility of Huiyou50S was controlled by recessive nuclear genes. Huiyou50S presents male sterile under high temperature and long photoperiod condition, and fertility under low temperature and short photoperiod. The cytological characters of pollen and the anther development of Huiyou50S at the different stages were compared with its near isogenic line Huiyou50F, which is the male fertile sibling, by techniques including semi-thin sections, scan electronic microscopy, pollen grains staining with aceto-carmine, and whole anther clearing with methyl salicylate. The result indicated that the anther development of Huiyou50S was similar to that of Huiyou50F from sporogenous cell, pollen mother cell, meiosis, to tetrad stage. At the uni-nucleate stage, although the exine formed, the protoplast of microspores condensed, and the cell became empty. At last all cellular content of pollen degraded completely and only the empty and distorted shell remained. The tapetum development of Huiyou50S was similar to that of Huiyou50F up to tetrad stage, but its tapetal cells rapidly disintegrated at the uni-nucleate stage, which occurred earlier than that in Huiyou50F, while the tapetum of Huiyou50F did not degenerate at this stage. In conclusion, the microspores of Huiyou50S abort mainly at the uni-nucleate stage, and there are some associations between pollen abortion and tapetal cells’ disintegration. This result is helpful to classification and utility of photoperiod/thermo- sensitive genic male sterility. 更多