白菜核雄性不育系可育和不育花药中Ca^(2+)的分布

Calcium Distribution in Fertile and Sterile Anthers of a Genic Male Sterile Chinese Cabbage

研究了白菜(Brassica campestris L. ssp. chinensisMakino)细胞核雄性不育系花药中 Ca2+的分布特征。在可育花药发育过程中,减数分裂后花药壁细胞中钙颗粒明显增加。早期小孢子开始积累钙颗粒并特异性地附在小液泡膜上。小孢子分裂后,大液泡消失过程中又伴随着许多钙颗粒附在小液泡膜上,显示出Ca2+与花粉中液泡的形成和分解有关。在不育花药中,最早出现的钙颗粒异常分布是在小孢子母细胞的胼胝质壁中积累了较多的钙颗粒。然而,在小孢子细胞质中钙颗粒一直很少,也不形成大液泡,最后通过细胞质收缩的方式败育。这是首次发现Ca2+参与调控花药发育过程,其异常分布与花粉败育密切相关。

Potassium antimonite was used to locate calcium in the fertile and sterile anthers of a genic male sterile Chinese cabbage （Brassica campestris L. ssp. chinensis Makino） to probe the relation between Ca^2＋ and fertility and sterility of anthers of the cabbage. During fertile anther development, calcium granules increase in number in anther wall cells after meiosis, and then appeared also in locule, suggesting a calcium influx into locule from anther wall cells （Plate Ⅰ-4）. Then the number of calcium granules in microspore cytoplasm also increased at early stage （Plate Ⅱ-1）, accumulated mainly on the membrane of small vacuoles which were fusing to form big ones to make a polarity in the cell and to prepare asymmetric division of microspore （Plate Ⅱ-3, 4）. After microspore division and the big vacuole decomposition, many calcium granules accumulated again on the membrane of the vacuoles （Plate Ⅲ- 1, 2）, displaying calcium regulates vacuole formation and decomposition during pollen development. In sterile anthers, abnormal distribution of calcium granules first appeared in callus wall of microspore mother cell （Plate Ⅳ-1）. However, only a few calcium granules appeared in early microspores, which then could not form small vacuoles and finally a big vacuole （Plate Ⅳ-2, 3）. The aborting microspores degenerate by cytoplasm shrinking （Plate Ⅳ-5, 6）. The difference pattern of distribution of calcium granules between the fertile and sterile anthers indicates that anomalies in the distribution of calcium accumulation are correlated with the failure of pollen development and pollen abortion.