老芒麦(Elymus sibiricus L.)种子发育过程的形态解剖学特征

应用解剖学及组织化学方法对老芒麦种子发育过程进行了观察研究。结果显示，其种子发育过程的形态变化具有禾本科植物的典型特征：胚胎发育为禾本型，胚乳为核型胚乳，其最外一层细胞发育为糊粉层，籽实皮由内珠被及子房内表皮发育而成；但有其特性：合子未显示出极性，中贮藏有丰富的淀粉粒。第1次分裂为横分裂，偶有斜向分裂，之后顶细胞纵分裂，基细胞横分裂；宿存助细胞可保留到椭圆形原胚时期，与丝状器都有PAS正反应．显示了宿存助细胞及丝状器与营养物质的转运有关；少数种子有胚发育迟缓的现象；不同种子发育的早期原胚之间存在淀粉粒含量的差异；约有1％的成熟种子中缺胚或胚极小。

Observations on seed development of Elymus sibiricus L.

The seed development of the Elymus sibiricus L. was of character in typical graminaceous plants. The embryogeny developed to Gramineous type. Endosperm was of nuclear type.Its outer layer cells developed to aleurone layer. Seed coat was developed from both inner integument and the inner epidermis of ovary. However, it had its own characters. The zygote was round-shaped, appeared no polarity and filled with starch grains. The first division was transverse, occasionally oblique, and then produced apical and basal cells. The vertical division of the apical and the transverse division of the basal formed 4-cells proembryo. The persistent synergid existed during ellipsoidal embryo formation, and had a strong PAS reaction which was similar as filiform apparatus. The embryo development was found retarded in some seeds. The number of starch grain was different among the early proembryos. About 1% of the matured seeds did not contain embryos.