非洲狼尾草无融合生殖胚囊显微结构特点

对非洲狼尾草（pennisetum squamulatum Freson)无融合生殖胚囊做了显微结构观察，一个珠心中常有几个无融合生殖胚囊，卵细胞高度液泡化，含大量小液泡，细胞呈现极性，但多数情况下细胞核位于中心位置，很少显示不均匀分布，中央细胞的极核总量与卵细胞相连接，珠孔区域有伸长的珠心细胞。

MicrostructuralAspects of Mature Embryo Sac Derived from Nucellus Cells in Pennisetum Squamulatum

Microstructural study was made to characterize mature apomictic embryo sac in pennisetum squamulatum Freson. Often several apomeiotic embryo sacs occur in a single nucellus. The egg cell in the mature embryo sac derived from the ordinary nucellar cell is highly vacuolized and contains numerous small vacuoles. Most aomeiotic egg cells reveal morphological polarity,but their nucleus does not always show uneven distribution,mostly located centrally. The polar nucleus in central cell was found almost always in connection with the apomeiotic cell. The synergid becomes degenerated soon after the inflorescence opens. There are several nucellar cells in micropylar region that develop into embellum.