深山含笑大、小孢子发生和雌、雄配子体发育研究

Mega-and Microsporogenesis and Development of Female and Male Gametophytes in Michelia maudiae Dunn

采用石蜡切片技术对深山含笑大、小孢子的发生和雌、雄配子体发育进行观察:深山含笑花药4室,花药囊壁由5-7层细胞构成,腺质绒毡层,小孢子胞质分裂为修饰性同时型,四分体有四面体型、对称型,偶有交叉型,成熟花粉为2细胞型;胚珠倒生、双珠被、厚珠心,大孢子四分体直线型排列,合点端为功能大孢子、雌配子体发育方式为蓼型。从雌、雄配子体发育时间的先后来看,深山含笑春季雌、雄配子体能正常发育,雄蕊先熟,雄蕊和花瓣凋谢后雌蕊大孢子母细胞才形成。而秋季开花的深山含笑,花药中小孢子在孢原细胞或初生造孢细胞期停止发育,花粉败育;雌蕊胚珠珠心组织也未见大孢子母细胞发育,开花后雌蕊随花柄凋落。该研究为深山含笑生殖发育和杂交育种积累了资料。

The mega- and microsporogenesis and development of female and male gametophytes in Michelia raaudiae Dunn were investigated by using the paraffin section method. Anthers are tetradymous and the anther wall is eomposed of 5 -7 layer of cells, Glandular tapetum, Cytokinesis in meiosis is modified simultaneous type, the tetrads are tetrahedral, isobilateral and deeusate. Mature pollen grains are 2-cell type. The ovule of M. maudiae is anatropous bitegmic and nucellus thickly. The megaspore mother cells undergo meiosis divides into linear type tetrads, and the one in the chalazal end is functional, Polygonum type. The female and male gametophytes in spring-flowering M. maudiae were developed normally, heterogamy. The megaspore mothercells formed after the petals and stamen were withered. The development of microspore in autumn is in the period of sporozoic eell or primary spore, abortionthen. Megaspore in autumn-flowering M. maudiae undeveloped when flowering, withers away after flowering, were mostly developed unnormally. The study had aecumulated information on the reproduction and hybridization in M. maudiae Dunn.