【摘要】 以30年生白桦(Betulaplatyphylla)的雌花序为材料,研究了白桦有性生殖期间胚珠和胚乳的发育过程,以及胚和胚乳发育之间的关系。观察结果表明:白桦为合生心皮雌蕊,花柱2,子房室2,每室1～2个胚珠或无,中轴胎座,倒生胚珠,单层珠被,厚珠心发育;胚柄短小,由三个细胞构成;在历时4个月之久的雌配子体形成、胚胎发育直至成熟期间,胚珠经历了形态结构的变化和适应;在胚的发育过程中,胚乳起主要营养作用,胚乳发育类型为核型胚乳。最后对胚、胚乳发育的解剖结构及其相互关系以及影响种子质量的各环节进行了研究和讨论。更多还原

【Abstract】 The development processes of ovule and endosperm, and the relation of embryo and endosperm developments in sexual reproduction for the female inflorescence of thirty-year-old Betula platyphylla were studied. The results showed that the flower of B. platyphylla is syncarpous gynoecium, with 2 styles. The ovary has 2 locules, with 1, 2 ovules or absence of each locule, which is axile placenta, anatropous, unintegmic, and crassinucellate. Suspensor is shorter and consists of 3 cells. From macrogamephyte formation, and embryonal development to the autumn in four months, the ovule undergoes the change of morphological structure and adaptation. At the same time, endosperm plays a main advancing role in the embryonal development, which is nuclear type. And then, the anatomical structures of embryo and endosperm developments, their interrelation, and the each factor of influencing the quality of seed were studied and discussed.更多还原