In the present study,floral organogenesis of Saururus chinensis was observed and compared with that of 5. cernuus. The two species share essentially similar patterns of floral initiation and stamen development. Their inflorescence produces 'common primordia' in acropetal succession on the flanks of the inflorescence meristem. Each primordium bifurcates transversely to form a floral apex above and a bract primordium below. Six stamens arise in three pairs at the floral apex. The median sagittal pair arises first, the lateral distal pair second, and the lateral proximal pair arises last. On the contrary,the initiation of carpels is quite different from each other. In 5. cernuus, the median sagittal pair arises first, and the lateral pair next. In S. chinensis, however, the lateral pair arises first, and the median sagittal pair second. The present study also made a brief generalization using the data obtained from different fields on the relationship of the two species in the genus Saururus, which are
首次报道了毛果猴子木 ( Cam ellia yunnanensis( Pitard ex Diels) Cohen Stuart var. camellioides( H u)Ming)雌雄配子体的形成和发育过程 ,并对业已报道的 8种山茶属植物的主要胚胎学特征进行了比较。结果显示 ,胚胎学性状在山茶属内具有较大的相似性 ,腺质绒毡层、同时型小孢子母细胞减数分裂、二细胞成熟花粉、倒生胚珠、双珠被、薄珠心、单孢原、合点端功能大孢子、葱型胚囊发育等特征为各代表种共有 ,主要的不同在于珠被绒毡层的有无、卵器和反足细胞的分化情况。笔者初步推测了这些差异在系统演化上的意义。
The embryogenesis, pollen germination, floral character and seed physiology of the endangered plant Manglietia aromatica Dandy were investigated. Based on this study, this species has very low seed set rate. The abortion rate of functional megaspores in all the ovules is 27.9%, the egg cell abortion rate of mature embryo sacs is up to 80%, and the germination rate of pollen grains is as low as nearly 0.01%. In addition, the floral structure appears to be another limited factor for the effective pollination of this species. The endangerment mechanism of this species seems to be comprehensive. Human's destroying actions are the direct factors that have made the population degenerate quickly; low reproductive ability and the destroyed environments are the main reasons that prevent the population from renovating and spreading. Therefore, the conservation measures suggested by this study are to research the breed technology, artificial population renovating, in situ conservation, and ex situ conservation.
