路南海菜花的核型分析及其海菜花属的演化探讨

Caryotype of Ottelia acuminata var. lunanensis H. Li and evolution of Ottelia Pers

海菜花属(Ottelia Pers.)为沉水单子叶植物,只生长于淡水生境中,具有重要的生态价值、环境指示作用以及植物系统学研究意义.本文首次报道了特产于我国云南石林湖泊中的路南海菜花(Ottelia acuminata var.lunanensis H.Li)的体细胞染色体数目为22条,核型属"1B"型,核型公式2n=2x=22=18m+4sm.结合已研究的花部特征和核型资料讨论海菜花属种间的亲缘关系及演化,为海菜花(Ottelia)的利用和保护提供细胞生物学证据.

Ottelia is a kind of submerged monocots inhabiting only in fresh water.This genus has an important ecological value and much significance of environment-monitoring,as well as the material of a plant systematic study.The auhtors presented for the first time that Ottelia acuminata var.lunanensis H.Li,a peculiar plant growing in the lakes of Stone Forest County of Yunnan Province,China,has 22 somatic chromosomes,which are classified as ＂1B＂ caryotype （2n=2x=22=18m＋4sm）.By analyzing both the flower characteristics and the caryotypes of Ottelia,the consanguineous relationships among its varieties and their evolution were also discussed,which proposed a cell-biological theory for the using and protection of Ottelia.