Abstract: Abstract The karyotypes of five species of Paris, i. e, P. cronquistii (K2n=2x= 10+2bs=6m+4t+2bs), P. vietnamens is ( K2n = 2x = 10 = 6m + lst+ 30 P. delavayi (K2n = 2x = 10 + ibs = 6m+4t+ibs) , P. forrestii ( K2n=2x= 10+2bs=6m+4t+2bs) , P. vaniotii (K2n = 2x = 10 = 6m+4t)were analysed based on cells at mitotic metaphase. Origin of the materials used in this work are pro-vided in Table 2 f the micrographs of mitotic metaphase of 5 species are provided in Fig. If the idiograms in Fig. 2 and the parameters of chromosomes are provided in Table 1. All the karyotypes in this paper are reported for the first time.

Key words: Paris

摘要： 本文报道5种重楼植物的核型：凌云重楼（P. cronquistii)；南重楼（P. vietnamen-sis) ，金线重楼（P. delavayi); 长柱重楼（P.forrestii);和平伐重楼(P.vaniotii)。讨论了重楼属植物的核型结构和倍性的变异，以及杂合性、多态性、B染色体等染色体的结构变异。并将重楼属植物的核型归纳成三个主要的基本类型。1．4t型，基本核型为2n＝2x＝10＝6m＋4t，分布于南部热带亚热带的多叶重楼P.polyphylla等13种的核型属于这一类型;2.2st型，基本核型为2n＝2x=10＝6m＋2st＋2t，分布于北温带的P.verticilata等 5种属于这一类型；3.4st型，核型为2n=2x=1＝=6m+4st, 仅有巴山重楼P. bashanesis的核型属这一类型。每个类型中各个种之间在染色体的结构上又表现出一定的差异。根据植物的染色体核型的演化规律，对三个类型核型的演变作了探讨。

关键词: 重楼属, 细胞分类, 核型, 倍性, 杂合性, 多态性, B染色体