Abstract:

This paper has dealt with the chromosome numbers and karyotypes of 4 species of the genus tupistra. It is found that all the species studied are diploids with chromosome num-ber 2n=38. The karyotype formula of T.annulata is 2n=2x= 38=34m(2SAT) +4sm,T. fimbriata2n=2x=38=30m+8sm,T.annulata 2n=2x=38=24m (6SAT) + 14sm andT.grandistigma 2n= 2x= 38= 20m+6sm+12st (2SAT) . The karyotypes of T.ensifolia, T. fimbriata, T. annulata are unimodal while the Karyotype of T. grandistigma is bimodal. T.grandistigma is a advanced species in the genus Tupistra.

Key words: Tupistra, Karyotype, Chromosome

摘要：

本文报道了开口箭属（Tupistra）4个种的核型，4个种皆为2倍体，染色体数目为2n=38，基数为X=19，核型有2种类型：剑叶开口箭（T.ensifolia: 2n=2X=38=34m（2SAT）＋4sm）、齿瓣开口箭（T.fimbiata: 2n=2x=38=30m＋8sm） 和环花开口箭（T.annulata：2n=2x=38=24m（6SAT）＋14sm）的核型为2B型，由一型染色体组成，长柱开口箭（T.grandistigma：2n=2x=38=20m＋6sm＋12St（2SAT））的核型为2C型，由二型染色体组成。长柱开口箭是属内较为进化的一个类群。

关键词: 开口箭属;核型, 染色体