---

作 者 ：皮军  周颂东  何兴金  唐自慧  王强

期 刊 ：西北植物学报 2008年 2期

关键词：大戟科；野桐属；染色体数目；核型；进化；

Keywords:Euphorbiaceae, Mallotus, chromosome numbers, karyotype, evolution,

摘 要 ：采用常规压片法对大戟科野桐属4种(含变种)6个居群进行了体细胞染色体数目和核型研究。研究结果显示其染色体数目为2n=22或2n=44,核型均为1A。核型公式分别为:绒毛野桐2n=4x=44m;白背叶2n=20m 2sm或2n=2x=22m或2n=20m(2sat) 2sm;广西白背叶2n=2x=22m;毛桐2n=2x=22m。其中白背叶[Mallotus apelta(Lour.)Muell.-Arg.]、广西白背叶[M.apelta(Lour.)Muell.-Arg.var.kwangsiensisMetic.]和毛桐[M.barbatus(Wall.)Muell.-Arg.]的染色体数目和核型均为首次报道。根据野桐属细胞分类学资料推测,多倍化和异基数变异是野桐属属内物种形成的重要方式。

Abstract:The somatic chromosome numbers and karyotypes of 4 species embracing 6 populations from China were investigated by conventional pressed disc method.The results indicated that the chromosome numbers of these species were 2n=22 or 2n=44 and karyotypes of al

---