【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。更多还原

【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 all were 1A.The karyotype formulae of Mallotus apelta(Lour.) Muell.-Arg.var.kwangsiensis Metic.and M.barbatus(Wall.) Muell.-Arg.were 2n=2x=22m,whereas those of M.apelta(Lour.) Muell.-Arg.and M.japonicus var.oreophicus Muell.-Arg.S.M.Hwang were 2n=20m+2sm or 2n=2x=22m or 2n=20m(2SAT)+2sm and 2n=4x=44m,respectively.Chromosome counts and karyotypes of M.apelta,M.apelta var.kwangsiensis,M.barbatus were documented for the first time.It was concluded that polyploidy and dysploidy were effective in speciation.更多还原