黄精属的细胞分类学研究Ⅰ.8个种的核型和进化

作者研究了中国产黄精属8个种的核型,结果如下:热河黄精,2n=22=14m(4SAT)+2sm(SAT)+6st;多花黄精,2n=22=8m+8sm(2sc)+6st(2sc);玉竹,2n=20=12m+8sm;小玉竹,2n=20=8m(2sc)+8sm+4st;长梗黄精,2n=16(18)=10m+4sm+2st;二苞黄精,2n=18=8m+10sm;黄精,2n=24=4m+8sm(2sc)+12st(2sc);卷叶黄精,2n=20=12m(2sc)+8sm。作者推测该属的染色体基数x=10。染色体数目进化的趋势是:非整倍性变异为主,整倍性变异为次;上升性变异为主,下降性变异为次。按照核型不对称程度,8个种的核型可分为三个等级。核型由对称向不对称进化是与染色体数目的进化趋势大体上相关的。

STUDIES ON THE CYTOTAXONOMY OF POLYGONATUM Ⅰ.Karyotypes and evolution of eight species of Polygonatum in China

The present paper analyzed the karyotypes of 8 species of iPolygonatum in China. The results are as follows: P. macropodium Turcz. 2n=22=14m(4SAT)+2sm(SAT)+6st; P. cyrtonema Hua 2n=22=8m+8sm(2sc)+6st(2sc) ; P. odoratum(Mill.)Druce 2n=20=12m+8sm; P. humile Fisch. ex Maxim. 2n=20=8m(2sc)+8sm+4st; P. filipes Merr. 2n=16(18)=10m+4sm+2st; P. involucratum Maxim. 2n=18=8m+10sm; P. sibiricum Delar. ex Redoute 2n = 24 = 4m + 8sm (2sc) + 12st (2sc);P. cirrhifolium Royle 2n = 20 = 12m (2sc) + 8sm.From this paper and previous reports by other authors, it is presumed that the basic chromosome number of Polygonatum is X=10. In the trend of evolution of the chromosome number, as a rule, aneuploid variations are more predominant than the euploid variations, ascending variations is the main stream and descending variation is not so important. According to degree of asymmetry of the karyotypes, the 8 species might be divided into three gradations. The evolution of karyotype variation from symmetry to asymmetry is correlated with the trend of evolution of the chromosome number.