Karyomorphology of some taxa of Paris (Melanthiaceae) from Si-chuan province, China

摘要

The karyomorphology of nine taxa of Paris from Sichuan province in China were reported. The primary lesions of P. undulatis were newly observed, the chromosome number and karyotype were reported for the first time. All of the materials were diploids. The chromosome numbers of all taxa studied were 2n =2x =10. The karyotypic asymmetry types of all taxa studied were 2A, except for P. polyphylla var. chinensis was 2B. Satellites were observed in four taxa, P. undulatis, P. polyphylla var. polyphylla, P. fargesii var. brevipetalata and P. polyphylla var. polyphylla. All of the investigated taxa were absent B chromosome except for P. polyphylla var. polyphylla and P. axialis. Karyotypic formula of nine Paris taxa were as follows: P. undulatis, 2n = 6m +4t (2sat); P. polyphylla var. chinensis, 2n =6m +4t (2sat); P. polyphylla var. yunnanensis, 2n= 6m + 4t; P. cronquistii, 2n= 6m + 4t; P. polyphylla var. polyphylla, 2n= 6m +2st (2sat)+2t (2sat)+2bs; P. axialis, 2n= 6m +4t +2bs; P. fargesii var. brevipetalata, 2n = 6m +4t (2sat); P. mairei, 2n = 6m +4t; P. marmorata, 2n =6m + 1st +3t. The vari-ability of karyotypes occurred among taxa and phylogenetic positions of some taxa were investigated, and the infrageneric and the intergeneric relationships of Paris were discussed.