重楼属和延龄草核型的一致性

KARYOTYPE UNIFORMITY OF PARIS AND TRILLIUM TSCHONOSKII

本文报道的重楼属3个种和变种与延龄草的核型基本一致,表明它们之间的亲缘关系很近,其核型简式为:延龄草(T. tschonoskii)2n=10=4m+2m(SAT)+2st(SAT)+2t(SAT)+1B;五指莲(Paris axialis)2n=10=6m+2t+2t(SAT)+2B;狭叶重楼(P. polyphylla var. stenophylla)2n=10=2m(SAT)+4m+2st+2t;小重楼(P.polyphylla var.minora)2n=10=4m+2sm+4t.

This paper reports karyotypes of one species and two varieties of the genus Paris and Trillium tschonoskii from Mount Emei of Sichuan. The karyotypes of four species, Paris axialis H. Li, Paris polyphylla Smith var. steno-phylla Franch., Paris polyphylla Smith var. minora S. F. Wang and Trillium tschonoskii Maxim are basically uniform and show that there is an affinity between Paris and Trillium. The karyotypes of them can be expressed by the following formulae. T. tschonoskii 2n = 2x = 10 = 4m + 2m (SAT) +2st(SAT) +2t(SAT) + lB, P. axialia 2n = 2x = 10 = 6m + 2t + 2t (SAT) +2B; P. polyphylla var. stenophylla 2n = 2x = 10 = 2m ( SAT ) +4m + 2st + 2t; P. polyphylla var. minora 2n = 2x = 10=4m+2sm+4t. From above karyotype analysis, it is shown that there is an affinity between Paris and Trillium. We can imagine that they had evolved from the same ancient ancestor. But there are some differences in the size, number and presence or absence of the satellites and B-chromosomes. The presence or absence of the B-chromosomes is closely related to the different ecological enviroments.