丰都车前的细胞学研究,兼论它的多倍体起源

对长江三峡库区特有濒危植物丰都车前(Plantago erosa var.fengdouensis)进行了细胞学研究,包括有丝分裂和减数分裂两方面.丰都车前可能为一异源四倍体。其核型公式为2n=4x=24=12m(2sat)+12sm(2sat),属于2A型.极端的环境压力尤其是季节性的水淹可能是此四倍体物种形成的主要原因。对同属内的另一物种车前(P.asiatica)进行了比较观察,确证车前为六倍体。该实验为丰都车前的保育遗传学研究提供了细胞学证据。

Cytological studies of Plantago erosa var.fengdouensis,with special reference to its polyploid origin

Cytological studies including mitosis and meiosis of Plantago erosa var. fengdouensis,an endangered plant native to the Three-Gorge Reservoir Area of China,have been investigated. It may be an allotetraploid. The karyotype can be formulated as 2n=4x= 24= 12m(2sat) + 12sm(2sat) .belonging to 2A type. Extreme environmental impetus especially the seasonal flooding may play a principal role in the polyploid formation of it. Chromosome number of P. asiatica is reconfirmed, and P. asiatica is a hexaploid. This study will supply a cytological evidence for the further genetics conservation research of Plantago erosa var. fengdouensis.