In the present paper, three Coptis species, collected from Sichuan and Chongqing, China, were used for karyotypic analyses. The results indicated that both C. chinensis and C. omeinensis were diploid with chromosome 2n = 2x = 18, and C. deltoidea was an autotriploid with chromosomes 2n = 3x = 27, which explained why this species was morphologically so isolated from other species and its sterile and narrow distributing regions. The relationship between C. chinensis and C. omeinensis based on chromosome data was discussed. The probable origin of C. deltoidea was also suggested.
China ; Chromosomes, Plant ; genetics ; Coptis ; genetics ; Diploidy ; Karyotyping