Karyotype studies on ten iris species (iridaceae) from sichuan, china

Abstract

Chromosome number and karyotype analysis of 10 taxa in the genus Iris (Iridaceae) from Sichuan, China were investigated in this study. The chromosome number and karyotype formula of 10 Iris taxa are as follows: I. lactea, 2n = 40 = 28m + 10sm + 2st; I. lacteavar.chinensis, 2n = 40 = 18m + 16sm + 6st (6SAT); I. chrysographes, 2n = 40 = 18m + 22sm (2SAT); I. japonica, 2n = 36 = 16m + 14sm + 6st; I. tectorum, 2n = 28 = 16m (4SAT) + 12sm (2SAT); I. confusa, 2n = 32 = 8m + 18sm + 6st; I. germanica, 2n = 40 = 16m + 20sm + 4st; I. sichuanensis, 2n = 26 = 12m (4SAT) + 12sm (2SAT) + 2st; I. leptophylla, 2n = 26 = 14m (2SAT) + 10sm (4SAT) + 2st; I. goniocarpa, 2n = 26 = 12m + 12sm + 2st (2SAT). The karyotypes of I. sichuanensis, I. leptophylla, I. goniocarpa, I. lactea, I. confusa and I. germanica were firstly reported, and the chromosome number of I. confusa and I. germanica were newly observed. Based on the karyotype results and previous studies, we suggested that: (1)I. wattii, I. confusa and I. japonica are three independent species; (2) I. sichuanensis, I. leptophylla and I. goniocarpa are three independent species with close relationships; (3) it is reasonable to treat I. lactea var.chinensis as a variety of I. lactea. © 2009 Taylor & Francis Group, LLC.