Karyomorphological Analysis on Several Diploid Populations of Achillea biebersteinii Afan. (Asteraceae) from Iran

Comparative karyotype analysis of related species and populations has been used to describe patterns of chromosomal evolution within a group. In order to investigate cytogenetic variation in Achillea biebresteinii , root meristem zone of nine populations were removed and prepared using squash method. Image analysis system and Micro-measure software were implanted to karyotype providing cytogenetic parameter measurements. Although all the populations have the diploid chromosome number (2n = 18) and the haploid number (x = 9), but they could be differentiated by their karyotype formula and quantitative parameters of the karyotypes. Phenetic distance and principal component analysis showed that they could be classified in four clusters (groups). The mean chromosome length ranged from 3.82 (±0.48) to 7.77 (±0.12) µm. The chromosome types were detected as mostly metacentric (m) and submetacentric (sm), showing the karyotype formula of 18m (two populations), 16m + 2sm (five populations), 14m + 4sm (one population) and 2M + 14m + 2sm (one population). The karyotypes of the populations are almost similar. According to Stebbins’, the populations are classified to symmetric classes of 1A and 2A.