A karyotypic study was performed on 15 populations of Eremostachys laciniata Bunge from Iran to qualify cytological variation for use in breeding programmes. Ten mitotic root tip cells at the metaphase stage were prepared from each population by the squash method. The chromosomes of suitable mitotic cells were counted and various parameters including long and short arm, chromosome lengths, total length of the haploid chromosome complement, arm ratios, and the centromeric index were measured. All 15 populations were diploid with 2n = 2x = 22 and were differentiated by their karyotype and parameters. The E. laciniata populations occupied class 1A of Stebbins’ karyotype classification, indicating the presence of a primitive symmetrical karyotype in these 15 populations. The size of the mitotic chromosomes was medium and mean chromosome length ranged from 3.84 - 4.77 μm. The shortest chromosomes were observed in the Ajabshir population and the longest in the Heydarabad population. The Heydarabad population also had the largest total chromosome length and the Ajabshir population had the smallest total length. The centromeric indices of the chromosome complements varied from 39.3 - 43.7%. In all populations, metacentric chromosomes were the most common, whereas sub-metacentric chromosomes were rare. The A1 index varied from 0.215 (Areshtanab) to 0.337 (Til), the A2 index ranged between 0.116 (Til) and 0.143 (Kaleybar) and the AI index ranged from 0.051 - 0.097. The results of principal component analysis showed that the main elements of the first three main components determined 97% of the total variance. Cluster analysis by Ward’s method indicated that all 15 populations could be classified into three groups.

Keywords