Karyological and flow cytometric studies of Tulipa (Liliaceae) species from Iran

Chromosomal and karyotype parameters and genome size were examined in 22 Iranian populations of nine different Tulipa species, using squash technique and 1 % (w/v) aceto-orcein stain. Flow cytometric studies were performed using PI staining method and Vicia faba cv. Inovec (2C DNA = 26.9 pg) as a reference standard. Most species were diploid (2n = 2x = 24), having three chromosome types (“m”, “sm”, “st”). The chromosome length (TL) varied from 6.4 μm (S2) to 12.90 μm (S3). Total chromosome volume (TCV) ranged from 32.9 μm3 (S2) to 66.0 μm3 (S8). Statistical analyses confirmed more intraspecific chromosomal and genome size variations than interspecific. S1E2, S2E1 and S5E2, with the highest intrachromosomal (MCA) and relatively high interchromosomal asymmetry (CVCL), indicated higher asymmetry in the karyotype. The genome size in Tulipa species of Iran is being reported for the fist time. The mean 2C DNA was 54.52 pg, and ranged from 77.40 in S6E2 to 31.51 pg in S9E2. Significant positive correlations were found between 2C DNA and either TL or TCV.