Karyological studies and chromosome variation among Iranian endemic Allium species (Amaryllidaceae)

One of the largest monocotyledonous genus in the Amaryllidaceae family is the Allium genus that includes approximately 900 species. This study aimed to examine the variations and clustering of eight Iranian endemic Allium species based on karyotype features. The species were collected from wild habitats across different geographical areas of Iran. A. sativum, A. stipitatum, A. fistolosum, A. umbellicatum, A. stamineum, A. lenkoranicum, and A. rubellum, were diploids (2n = 2x = 16), but A. atroviolaceum was triploid (2n = 3x = 24). The results represent x = 8 for basic chromosome numbers in all species. Analysis of variance showed significant interspecific variations for all eight chromosomal parameters tested. The mean of chromosome lengths was 11.19 μm, varied from 8.59 μm to 13.81 μm for A. atroviolaceum and A. stipitatum, respectively. In all species, the chromosome types were determined as mostly metacentric (m) and submetacentric (sm), formed five different karyotype formulas of 16m (A. stipitatum, A. fistolosum, A. stamineum), 14m+2sm (A. sativum, A. rubellum), 12m+4sm (A. lenkoranicum), 10m+6sm (A. umbellicatum), and 24m (A. atroviolaceum). According to Stebbins' classification, all karyotypes were grouped in the 1A class and represented the most symmetrical karyotypes. The information obtained from karyotype and chromosome morphology has an appreciable value in understanding the taxon evolution and interrelations.