Cytological evaluation of annual species of the Onobrychis genus in Iran

The genus Onobrychis is an important forage crop consisting of approximately 130 annual and perennial species. In this study, 13 populations of five Onobrychis species were analyzed. The basic chromosome number varied from x=7 to x=8. According to Stebbins’ classification, populations such as O. aucheri subsp. psammophila, O. crista-galli (1) and O. crista-galli (2) were classified in symmetric class B, while the others were classified in A. Based on interchromosomal symmetry, O. aucheri subsp. tehranica and O. crista-galli (1) had the most asymmetrical and evolutionary karyotype, and O. crista-galli (6) had the most symmetrical karyotype. Based on intrachromosomal symmetry, O. crista-galli (6) had the most asymmetrical karyotype. Populations were divided into three classes by cutting dendrogram resulting from cluster analysis (Ward) using six parameters (SA, LA, TL, AR, r-value, CI). The greatest distance observed was between O. crista-galli (3) and O. crista-galli (5), while the smallest distance was between O. crista-galli (2) and O. crista-galli (6). Populations were separated into three classes using two indices (A1 and A2). The greatest distance observed was between O. crista-galli (6) and O. aucheri subsp. tehranica, while the smallest distance was between O. crista-galli (5) and O. crista-galli (3).