Chromosome number reports in five Onobrychis species (O. sect. Onobrychis, Fabaceae) in Iran

In this study the original mitotic chromosome counts are presented for 5 Onobrychis species of O. sect. Onobrychis in Iran, 2n = 2x = 14 for O. persica, 2n = 4x = 28 for O. viciifolia, 2n = 4x = 28 for O. altissima, 2n = 2x = 14 for O. shahpurensis and 2n = 2x = 14 for O. sosnovskyi. The basic chromosome numbers of all studied taxa are consistent with the proposed base number of x = 7. In addition, the meiotic chromosome number of 2n = 4x = 28 for O. viciifolia and O. altissima and of 2n = 2x = 14 for O. sosnovskyi and O. persica are reported here. This study is the first report on the chromosome counts of O. persica and O. shahpurensis. All studied taxa displayed regular bivalent pairing and chromosome segregation at meiosis. However, some abnormalities were observed in the taxa are discussed.