Fatemeh Hajmoradi - Department of Biology, Payame-Noor University, Tehran, Iran
Massoud Ranjbar - Department of Biology, Herbarium division, Bu-Ali Sina University, Hamedan, Iran

In this study the original mitotic chromosome counts are presented for Onobrychis subnitens sect. Hymenobrychis in Iran. In this regards flower buds were fixed in modified Carnoy’s solution for 24 h at room temperature and then stored in 70% ethyl alcohol at 4°C until used. Anthers were squashed and stained. The basic chromosome numbers of studied taxon is x = 8 that is inconsistent with the proposedbase number of x = 7. The ancestral chromosome number in the genus is x = 8 and that species with x = 7 are derived through aneuploid loss. Although this taxon displayed regular bivalent pairing and chromosome segregation at meiosis, some meiotic abnormalities were observed. The meiotic abnormalities included cytomixis, varied degrees of chromosome stickiness, fragmented chromosomes, occurrence of laggard chromosomes, chromosome bridges, desynapsis, micronucleus and tripolar cells.

chromosome number, meiotic behaviour, Onobrychis subnitens, O. sect.Hymenobrychis