Karyotypic Study of Sect. Hymenobrychis of Onobrychis in Iran

Nine populations of sect. Hymenobrychis of sainfoin were collected from natural habitats across Iran. Number and size of chromosomes as well as karyotypic formula of the populations were assessed using their root tip meristemes. The basic chromosome number varied between x=7 and x=8 and their chromosomal type was metacentric and sub-metacentric. The highest genomes length belonged to O. chorassanica (22.144µm) and the lowest to O. amoana subsp. meshhedensis (14.409µm). The results of analysis of variance based on unbalanced completely randomized design showed significant differences among the populations for the most of the studied traits (P<%1). O. michauxii 2 was classified as asymmetric class of B and others as A. O. amoena subsp. meshhedensis with 14m formula, stand in A class with had the most relative length of shortest chromosome (68.26), lowest intra chromosal asymmetrical (0.12) lowest differences of relative length(5.31) and the high total form percentage was the most symmetrical species. Using principal components analysis, the first three components justified %95.4 of total variance. By cutting dendrogram, resulted from cluster analysis based on the karyptipic parameters species, the highest distance obtained between O. mazanderanica and O. michauxii and the lowest metric distance value obtained between populations of O. mazanderanica.