Karyological Study on Some of Species of Trifolium genus in IRAN

The genus Trifolium L. (Fabaceae) an important member of forage plants comprises approximately 248 species. The germplasm used in this study containing 19 genotypes from 10 species of clover genus considered by Karyotypic studies. In this study, the Video Analysis System was used for karyotype analysis. The basic chromosome number was varied between X=5 (in two diploid genotypes), X=7 (in three diploid genotypes) and X=8 (in twelve diploid genotypes and two tetraploid genotypes). The genotypes number 7585, 27 and 5156 classified to symmetric class of 2A and others stand to 1A. The plot of genotypes, based on two parameters of A1 and A2, and symmetry types of Stebbins had the same results. The Results of analysis of variance based on completely randomized design(CRD) showed a significant differences among the genotypes for all traits (P<%1). Using principal component analysis, the first, second and the third component justify %92.15 of total variance. In the first component, the length of the long arm, long arm relative percentage, short arm, short arm relative percentage and the total length of chromosome which had the highest coefficients of eigen values also had the most significant role in total variance. In the second component the feature of the arm ratio, centromer index and total form percentage had the most important part in creating of total variance. By cutting dendrogram resulted from cluster analysis (UPGMA) based on 9 parameters (TL, LA, %LA, SA, %SA, AR, CI, DRL, %TF) in genetic distance 3.89, the genotypes classified to three classes which certainly the first and the second components had the most significant role in separated classes. In this study there was the highest distance between T.hybridum (27) and T.hirtum(3704) which imply the least affinity between them. There was the least karyotypic difference between two genotypes 314 & 2139 from the species of T.fragiferum. The diagram of the genotypes dispersion, based on two main components, classified the genotypes in three separated groups, supporting the results of cluster analysis. By cutting dendrogram produced from cluster analysis (UPGMA) based on 2 parameters (A1 and A2) in genetic distance 1.75, the genotypes classified to three classes.In this study there was the highest distance between T.hybridum(27) and T.alexandrinum (8313) which imply the least affinity between them. There was the least karyotypic difference between two genotypes T.repens (Alice) and T. subterraneum(7593).