KARYOTYPIC STUDY OF TRIFOLIUM SPECIES AND CULTIVARS IN IRAN

Abstract

Trifolium species and cultivars are considered important forage crops iran ,
growing throughout the country. The present article considered the karyotypic details
of Trvulim taxa using multivariate statistical analysis. Taxa studied included:
Trifolim restylinatum (six populations: Shazand, Soriyan, Kordestan, Harati, Enaj
and Lordegan), T. repense, T, fragverm, T. prateme and T, alexandrinm. Somatic
chromosome numbers from 2n=14 in T. prateme to 2n=32 in T. repeme. Most of the
chromosomes were of m type with a few M and sm. Only in T. pratense was a single
subtelocentric (st) chromosome observed. Karl Pearson coefficient of correlation for
karyological data showed occurrence of structural changes in chromosomes. Statistied
analysis of data based on a factorial experimentreveafed a significant difference in the
size of chmmosomes in taxa studied. Factor analysis followed by Varimax rotation
showed that chromosomes 2,s and 5 are the chromosomes which undergo extensive
changes during genomic differentiation in the Trifulium taxa studied. Cluster analysis using UPGMA and WARD methods as well as ordination of the taxa on the first two prinvipal component axes produced five distinct clusters indicating genomic differences among taxa studied. Data obtained can be used in further breeding programs.