Genetic Diversity and Infraspecific Relationships of Trifolium fragiferum L. in Iran

Abstract

Trifolium L. has around 255 species worldwide. Strawberry clover is one of the most valuable forage crops of the genus Trifolium with two varieties in Iran. In the current study, 40 individuals of eight natural populations of Trifolium fragiferum varieties were examined to reveal genetic diversity and infraspecific relationships with microsatellite markers. Based on five primer sets, a total of 11 alleles were obtained with an average of 2.2 alleles per locus. The polymorphic information content ranged from 0.0 to 0.517 with an average of 0.328. The observed and effective heterozygosity across all loci changed from 0 to 1 and 0 to 0.596, respectively. The gene diversity among the loci varied from 0 to 0.530. Unweighted pair group method with arithmetic mean analyses based on Gower’s distance coefficient grouped accessions into five major clusters but did not separate 40 individuals of T. fragiferum var. fragiferum and T. fragiferum var. pulchellum in distinct groups. Results did not show any clear association between clusters and the geographical origin of varieties. Analysis of molecular variance indicated 84% of the total variation within populations. Genetic differentiation was low in the total population (FST = 0.1), while a high level of gene flow (Nm = 2.247) was estimated among populations. Microsatellite markers evidence suggests that two varieties should not remain separated.