Evaluating the Diversity of Ecotypes of Red Clover (Trifolium pratense L.) from Northwestern Spain by Phenotypic Traits and Microsatellites

For more than 50 years, the CIAM-AGACAL (Agricultural Research Centre of Mabegondo, Xunta de Galicia, A Coruña, Spain) has been carrying out the important task of conserving the phytogenetic resources of ecotypes and natural populations of grassland species from northwestern Spain. The CIAM-AGACAL’s germplasm bank has 57 populations of red clover (Trifolium pratense Lam.), one of the most cultivated forage legumes in the world. The goal of the present study was to evaluate the diversity among cultivars and natural clover populations at morphological and molecular level. Twelve polymorphic SSR loci revealed 241 microsatellite alleles with an average of 20.08 alleles per locus. Two main groups were detected by the Structure software, one of them including local populations and the second clustering cultivars and related populations. Intra-specific variability was found among cultivars and natural populations. A moderate genetic differentiation of Spanish red clover cultivars was observed (Fst = 0.08) between the two main clusters. Finally, a certain relationship between phenotypic and genotypic variation was detected.