Genetic Differentiation of Red Clover (Trifolium pratense L.) Cultivars and Their Wild Relatives

Abstract

Biodiversity of red clover is changing. It is become more difficult to find new breeding material. Moreover, populations with predominant morphological features of cultivars are more frequently found in wild habitats. Therefore, it is important to identify genetic structure and diversity within and among wild populations and cultivars worldwide. During this research, seed samples from wild red clover (Trifolium pratense L.) habitats were collected in different Lithuanian sites in nemoral environmental zone. Subsequently, samples were germinated in greenhouse and randomly taken for genetic analyses. ISSR fingerprints of 339 genotypes from 13 populations and 5 varieties were analysed. Analysis of molecular variance (AMOVA) has shown high genetic variation within populations (83%). The highest polymorphism was identified in population pop2887 (PPL = 82.28%). Interestingly the polymorphism of varieties was high and ranged from 64.56 (‘Vytis’) to 83.54 (‘Liepsna’). Meanwhile, variance among populations was low—17%. Fixation index FST = 0.182 revealed high differentiation of the populations while gene flow was high with an exchange of 2.2474 migrants per generation. This revealed a high genetic diversity within populations and high gene flow between wild populations and cultivars in Lithuania.