摘要：Different life history traits affect the genetic structure of plant species. We investigated the impact of habit form on intraspecific genetic variation in ten Trifolium species, by randomly sampling ten genotypes of each species using inter-simple sequence repeats (ISSR). Six of eleven primers produced a total of 108 clear and reproducible polymorphic bands. Numbers and levels of polymorphic ISSR bands ranged from 18 and 16.67% in T. hirtum to 81 and 75% in T. hybridum, and intraspecific Nei's diversity ranged from 0.0599 to 0.2648 in these species. The polymorphic ISSR loci in annual species varied from 16.67 to 52.78% with a mean of 38.90%, and in perennials from 46.30 to 75.00% (mean 58.49%). The results indicate that intraspecific genetic variation in annuals is significantly lower than in perennials (P < 0.04, n = 10). The ISSR-based UPAGMA dendrogram based on Nei's distances supported the classification of sections proposed by internal transcribed spacer sequence data opposed to morphological characterization. It was confirmed that section Lotoidea is a monophyletic and section Trifolium is a polyphyletic group. The habits form affected the level of genetic diversity in plants
