AFLP Analysis of Genetic Diversity in an Association Mapping Panel of Lolium perenne L.

Abstract

Amplified fragment length polymorphism (AFLP) was used to measure genetic diversity in a panel of perennial ryegrass genotypes. The panel consisted of 90 cultivars, 38 ecotypes of Lithuanian origin and 65 ecotypes of Ukrainian origin. The three primer combinations used in the AFLP analyses amplified 227 fragments within the size range of 50–350 bp. Ecotypes formed separate clusters in a principal coordinate analysis (PCoA) according to their origin, while cultivars did not show any clustering pattern. Genotypes were separated into three groups (cultivars, Lithuanian ecotypes and Ukrainian ecotypes) to perform analysis of genetic variation within and between these groups. As expected, most of the variation (96.7 %) was detected within groups. Nei’s gene diversity (h) and Shannon’s information (I) indices had similar values (ranging from 0.2047 to 0.2094, and from 0.3247 to 0.3329, respectively), indicating similar amount of genetic diversity in all groups. The greatest genetic difference according to population pairwise F_ST and Nei’s genetic distance (D_N) indices was detected between Lithuanian and Ukrainian ecotype groups. Nevertheless, both genetic distance indices had rather small values (F_ST = 0.019–0.059; D_N = 0.0056–0.0147). In general, high genetic diversity and low differentiation between groups indicate that acquired panel of perennial ryegrass genotypes is suitable for further association studies.