Genetic diversity and population structure in bearded iris cultivars derived from Iris × germanica L. and its related species I. pumila L., I. variegata L., I. pallida Lam.

Abstract

Bearded irises are horticulturally important worldwide. Molecular assessment of the germplasms is helpful for their scientific utilization. In this study, forty bearded iris cultivars derived from Iris × germanica L., I. variegata L., I. pumila L. and I. pallida Lam. were selected to characterize their genetic diversity and population structure using AFLP markers. 568 bands were generated, of which 479 (84.3%) were polymorphic. The genetic distances among accessions ranged from 0.20 to 1.09, with an average of 0.52. Six clusters could be obtained by cluster analysis, which was generally in accordance with the color performances of tepals. In PCoA analysis, the first two principal co–ordinates accounting for 17.49% and 13.75% of the total variation revealed closer relationships among I. × germanica, I. variegata and I. pallida, whereas I. pumila was further. Five sub-populations could be detected by structure analysis. The findings provide an insight into the germplasm innovation for bearded irises.