Genetic diversity assessment in winter oilseed rape (Brassica napus L.) collection using AFLP, ISSR and SSR markers

Abstract

The genetic diversity of 94 accessions of winter oilseed rape (Brassica napus L.), representing past and contemporary material utilized in the Czech breeding programmes, was determined using microsatellites (SSRs), ISSRs and AFLPs. All three kinds of markers differed in the range of observed polymorphism and differentiated clearly each accession. Altogether 89 SSR, 1003 AFLP and 53 ISSR markers were evaluated. Their average rates of polymorphic bands were 100%, 53.9% and 90.6%, respectively, indicating high genetic diversity among the accessions. The greatest genetic distance was found by ISSRs (62.3%) whereas significantly lower distances of 49.4% in SSRs and 35.5% in AFLPs were observed. The genetic similarity matrix clearly distinguished all accessions. A set of the most distinct varieties was established. The analysis of the genetic pattern of the accessions indicated two groups comprising most of the modern Czech breeding materials, revealing a distinct shift in breeding. Surprisingly, molecular analyses did not support  breeders’ views about a narrow genetic base of the Czech breeding materials. The choice of appropriate technology for different aspects of germplasm evaluation is also discussed.