Genetic diversity of Estonian-grown spring wheat varieties assessed by microsatellite and morphological analyses

Abstract

In order to select molecular markers suitable for the seed control practice, 12 regionally cultivated spring wheat varieties were analysed by 41 microsatellite markers (SSRs). The analysed group included a pair (‘Satu’-‘Helle’) and a triplet (‘Tjalve’-‘Vinjett’-‘SWEstrad’) of varieties derived from each other. A dendrogram resulting from analysis of the matrix of dissimilarities discriminated all varieties, and in full agreement with the pedigree data, the varieties were divided into three groups consisting of Nordic, German and Dutch varieties, respectively. In the genetically close Nordic subgroup, Swedish varieties ‘Vinjett’ and ‘SWEstrad’ could be distinguished only by three of the analysed 41 SSR markers. An attempt was made to analyse genetic diversity in the group on the basis of morphological characteristics evaluated according to the UPOV guidelines. The clustering of morphological data resulted in a dendrogram which agreed neither with the known pedigree data nor with the conducted SSR analysis. Multilocus SSR analysis revealed heterogeneity in the analysed plant material. In order to monitor inheritance of the detected heterogeneous or null-alleles, six breeding lines derived from the studied varieties were analysed. In two of the breeding lines, non-parental SSR alleles were detected. Outcrossing is suggested as a possible source of the inconsistent alleles. A minimal set of molecular markers needed to identify/verify a variety in a group can be composed of markers amplifying fragments unique in the group length. In this study, identifying markers were found for seven varieties of the group; the remaining five varieties could be identified in the group by combinations of two or three microsatellite markers.