Epsilon Open Archive

Abstract

A wide diversity of cherry varieties are collected in the Latvian and Swedish genetic resources collections, which consists of landraces and selections of local breeders, adapted to the local climate and growing conditions (winter hardy and disease resistant) as well as germplasm that results from years of scientific exchange and co-operation with the world’s leading plant research institutes. The introduction of this material into the breeding programs is largely dependent on the level of characterization. The genetic diversity and internal structure of Latvian and Swedish sweet and sour cherry genetic resources collections has been investigated using phenotypical characterization and evaluation in combination with SSR and self-incompatibility gene specific molecular markers. Phenotypical and molecular characterization revealed high phenotypic and genetic diversity of analysed germplasm as well as the relatedness of Baltic and Scandinavian sweet and especially sour cherry landraces which indicates a possible common historical origin. Local Baltic-Scandinavian cherry varieties were also differentiated from other cherry germplasm by the frequency of self-incompatibility alleles detected using gene specific molecular markers. Self-incompatibility allele information gained from this study will be also useful in breeding programmes for the planning of crosses and conservation of alleles. The use of different characterization methods of cherry genetic resources also facilitated methodological observations, applicable to cherry germplasm characterization. It was concluded that thorough evaluation of genetic diversity and internal structure of cherry genetic resources collections should include both phenotypic and molecular characterization. The information of genetic relatedness revealed by SSR markers did not show direct correspondence with the relatedness information detected by phenotypic characterization, regardless of the number of analysed markers. Therefore a sufficient preliminary description of cherry genetic resources and discovery of internal genetic relatedness of germplasm could be obtained by using phenotypic description in combination with a small set of highly polymorphic SSR markers in combination with available gene specific markers.