Genetic diversity and population structure of wild pear (Pyrus pyraster (L.) Burgsd.) in Poland

Abstract

In order to provide molecular characteristics of wild pear (P. pyraster) resources, six populations (192 accessions) from different regions of Poland were investigated with 17 SSR loci. Each of the SSR loci used was polymorphic, with a mean of 19.5 alleles per locus and a mean PIC of 0.806. Both the high heterozygosity (Ho = 0.751) and low Fis (0.007) indicated that the wild pear populations maintain a relatively high level of diversity, while the mean Findex of 0.039 and the number of migrants per generation (Nm = 6.996) revealed a high gene flow and weak inter-population differentiation. AMOVA analysis located polymorphisms mainly within populations (96%). Genetic relations between populations did not show correlations with geographical distances. The dispersal influence of gene flow could be the reason of the disrupted relationship within populations and the low interpopulation differentiation. We did not find any evidence to support the hypothesis about influence of interspecies hybridization with pear cultivars on the level of wild pear population diversity.