Genetic Diversity and Population Structure of Wild Pear (Pyrus communis L.) from Türkiye Using iPBS-Retrotransposon Markers

IIn this study, iPBS (Inter-Primer Binding Site) retrotransposon molecular markers were applied to wild pear (Pyrus communis L.) genotypes collected from the provinces of Iğdır and Kağızman for the first time to determine their genetic diversity and population structure. In the study, a total of 97 bands were obtained using 11 iPBS primers; 62.89% (61 bands) of these bands were found to be polymorphic. An average of 5.54 bands per primer was obtained, and the average PIC value was calculated to be 0.74. The average Nei's gene diversity (h) was determined to be 0.25, while the Shannon information index (I) was found to be 0.39. The pairwise genetic similarity coefficients calculated according to the Jaccard index were found to be highest at 0.875 (K5-K10) and lowest at 0.142 (K1-I5). The UPGMA dendrogram divided the 45 accessions into four main groups; however, the groups did not exhibit a homogeneous structure in terms of geographical origin. Principal Coordinate Analysis (PCoA) also could not separate the genotypes according to their geographical origins. The results of the AMOVA showed that 94% of the total variance was caused by differences within populations, while only 6% was caused by differences between populations. The Bayesian clustering analysis indicated that the most probable number of clusters is K=2, with each cluster consisting of a combination of the Iğdır and Kağızman genotypes. The results show that the 45 pear genotypes have a moderate amount of genetic diversity and that iPBS-Retrotransposon markers can be used well in studies of pear genetic diversity.