Chloroplast genome diversity of the Pyrus genus; from Iranian and European wild pear species to the cultivated cultivars.

The genome structure of chloroplast DNA (cpDNA) is highly conserved among the different species belonging to the Pyrus genus. In spite of the relevance of this genetic material for phylogenesis because of its maternal inheritance, molecular data on these species are very scanty. In order to investigate phylogenetic relationship in the genus Pyrus, we recognized three hyper variable regions in intergenic spacers of cpDNA of 73 Iranian and European pear (Pyrus communis L.) local cultivars and wild genotypes, plus 9 Japanese pear genotypes (Pyrus pyrifolia, syn. P. serotina) and one Chinese pear (P. × bretschneideri). CAPS markers were developed by digesting PCR products separately with 3 restriction enzymes and the relative patterns were used for a cluster analysis. Results evidenced that Iranian and European pear cultivars were divided into five groups, whereas Japanese pear cultivars were grouped together with Iranian pear genotypes. This evidence supports the hypothesis of a significant genetic contribution in the Iranian wild genotypes from Japanese pear, brought to this region in ancient times through the main routes of the Silk Road