Origin and dissemination route of pear accessions from Western China to abroad based on combined analysis of SSR and cpDNA markers

To understand the route of western China to abroad pear, total 131 pear accessions from China and Europe were used to detect and understand the genetic diversity, phylogenetic relationship genetic route based on SSR and cpDNA markers. The (Ho of western China accessions was 0.65 while Ho of abroad accessions was 0.57); Total accessions were distributed into two population using UPGAMA method, PCoA and structure analysis The trnS-psbC 1534 bp was highest and trnL-trnF-2 417–431 bp was lowest gained from combined cpDNA sequences. A total of 15 haplotypes were found. The haplotype diversity and nucleotide diversity was Hd 0.7969, and Pi 0.00158 respectively and the average number of nucleotide differences was K 6.944. China accessions had H-2 to H-15 haplotypes while P. communis accessions only had H-1 to H-6 haplotypes based on cpDNA markers, so oriental pear accessions had more wide range of the genetic diversity than abroad pear accessions; One large deletion was found in intergenic regions of accD-psaI in H-8 and H-9 by mv 1 using MEGA 7.0; 17 chloroplast DNA haplotypes were identified into two major types (type A and type B) by Median-joining Network using five cpDNA markers. In this study, combining the above results, it is considered that western China and abroad pears in two geographical locations had significant differences and also demonstrated that western China and abroad pears were historically, genetically and geographically different from each other based on the both useful tools of SSR and cpDNA markers; China Xinjiang might be an important place for pears to spread from the East to the West, and gene traveling happened in this route.