Genetic Relationship and Standard SSR Set Selection in Pyrus for Korean Pear Genome Project

Pear (Pyrus spp., X=17) is one of the important fruit crops in Korea and three basic species, P. ussuriensis, P. pyrifolia and P. fauriei, are known as Korean native. For the purpose of practical applying the genomic data from the Korean pear genome to the efficient and precise breeding program in the fruit crops, new pear genome project has been started since 2012 for nine years plan (supported by Next-Generation Biogreen 21 program of Rural Development Administration, Korea). As a starting point of this genome project, identification of genetic relationship among Korean pears and selection of standard SSR set were conducted to apply core collection management and reference map construction. Depending on SSR profiling among basic pear species, P. ussuriensis was grouped in group IV with other major Asian pear species but P. pyrifolia was located in group VI including most of Japanese cultivars. Genetic relationship among Korean pear cultivars compared with their parents were also identified that they are closely related P. pyrifolia, P. ussuriensis and/or hybrid between two species. ‘Whangkeumbae’ and ‘Minibae’ were chosen as the representative cultivar of P. pyrifolia and P. ussuriensis in each among Korean pears. Total of 66 standard SSRs distributing through the 17 chromosomes were selected on ‘Whangkeumbae’, ‘Minibae’ and their progeny among published SSRs in pear and apple (Malus spp., X=17) genomes. These results will be shared and used for further progress on comparison with apple genome and development of marker assisted fruit breeding systems for other Rosaceae.