Genetic Diversity of Asian and European Pear Using Simple Sequenced Repeats Markers Analysis

Twenty-six European pears (P. amygdaliformis, P. communis, P. elaeagrifolia, P. nivalis), 18 Asian pears (P. pyrifolia, P. serotina), and 4 hybrids (P. communis x P. pyrifolia) were classified and identified using seven simple sequenced repeats (SSR) markers. Seven markers in this study displayed informative polymorphisms, of which six were obtained from 'Whangkeumbae' (P. pyrifolia) using fosmid library sequences. Pair-wise genetic distances based of the F statistics of Nei and Li revealed an average distance of 34.4% among European pear cultivars and 44.2% among Asian pear cultivars. Unweighed pair-group method of arithmetic averages cluster analysis results were classified into two main groups. The first group included Asian pear (P. pyrifolia) including P. serotina and some hybrids. The second group contained European pear (P. communis) and also P. nivalis. P. amygdaliformis was on the outside of it. The genetic distance of P. elaeagrifolia was closer to P. communis. Four hybrid cultivars were divided in two groups. 'Oharabenni' and 'Kiyomaru' were clustered with P. communis and 'Greensis', 'OH x Nijisseiki' were P. pyrifolia. In conclusion, genetic analysis using these 7 SSR markers seemed to be make it possible to distinguish European and Asian pear (P. pyrifolia).