title: Genetic structure and diversity of the wild Ussurian pear in East Asia.
abstract: The Ussurian pear is the most important cultivated pear in the northern part of China. Cultivated Ussurian pears are considered to have derived from Pyrus ussuriensis Maxim. which is native to the northeast of China. In Japan, two varieties of P. ussuriensis, P. ussuriensis var. aromatica and var. hondoensis are native to the northern area and the central area of the main island respectively. In order to reveal the origin of Pyrus ussuriensis var. aromatica distributed in the northern area of main island of Japan, more than 40 explorations have been performed in Japan and in China, and more than 30 natural habitats were recognized. These natural habitats are at risk of extinction because of human development and forest degradation caused by climate change. Population structure and genetic diversity of P. ussuriensis in China and P. ussuriensis var. aromatica in Japan have been investigated using both morphological and molecular markers in order to define appropriate conservation units, and to provide a good focus for conservation management. Distant evolutionary relationships between P. ussuriensis Maxim. in China and P. ussuriensis var. aromatica in Japan inferred from population genetic structure and phylogenetic analysis are also discussed.
authors.affiliation: Food Resources Education and Research Center, Faculty of Agriculture, Kobe University , 1348 Uzurano, Kasai, Hyogo 675-2103 , Japan.
authors.forename: Hironori
authors.initials: H
authors.lastname: Katayama
authors.affiliation: Food Resources Education and Research Center, Faculty of Agriculture, Kobe University , 1348 Uzurano, Kasai, Hyogo 675-2103 , Japan.
authors.forename: Hitomi
authors.initials: H
authors.lastname: Amo
authors.affiliation: Paulownia Research and Development Center of China, Non-timber Forestry Research and Development of CAF , Weiwu Road, Zhengzhou City 450003 , China.
authors.forename: Tana
authors.initials: T
authors.lastname: Wuyun
authors.affiliation: Botanical Gardens, Graduate School of Science, Osaka City University , 2000 Kisaichi, Katano, Osaka 576-0004 , Japan.
authors.forename: Chiyomi
authors.initials: C
authors.lastname: Uematsu
authors.affiliation: NARO Institute of Fruit Tree Science , 2-1 Fujimoto, Tsukuba, Ibaraki 305-8605 , Japan.
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Iketani
keywords: Pyrus ussuriensis; Pyrus ussuriensis var. aromatica; SSR; Ussurian pear; conservation; introgression; population genetics