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.

Native fruit tree genetic resources in Japan

“…Whether this species began to be used before or after introgression is still unknown. This is discussed in more detail by Katayama (2016) in this issue.…”

Crop Load Management in Nashi Pear—A Review

“…European cultivars all belong to the species P. communis. Cultivated species of Asian pears include the Ussurian pear (P. ussuriensis Maxim), Chinese white pear (P. × bretschneideri Rehder), Chinese sand pear and Japanese pear (P. pyrifolia Nakai) and Xinjiang pear (P. sinkiangensis Yu) [4,5]. Bao et al [4] suggested that the progenitor of Japanese pears originated from China.…”

Evaluation of genetic variations and phylogeny of the most popular pear (Pyrus communis L.) cultivars in Duhok city using AFLP markers

“…Pear (Pyrus spp.) is one of the economically and nutritionally valuable and popular rosaceous fruit crop being cultivated in temperate climates, it originated in the mountain regions of south-western China and have spread all over the world (1,2). It considered as the third most significant fruit crop after grapes and apples in temperate areas (3).…”

“…The genus Pyrus (2n = 34 chromosomes), which belong to the tribe Pyreae, subfamily Pomoideae in the Rosaceae family, is widely distributed on six continents particularly in Asia, Europe, and Africa (3,5,1,6). Classically, based on domestication and the geographical distribution, Pyrus species are divided into two major native groups.…”

“…This technique has many advantages over the other molecular methodologies such as RAPD and SSR, due to its power to generate high number of polymorphic and informative bands per reaction with high reproducibility of banding patterns. This is mainly because of its higher specificity in the primer annealing to their corresponding complementary adapters (10,1). Due to the lack of comprehensive molecular characterization and diversity analysis of pear in the region, the AFLP technique was implemented in this study to molecular characterize and to assess the genetic diversity and phylogenetic relationships between pear cultivars in Duhok city.…”