The Genome of Pear (Pyrus bretschneideri Rehd.)

Pear (Pyrus spp.) is one of the leading cultivated fruit trees of temperate regions, and it belongs to the subfamily Pomoideae in the family Rosaceae. The majority of cultivated pears are functional diploids (2n = 34).  As a popular fruit in the world market, pear is widely cultivated on six continents with major production in China, USA, Italy, Argentina, Spain, Korea, Turkey, South Africa, Japan and Belgium. As the top ranked production country, China produces more than 60% of the world pear production. Pears are among the oldest of the world’s fruit crops, likely to have originated during the Tertiary period (65–55 million years ago) in the mountainous regions of southwestern China.

Led by the pear engineering technology research center of Nanjing Agricultural University in China, the international pear genome organization recently completed the first comprehensive fine pear genome after two years of sequencing, assembly and annotation. The data has been released through professional website http://peargenome.njau.edu.cn since May 25th, 2012. Herein, we report on a high quality draft genome sequence of the diploid P. bretschneideri Rehd. cv. Dangshansuli (also known as Suli), the most important commercial Asiatic pear cultivar grown in the world (4 million ton per year), using BAC-by-BAC strategy. A total of 97.1% of the estimated whole genome size has been assembled. These assembled scaffolds have been aligned and oriented to their corresponding 17 chromosomes using a high-density genetic map. The sequence of the pear genome provides an invaluable new resource for comparative genomic studies in Rosaceae and biological research of Pyrus.