U. ILLINOIS (US) — An international team has sequenced the genome of the Asiatic pear, a species native to China.
“We ended up with an assembly that’s over 97 percent correct rather than 50 or 60 percent,” says University of Illinois plant molecular geneticist Schuyler Korban, whose lab was involved in a consortium that previously sequenced the woodland strawberry genome.
“Sequencing technologies have improved over the years, and we’ve learned from previous strategies and have used a more effective and efficient approach for sequencing pear. The cost as well is definitely lower than when genome sequencing first began,” adds Korban.
The project was developed when Jun Wu, a professor at Nanjing Agricultural University in China, spent a year in Korban’s lab to work on genetic diversity and global gene expression analysis of pear using University of Illinois apple molecular markers and the apple microarray.
“During Wu’s stay in my lab, we met with her group leader Professor Shaoling Zhang, who led this effort, and others who visited us, and we discussed working together on sequencing the pear genome. ”
China is the top producer of pear, almost accounting for 60 percent of the world production. “The pear actually originated in China 65 million years ago,” Korban says. “It’s the center of the origin of pear, just like most fruits are. China is rich in germplasm.”
Korban notes that there are two major types of pear: European and Asiatic. The sequencing was actually done on the Asiatic pear.
“The Asiatic pear looks nothing like the European pear, for example the Bartlett pear,” Korban explains.
The European pear is the more familiar pear-shaped fruit, but the Asiatic pear is a round fruit that looks like a yellow apple and is often advertised in US grocery stores as an “apple pear.”
“The Asiatic pear is the most important commercial pear in China,” Korban says. “It’s sweeter, has a high level of antioxidants, and is healthy like the apple, but it is higher in lignified cells so when you bite into it, you can feel the grittiness, making it higher in fiber. It’s also more resistant to diseases including fire blight, which most of the European pears are susceptible to.”
“The knowledge of the pear genome will greatly facilitate comparative genomics studies for identification of genes of consumer and grower interest in the Rosaceae family,” says Awais Khan, a postdoctoral research scientist working in the Korban Lab. “Ultimately, this will lead to rapid improvement of these fruits for disease resistance and for fruit quality traits.”
In addition to Nanjing and Illinois, the international team included researchers from the Bejing Genomics Institute, Zhejiang Academy of Agricultural Sciences, University of Georgia, University of Hawaii, and Tohoku University.
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