WSU Researcher Maps the Tree Fruit Genome Mosaic

PULLMAN, Wash. — Better apples, peaches, pears and cherries at market sooner. That is one benefit of research by Washington State University bioinformaticist Dorrie Main.

Piece by piece, Main is mapping the DNA mosaic of the rosaceous family, which includes Washington’s largest crop – apples – and other tree fruit as well as cherries, peaches, berries and nuts. One result of that work is a shortening of the time between breeding-improved tree fruit varieties and actually planting them for production.

Main focuses on genes connected primarily to fruit quality – sugar and acid levels, color, firmness and fruit size – as well as other useful traits such as cold hardiness, disease resistance and post-harvest decay. DNA- based markers for genes with these traits give orchardists the ability to pre- select seedlings that contain the improvements, which shortens the time it takes to develop commercially acceptable varieties.

“We’re working on speeding up the time to crop improvement, which will enhance the productivity and competitiveness of Washington fruit tree growers,” she says. “In collaboration with other WSU researchers, breeders and growers, this research will help generate a population of new apple and cherry cultivars with desirable traits much more quickly.”

A self-identified “data miner”, she uses a 128-processor computer to analyze and house data for the Genome Database for Rosaceae, the international repository for all genetic information currently available about the family.

“Basically, we take the raw data generated by researchers worldwide and try to make sense of it,” said Main, who is an associate professor of horticulture and a scientist in the WSU Agricultural Research Center. “We take all of the known genes in the public gene bank and analyze them based on function. We are looking at 250,000 gene fragments and pulling out what’s meaningful.”

In terms of economic volume, the rosaceae family is the third most important family in the U.S. and other temperate regions of the world. Its aggregate wholesale value in the United States is approximately $7 billion.

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