Apple breeder Dr. Kate Evans says sequencing of the human genome led to huge advances in genomics and development of technologies and tools that can be applied to other genomes, such as apple.Washington State University plans to release the first apple fr
Washington State University plans to release the first apple from its breeding program this year. But with the variety still going through the patenting process, the university is keeping it under tight wraps.
The new variety is one of nine elite selections derived from WSU’s apple breeding program, which was launched by horticulturist Dr. Bruce Barritt in 1994.
Those selections have gone through two levels of screening as seedlings at WSU. Four were planted in commercial orchards around the state in 2007, and the other five were planted in orchards a year later. They have also gone through sensory profiling at WSU to see how they compare with existing varieties, and they were taste tested by the industry at large during the Washington State Horticultural Association’s convention in Yakima in December.
Barritt, who retired from WSU last year, is still involved in the release of the new variety, but Dr. Kate Evans now heads the breeding program and has inherited from Barritt another 40,000 trees that are in the process of evaluation and 45,000 crosses that are in various stages of development—from seeds that are just germinating to seedlings growing in the nursery.
Pome fruit breeder
Evans was previously the pome fruit scion and rootstock breeder at the famous East Malling Research in the United Kingdom. She moved to Wenatchee, Washington, last fall with her husband, Peter Smytheman, and their four children.
She earned a doctorate in plant molecular biology from the University of Durham in England and joined East Malling in 1992, working with breeder Dr. Frank Alston, who developed the Concorde pear and the Fiesta apple.
Evans took over from Alston when he retired in 1996. In the United Kingdom, it was difficult to obtain funding for traditional breeding, she recalled, but European funding was available to develop tools to help breeders, such as molecular markers that are used to test progeny for desirable traits. Evans was involved in several projects relating to molecular biology.
The program she managed at East Malling released two apple varieties: Saturn (the first disease-resistant apple developed at East Malling) and Meridian (a Cox-type apple), as well as two rootstocks, the disease-resistant MM.116 for apples and the EMH quince rootstock for pears.
She served on an advisory committee for the National Fruit Collections at Brogdale in the United Kingdom and managed a project to genetically fingerprint the material in the collections.
Evans said she was interested in succeeding Barritt at WSU because of the world-class team of scientists working at WSU on genomics of rosaceous plants, including genomicists Drs. Cameron Peace and Amit Dhingra, who are working on molecular markers; Dr. Dorrie Main, who runs the Genome Database for Rosaceae; and Nnadozie Oraguzie, stone fruit breeder.
"In terms of that team, I think it makes WSU the hottest place to move on apple genomics internationally," she said.
European researchers began mapping the apple genome in 1992. The collaborative effort, which later involved scientists from around the world, including WSU, is almost complete. Sequencing of the apple genome will allow scientists to design more accurate markers that are closely linked to traits of interest and are easy to use, Evans said.
Texture
The focus of WSU’s breeding program has been to develop varieties specifically for Washington. As a result, texture has been considered the most important attribute, whereas disease resistance might be more critical in other growing areas, such as Europe.
"The program here has been using markers for texture and storability, which I think puts it ahead of other breeding programs internationally," Evans said, noting that markers for traits such as disease resistance were relatively easy to develop.
Texture will continue to be a primary focus of the WSU program, she said, and the university’s scientists are working to develop more efficient and more accurate markers for desirable apple traits. Peace has been developing high-throughput screening systems and looking at the economics of using markers. Evans hopes to work with Peace to find the most practical and effective way to use markers in the program.
Markers can be used to screen individual seedlings to eliminate the undesirable ones before they are even planted out in the field, allowing a larger number of crosses to be made. This would improve efficiency, but wouldn’t necessarily reduce the length of time between making the cross and releasing the variety, Evans said, because selections would still need to be planted out at a range of sites to see how they perform.
Markers can also be used to screen potential parents for the crosses, which is what WSU has done in the past.
"The more you can characterize the genetics of the parents, then the more you know about which cross combinations would give you a better outcome, without having to screen all of the progeny," Evans explained. "It’s incredibly valuable to be able to do that."
Evans said she plans to increase the diversity of the parents used in the program, perhaps using unnamed varieties as well as well-known ones. In the early years of the program, Barritt used predominantly Fuji, Gala, Cameo, Splendour, and Pink Lady for the crosses.
Germplasm
WSU is planting a core collection of varieties from the U.S. National Apple Collection held at Cornell University, New York, as a future source of germplasm, and it might be possible to access material from the National Fruit Collections in the United Kingdom, she said.
In January, a WSU breeding program advisory council was formed. It is made up of the growers testing the elite selections and other industry people recommended by the Washington Tree Fruit Research Commission. Scientists Dr. Jim Mattheis, plant physiologist and research leader with the USDA’s Agricultural Research in Wenatchee, and Dr. Gene Kupferman, postharvest extension specialist, serve on the council. Brent Milne, horticulturist with McDougall Fruit Company, is the chair.
In addition to heading the apple breeding program, Evans hopes to study the feasibility of starting a pear rootstock breeding program at WSU. She’s also interested in breeding pear scions. The Washington pear industry has been pushing for the U.S. Department of Agriculture to move its pear breeding program from Kearneysville, West Virginia, to Washington State.
"I love pears," Evans said. "Pear breeding is much more of a challenge than apple breeding."
One of the difficulties is knowing when to pick the fruit for a proper assessment of the quality, she explained. "Everything’s slower, and everything’s more difficult with pears."
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