Pear cultivars fight fireblight
Updated: Friday, February 18, 2011 12:38 PM
Breeder hopes candidate replaces Bartlett as top pear
By JOHN SCHMITZ
For the Capital Press
Three promising pear cultivars that rival Bartlett for flavor and are resistant to its No. 1 nemesis will be evaluated in the Northwest starting in 2013.
"I'm hoping (Washington State University apple breeder) Kate Evans will agree to evaluate them in Wenatchee," said USDA Agricultural Research Service pear breeder Richard Bell, who works at the agency's Appalachian Fruit Research Station in Kearneysville, W.Va.
The prospective cultivars, which are crosses between Bartlett and other varieties with much higher fireblight resistance, will also be evaluated at Oregon State University's Mid-Columbia Agricultural Research and Extension Center in Hood River.
Fireblight is a disease in pear and apple orchards that can wreak particular havoc on Bartletts. Some of the previous cultivars that Bell has developed are moderately to highly resistant to the bacteria.
In addition to high fireblight resistance, the three new cultivars, when compared to Bartletts, also do a better job fending off postharvest diseases and are more precocious.
The advanced selections come close to equaling Bartlett's aroma, and are the same size. Two additional seedling families are in an earlier phase of evaluation and a third was produced for the purpose of developing cultivars with resistance to pear psylla, Bell said.
Prior to the evaluation process, the advance selections will be virus tested at WSU's Clean Plant Network facilities in Prosser, which will also be the primary source for budwood if and when the cultivars are released by USDA. USDA's West Virginia research station will serve as a backup source.
He said it would be around 2020 before nurseries are given bud wood to propagate further. Nurseries would take an additional two years to ramp up production.
Whether royalties will be added to the nursery prices is uncertain at this time, said Bell. "That depends on whether or not we patent (the cultivars). In the past USDA has not patented fruit varieties, but now that decision is made on a case-by-case basis."
If Bell has his wish, one or more of the cultivars will eventually replace Bartlett as the world's most popular pear variety.
"That's our hope: that we can produce varieties that combine the best fruit quality and production traits with fireblight resistance," Bell said.
While the new Bartlett-cross cultivars are similar to Bartletts, Bell said they the traits are not identical for all genes.
"Because pears don't breed true to seed, it's really difficult to completely recover all of the (desirable) characteristics of the Bartlett," he said. "But through a long process you can concentrate the genes you want over several generations."
Several years ago, Bell, who has a doctorate in plant breeding and genetics from Purdue University, began breeding new pear rootstocks with an eye towards developing dwarfing rootstocks that promote earlier fruiting.