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United States Department of Agriculture

Agricultural Research Service

Title: Molecular Fingerprints Identify Historic Pear Trees in US National Parks

Authors
item Bassil, Nahla
item Postman, Joseph
item Hummer, Kim
item Dolan, Susan - USDI NPS
item Lawliss, Lucy - USDI NPS

Submitted to: Pear International Symposium
Publication Type: Abstract Only
Publication Acceptance Date: January 20, 2007
Publication Date: January 20, 2007
Citation: Bassil, N.V., Postman, J.D., Hummer, K.E., Dolan, S., Lawliss, L. Molecular Fingerprints Identify Historic Pear Trees in US National Parks. Pear International Symposium. p. 41.

Interpretive Summary: The U.S. Department of Interior, National Park Service (NPS) has developed conservation plans for historic orchards within National Park boundaries. Variety identification of significant fruit trees is an important part of these plans. The U.S. Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository (NCGR), in Corvallis, Oregon uses DNA fingerprints to identify fruit varieties. These two agencies are collaborating to identify historic pear trees in U.S. National Parks. The San Juan Island National Historical Park north of Seattle, Washington, contains several remnant orchards with large surviving European pear trees planted in the late 19th to early 20th centuries. The Manzanar National Historic Site in Independence, California, a former detention site for Japanese-Americans during World War II, and the John Muir National Historic Site in Martinez, California also include old pear trees. Leaf samples were collected from 31 pear trees at these three parks in May, 2006 and sent to the USDA genebank in Oregon for analysis. The DNA was extracted from these samples as well as from several known pear cultivars growing at the USDA NCGR that were suspected to be identical to NPS pears, or that were available from nurseries at the time these locations were settled. Four pear trees growing at the English Camp at San Juan NHP had fingerprints identical to ‘Pound Pear’. Four other San Juan NHP pears were found to be identical to ‘Bartlett’ and one was identical to ‘White Doyenne’. Three pear trees at San Juan NHS were identical to each other, but did not match any of the control cultivars. Seven pear trees at John Muir NHS and Manzanar NHS were also indistinguishable from ‘Bartlett’ and two other trees not identified but were identical to each other. About 20 pear trees remain in an orchard where John Muir was buried in 1915 and are now a part of the National Historic Site. A large tree growing by his gravesite was confirmed as ‘Bartlett’. DNA fingerprinting is a very promising technology for rapid identification of historic fruit trees even when no fruit is present. As additional pear accessions at the USDA genebank are fingerprinted and added to the database, matching unknown trees with their true identity will be easier.

Technical Abstract: The U.S. Department of Interior, National Park Service (NPS) has developed conservation plans for historic orchards within National Park boundaries. Variety identification of significant fruit trees is an important part of these plans. The U.S. Department of Agriculture, Agricultural Research Service, National Clonal Germplasm Repository, in Corvallis, Oregon uses DNA simple sequence repeat (SSR) markers to fingerprint fruit varieties. These two agencies are collaborating to identify historic pear trees in U.S. National Parks using SSR fingerprints. The San Juan Island National Historical Park north of Seattle, Washington, contains several remnant orchards with large surviving European pear trees (P. communis L.) planted in the late 19th to early 20th centuries. The Manzanar National Historic Site in Independence, California, a detention site for Japanese-Americans during World War II, and the John Muir National Historic Site in Martinez, California also include old pear trees. Young leaf samples were collected from 31 pear trees at San Juan NHP, John Muir National Historic Site and Manzanar NHS in May, 2006 and sent to the USDA genebank in Oregon for analysis. DNA was extracted and microsatellite fragments were amplified using 11 SSR primer pairs. Several known pear cultivars were also included that were suspected to be identical to NPS pears, or that were available from nurseries at the time these locations were settled. Four pear trees growing at the English Camp at San Juan NHP had SSR fingerprints identical to ‘Pound Pear’. Four other San Juan NHP pears were found to be identical to ‘Bartlett’ and one was identical to ‘White Doyenne’. Three pear trees at San Juan NHS were identical to each other, but did not match any of the control cultivars. Seven pear trees at John Muir NHS and Manzanar NHS were also indistinguishable from ‘Bartlett’ and two other trees not identified but were identical to each other. About 20 pear trees remain in an orchard where John Muir was buried in 1915 and are now a part of the National Historic Site. A large tree growing by his gravesite was confirmed as ‘Bartlett’. DNA fingerprinting using SSR is a very promising technology for rapid identification of historic fruit trees even when no fruit is present. As additional pear accessions at the USDA genebank are fingerprinted and added to the database, matching unknown trees with their true identity will be easier.

Last Modified: 9/23/2014