S02 - Session O4 - II - Conservation and Characterization of the USDA National Pear Collection at the NCGR

Authors: Nahla V. Bassil *, Lauri Reinhold, Jason Zurn, Joseph Postman, Barbara Gilmore, Gabriel Flores, Gayle Volk, Maria Jenderek, Sara Montanari, David Chagne, Vincent Bus, Lester Brewster, Chris Dardick, Christopher Gottschalk, Charles-Eric Durel, Caroline Denance

The U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS) maintains 2,378 accessions of pear and 478 wild pear relatives in an orchard at the National Clonal Germplasm Repository in Corvallis, Ore. In the last five years, climate change has increased the incidence of fireblight in the collection. Accessions that are known to be susceptible to fireblight are preserved in deep pots in screenhouses and prioritized for back-up as cryopreserved dormant buds or shoot tips at the USDA National Laboratory for Genetic Resource Preservation (NLGRP), in Fort Collins, Colorado. A 70K single nucleotide polymorphism (SNP) array and two simple sequence repeat (SSR) fingerprinting sets are used for efficient management of this collection by identifying and eliminating duplicates and mis-labeled trees, and ensuring a diverse collection of true-to-type heritage cultivars and their wild relatives. Collaborative projects with pear researchers worldwide (INRAE, Angers, France, Plant and Food Research, New Zealand) include: comparing the SSR-based genotypes of important pear cultivars preserved at the NCGR across European collections to obtain a global view of heritage pear genetic resources; and developing diagnostic markers for fireblight resistance. Conservation and characterization of pear genetic resources at the NCGR is a global effort and will be discussed at the symposium.