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Research Project: Management of the National Collection of Carya Genetic Resources and Associated Information

Location: Crop Germplasm Research

2018 Annual Report

1a. Objectives (from AD-416):
Objective 1: Efficiently and effectively acquire Carya genetic resources; maintain their safety, genetic integrity, health and viability; and distribute them and associated information worldwide. Sub-objective 1A: Acquire high priority Carya genetic resources, characterize them using molecular profiling methods, integrate them into secure, temporary maintenance systems, and distribute associated information and appropriate propagules worldwide. Sub-objective 1B: Revise diagnostic methods for detecting Xylella fastidiosa in Carya. Sub-objective 1C: Screen ex situ and in situ Carya populations for Xylella fastidiosa. Sub-objective 1D: Confirm efficacy of remediation methods to eliminate Xylella fastidiosa from nuts and/or scions of Carya. Objective 2: Develop more effective genetic resource conservation, evaluation, and characterization methods and apply them to priority Carya genetic resources. Record and disseminate evaluation and characterization data via GRIN-Global and other data sources. Objective 3: With other NPGS genebanks and Crop Germplasm Committees, develop, update, document, and implement best management practices for Carya genetic resource and information management.

1b. Approach (from AD-416):
This project represents one of the eight National Clonal Germplasm Repositories in the National Plant Germplasm System. It shares the common mission of all clonal repositories to collect, maintain, evaluate, document, and distribute valuable plant genetic resources. It is unique in its focus on the Carya genus, which includes the most valuable nut tree native to North America, the pecan [Carya illinoinensis (Wangenh.) K. Koch]. This project is a sister project of the Pecan Breeding Program (3091-21000-039-00D) and furnishes diverse Carya germplasm for use as parents within that program, as well as to other domestic and international breeding programs. Other North American species of Carya do not provide economic incentive for commercial nut production, but are valuable components of their ecosystems and are represented for use in breeding, with increasing interest on endemic and microbiotic associations. All diploid Carya, including commercially valuable Asian species, hybridize with pecan. Some Carya species exist only as fragmented populations in threatened habitats. Strategies for the appropriate characterization and utilization of those species are addressed in this project. Molecular genetic tools have been developed by the precursor project. These tools will continue to be cooperatively developed, refined, and applied by the current project in order to understand genetic diversity and gene flow in native populations, to verify identity of individual cultivars, to confirm parentage in controlled crosses, and to facilitate management of the Collection and its knowledgeable deployment.

3. Progress Report:
This is a new project that replaced 3091-21000-036-00D and which is continuing and expanding upon the work of the precursor project. Work under this new project in FY 2018 addressed all three objectives in relation to FY 2019 milestones. Graftwood of two early cultivars ('Kennedy' and 'Randall') significantly linked to the domestication history of the pecan were located, obtained, and grafted at both worksites of NCGR-Carya (Objective 1). An invitation to visit Laos in early FY 2019 is being pursued as a preliminary exploration for the rare Asian species Carya poilanei (Objective 1). Phenotypic observations of symptom expression related to Xylella fastidiosa were made on repository accessions, with some samples being submitted to state diagnostic labs for analysis, and others being sampled, extracted, and stored using revised methods (Objective 1). Multiple cooperators were engaged in FY 2018 in studies focused on evaluation of tree form in diverse provenance plantations using remote sensing by unmanned aerial vehicles, with imaging by both LiDAR and standard red/green/blue digital photography (Objective 2). Coordination of data entry methods with other NPGS genebanks (U.S. National Arboretum and Subtropical Horticulture Research Station, Miami), in cooperation with pecan industry cooperators, were undertaken in FY 2018 (Objective 3).

4. Accomplishments