Research Project: Management of Arid Land Plant Genetic Resources and Regeneration of Accessions with Special Climatic Requirements

Location: Office of The Director

2021 Annual Report

Objectives
The overall goal of this project is to leverage the long, dry growing season in Parlier, CA both to provide support to other National Plant Germplasm System (NPGS) collections through seed regeneration and back-up preservation, and to maintain a collection of crops suitable for arid land production. The unique climate at this site allows for seed production in specific accessions that cannot be regenerated at their priority sites. NPGS sites that routinely regenerate or back up accessions in Parlier include the National Clonal Germplasm Repository at Corvallis OR (NCGR-Corvallis), the Western Regional Plant Introduction Station in Pullman WA (WRPIS-Pullman), the National Small Grains Collection in Aberdeen ID (NSGC-Aberdeen), the North Central Regional Plant Introduction Station (NCRPIS – Ames, IA), the Plant Genetic Resources Unit at Geneva NY (PGRU-Geneva), and the Plant Genetic Resource Conservation Unit in Griffin GA (PGRCU-Griffin). This site also allows for the maintenance, seed production, and characterization of whole genera that cannot be maintained elsewhere. Specifically, during the next five years we will focus on the following objectives: Objective 1: In collaboration with other NPGS sites, efficiently and effectively regenerate accessions that require long growing seasons and/or arid conditions, and also serve as the back-up site for the NPGS Corylus genetic resources collection. Objective 2: Efficiently and effectively acquire genetic resources of arid land and industrial crops; maintain their safety, genetic integrity, health and viability; and distribute them and associated information worldwide. • Subobjective 2A: Expand the Parthenium collection through plant exploration, focusing on P. argentatum, especially diploid individuals. • Subobjective 2B: Regenerate seed stocks in the Parthenium, Limnanthes, Physaria, Paysonia, and Cucurbita foetidissima collections, emphasizing accessions with low germination or low seed supply. Prepare and send backup seed to the National Lab for Genetic Resources Preservation (NLGRP). Objective 3: Develop more effective genetic resource maintenance, evaluation, and characterization methods and apply them to priority genetic resources of arid land and industrial crops. Record and disseminate evaluation and characterization data via GRIN-Global and other data sources. Objective 4: With other NPGS genebanks and Crop Germplasm Committees, develop, update, document, and implement best management practices and Crop Vulnerability Statements for arid land and industrial crop genetic resource and information management.

Approach
Objective 1: Research Goal 1: Provide land, labor and expertise to plant, grow, harvest, clean and ship regenerated seed or other propagules to other NPGS sites. Approach: The purpose is to support the maintenance of high-quality genetic resource material throughout the NPGS system. Objective 2: Research Goal 2: Implement best management strategies for the acquisition, maintenance, and distribution of the genetic resources of the NALPGRU. Rationale Statement: This objective describes three of the four basic tenets of the mission of the NALPGRU of acquisition, maintenance of the germplasm, and distribution of high quality, healthy, viable, true-to-type genetic resources to the domestic and international scientific and educational communities. The fourth tenet is evaluation and characterization covered in Objective 3. • Subobjective 2A: Expand the Parthenium (guayule) collection through plant exploration, focusing on P. argentatum, especially diploid individuals. Research Goal 2A: Increase the level of genetic diversity in the NALPGRU collections. Approach: The purpose is to acquire new genetic resources to fill critical gaps in the collection. Objective 3: Research Goal 3: Improve maintenance techniques, develop phenotypic descriptors for crops lacking them, and use the descriptors for evaluation and characterization. Approach: This objective describes making collection maintenance more effective and is well aligned with the maintenance portion of Objective 2. Evaluation and characterization of the collections increases the visibility and usefulness of the collections to the stakeholder community. Phenotypic descriptors are very useful to help guide breeders and others toward accessions that will best advance their programs. Phenotyping is a focus of the NALPGRU. Objective 4: Research Goal 4: Regularly document best management practices and update Crop Vulnerability Statements every three to four years. Approach: This objective describes developing updated and documented best management practices for grow-outs and collection management and evaluation.

Progress Report
This report documents progress for the project 2034-21000-012-00D, “Management of Arid Land Plant Genetic Resources and Regeneration of Accessions with Special Climatic Requirements,” which began in 2018 and continues work from parent project 2034-21000-011-00D, “Management of Arid Land Plant Genetic Resources and Associated Information.” In 2021 we continued to support the mission of the National Plant Germplasm System (NPGS) by maintaining, evaluating and distributing accessions of arid-land industrial crops and providing a long season regeneration site for accessions with special climatic requirements from other NPGS sites. Progress toward Objective 1 was in two main areas: regenerations for other sites and serving as the backup site for the national hazelnut collection. We served other NPGS sites by regenerating annual accessions that cannot produce seed at their home sites because they do not have a long enough growing season or suffer excessive pest or disease pressure due to climate. The process is executed from receipt of seed at the beginning of the growing season, through planting in the greenhouse, transplanting to the field (unless the seed is sown in the field directly), isolating from pollinators (if necessary), harvesting, and shipping increased seed back to the home site. This includes frequent coordination with the curators of these crops and photo updates, some of which are used to add to the available descriptors on the Germplasm Resources Information Network (GRIN-Global). Regenerations planted during fiscal year 2021 for other NPGS sites included 256 garlic, 1156 small grains, 15 warm weather squash, 15 winter squash, and 42 sunflower accessions. The hazelnut backup collection from Corvallis, Oregon, is being reestablished with newly propagated plants. New plantings are currently on hold due to the retirement of the hazelnut curator and will resume when the position is refilled. This backup planting serves as security from the growing threat of filbert blight disease in Oregon. Objectives 2-4 focus on the maintenance, acquisition, evaluation and distribution of a collection of arid-land industrial crops. Our priority crops are a combination of clonal accessions (prickly pear, jojoba) and seed propagated accessions (meadowfoam, bladderpod, guayule, buffalo gourd). As of July 2021, we have shipped 21 orders for germplasm from our site to domestic and international researchers. We prepared and shipped seed lots of guayule (Parthenium) and bladderpod (Physaria and Paysonia) to ARS researchers in Ft. Collins, Colorado, for security duplication and critical backup. As part of a collaboration with scientists at the University of Nevada, Reno, funded by the National Institute of Food and Agriculture, we continue to evaluate the productivity of spineless prickly pear accessions for biomass as well as evaluate the genetic diversity of the prickly pear collection. We are also partnering with scientists at the University of Arizona to evaluate guayule accessions for resistance to root pathogens in a project funded by the Office of National Programs. Descriptor data on the Parthenium collection is being collected by researchers at the University of Arizona and Bridgestone Americas. We continued the process of repropagating the prickly pear collection, using heat treatment as necessary to combat viral disease. Best management practices for management of genetic resources continue to be developed and documented.

Accomplishments
1. Seed stocks of critical crop germplasm from the national gene bank are regenerated. ARS curatorial staff at Parlier, California, regenerate germplasm for other National Plant Germplasm System (NPGS) repositories that are located in harsher climates. These accessions could not be regenerated at their home NPGS sites because of short growing seasons and/or disease pressures. These regenerations are necessary to meet the global distribution, viability, and research needs for these crops. The other NPGS sites send Parlier staff seeds, seedlings, or bulbs prior to the proper time for planting. Seeds, fruit or bulbs are harvested, cleaned, and shipped, and associated data is tracked and shared. Many accessions were regenerated for other repositories in fiscal year 2021, including: Ames, Iowa – 42 sunflower; Aberdeen, Idaho – 1156 small grains (wheat, triticale, rye, and barley); Griffin, Georgia – 15 warm weather squash; Pullman, Washington – 256 garlic, 4 lettuce; Geneva, New York – 15 winter squash.

2. Germplasm of arid land industrial crops is provided freely to researchers around the world. ARSS curatorial staff at Parlier, California, provided seeds and clonal propagules from the arid land industrial crop collections to scientists worldwide. For many of these crops, the National Plant Germplasm System (NPGS) collections are the only available source of seed. This distribution to germplasm users was based on requests originating in the Germplasm Resources Information Network (GRIN). For the period from October 2020 through June 2021, requests from germplasm users totaled 203 accessions in 20 orders. The number of items shipped by crop are as follows: Parthenium (guayule) – 122, Physaria (lesquerella) – 1, Limnanthes (meadowfoam) – 72, and Cucurbita foetidissima (buffalo gourd) – 8. These plant materials are important for research on new drought tolerant crops, many of which could provide domestic alternatives to petroleum products.