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

Location: Office of The Director

2018 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 project 2034-21000-012-00D and continues research from expired project 2034-21000-011-00D, "Management of Arid Land Plant Genetic Resources and Associated Information." Progress toward Objective 1 was in two main areas: regenerations for other sites and serving as the backup site for the National Hazelnut collection. The National Arid Land Plant Genetic Repository (NALPGRU) served other National Plant Germplasm System (NPGS) sites by regenerating annual accessions that cannot produce seed at their home sites because they do not have a long enough growing season. 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), harvest, and shipment of increased seed back to the home site. This includes frequent coordination with the curators of these crops and photo updates, some of which they use to add to the available descriptors on the Germplasm Resources Information Network (GRIN-Global). Regenerations planted during FY18 for other NPGS sites included 255 garlic, 8 lettuce, 40 faba bean, 618 small grains, 5 pepper, 50 cowpeas, 20 watermelon, 9 squash, 37 sunflower, and 3 cumin. The hazelnut backup collection from Corvallis, Oregon, was removed and partially replaced with newly propagated plants. These plants are established and growing. Eventually, there will be one copy of each accession backed up at the Repository. NALPGRU priority crops are a combination of clonal accessions (prickly pear, jojoba) and seed propagated accessions (meadowfoam, bladderpod, guayule, buffalo gourd). Seed stocks in the meadowfoam, bladderpod, guayule, and buffalo gourd collections, are being regenerated, with emphasis on accessions with low germination or low seed supply. To date, because it is still the growing season, efforts are being made to improve genetic resource maintenance and improve plant growth and seed production. Evaluation funding through the Office of National Programs and the New Crops Crop Germplasm Committee (CGC) is being used to develop a method for screening rubber content of guayule plants in vitro. The NALPGRU filled eight requests for germplasm from the start of this project through July 2018, with a total of 157 accessions shipped. No accessions were added to the collection; however, funding was approved through the New Crops CGC and the Plant Exploration Office for a collection trip to southwest Texas. Best management practices continue to be developed. Work is underway with the New Crops CGC to revise the crop vulnerability statements, and descriptors for the Parthenium collection will be discussed at the next annual meeting.

Accomplishments
1. Seeds and clonal propagules for drought tolerant crops are distributed worldwide from the national collections. Researchers at the repository in Parlier, California, provided seeds and clonal propagules from the national collections to scientists worldwide. This distribution to germplasm users was based on requests originating in the Germplasm Resources Information Network (GRIN). For the period from March 2018 through July 2018, requests from germplasm users totaled 157 accessions in eight orders. The total accessions shipped by crop are as follows: Opuntia (prickly pear) – 31, Parthenium (guayule) – 123, Agave – 2, and Cucurbita foetidissima (buffalo gourd) – 1. These plant materials are important for research on drought tolerant crops.

2. Germplasm regeneration performed in mild climate for National Plant Germplasm System gene banks. Researchers at the repository in Parlier, California, regenerated germplasm for other repositories that are located in harsher climates. Many accessions were regenerated for other repositories in FY18, including: Ames, Iowa – 3 cumin, 37 sunflower; Aberdeen, Idaho – 618 cereals (wheat, triticale and barley); Griffin, Georgia –5 peppers, 20 watermelon, 50 cowpea, 50 eggplant, 2 miscellaneous cucurbits; Pullman, Washington – 255 garlic, 1 Hedysarum (French honeysuckle), 40 fava bean, 8 lettuce; and Geneva, New York – 6 brassicas, 9 squash. These accessions could not be regenerated at their repository sites because of the short growing seasons and harsh climate. The other repositories sent the seeds, seedlings, potatoes or garlic bulbs prior to the proper time for planting at the Parlier repository. Seeds, potatoes or bulbs were harvested, cleaned, and shipped. These regenerations are necessary to meet the distribution, viability, and research needs for these crops.

3. Critical seed regenerations performed for arid lands crops. Regeneration of germplasm collections is an important activity for gene banks because seeds from accessions are distributed, losing viability over time, and therefore must be replaced. However, seed regeneration is costly and presents the risk of contaminating the accession through cross-pollination or creating a genetic “bottleneck”. Therefore, it is important to carefully monitor seed inventory and viability to ensure that only critical accessions are regenerated each year. Further, every effort must be taken to plant large populations of each accession and prevent cross-pollination. Following these guidelines, ARS researchers in Parlier, California, regenerated and harvested seed for the following number of accessions: 1 buffalo gourd (Cucurbita foetidissima), 5 bladderpod (Physaria, Paysonia). In addition, eight accessions of the perennial crop Parthenium (guayule) were caged. Flies were introduced for pollination and fresh seed harvested for storage.