Location: Office of The Director
2025 Annual Report
Objectives
Objective 1: Conduct research to develop genetic resource regeneration, maintenance, evaluation, or characterization methods and, in alignment with the overall NPGS Plan, apply them to priority arid-adapted plant genetic resources to avoid backlogs in genetic resource and information management.
Sub-objective 1.A: Based on the data collected in the NPGS Plan, develop a long term PGR management strategy for addressing current needs and avoiding future backlogs in the management of the NALPGRU arid lands emerging crop collection.
Sub-objective 1.B: Investigate and develop new PGR management methods for NALPGRU crops. Collect evaluation and characterization data and make them available through GRIN-Global and other data sources.
Objective 2: Conduct research to develop regeneration methods and, in alignment with the overall NPGS Plan, apply them to priority plant genetic resources that require long seasons and/or arid climates so as to avoid backlogs in genetic resource regeneration.
Objective 3: Acquire, distribute, and maintain the safety, genetic integrity, health, and viability of priority arid-adapted plant genetic resources and associated descriptive information.
Sub-objective 3.A: Strategically increase genetic diversity of the Parthenium (guayule) and Opuntia collections by addressing stakeholder-identified gaps through plant exploration and exchange.
Sub-objective 3.B: Continue to maintain the highest possible availability, quality, and security of seed and clonal germplasm in diverse collections of arid-adapted new crops.
Sub-objective 3.C: Distribute high-quality germplasm in the form of seeds, cuttings, and plant tissue to stakeholders worldwide.
Approach
1.A: We will consult with partners to create a PGR management strategy based on the NPGS Plan. This strategy will include prioritized lists of backlogs to address by crop as well as plans for further reducing and preventing backlogs in the future.
1.B: We will identify core diversity and production subsets in the guayule collection. We will investigate seed quality in guayule regeneration by comparing caged and open-pollinated plants. If caging does not impact quality, we will follow with a comparison of caged plots with and without pollinators. We will phenotype the Opuntia collection, prioritizing the traits most useful to requestors (fruit soluble solids content, fruit size, seediness, spine length, etc). Additionally, we will upload existing photos to GRIN-Global.
2: Regeneration and back-up of accessions from other NPGS sites will be coordinated with the NPGS curators responsible for the crops. This service regeneration objective is distinct from regenerations for crops maintained by NALPGRU (3.B). Regeneration involves growing plants in the field, tracking inventory, controlling/facilitating pollination, monitoring for pests and diseases, collecting descriptor information and photos, harvesting and cleaning seed, and returning increased seed to the priority site along with data for upload to GRIN-Global.
3.A: We will coordinate with the New Crops CGC to plan exploration trips and apply for funding through the Plant Exchange Office (PEO). We will add diversity in Parthenium species through the Seeds of Success program and pursue options of in situ conservation on public lands in Texas through the PEO. We will conduct a gap analysis of the Opuntia collection using recently completed phenotypic and genotypic diversity analyses to determine future collection priorities.
3.B: NALPGRU collections are maintained as clonal and/or seed accessions, depending on the needs of the crop. Seed must be periodically regenerated to maintain viability and distribution. Each year seed inventories will be analyzed to identify accessions with the highest regeneration priority following the PGR management strategy developed in Sub-objective 1.A. Also following the PGR management strategy, seed of the best available quality will be transferred for backup to NLGRP in Ft. Collins, CO. The guayule field plots will be replanted from original seed in 4 stages. The Opuntia field block also requires re-propagation, and will be installed over 2 years. Some existing Opuntia has symptoms of ‘cladode-swelling disease’. The disease can be eradicated by regenerating the plant from asymptomatic tissue or cleaned up using cycles of thermotherapy. This program began in the last planning cycle, and we will continue to produce asymptomatic material for planting in the new perennial block.
3.C: NALPGRU receives requests for germplasm through GRIN-Global and reviews for legitimacy. Domestic requests are shipped directly after meeting phytosanitary requirements. International requests are sent to NGRL in Beltsville for coordination with APHIS and shipment to the destination.
Progress Report
This report documents FY 2025 progress for project 2034-21000-013-000D, “Management of Germplasm and Associated Descriptive Data for Crops Adapted to Arid Lands and Regeneration of Germplasm”, which began in March 2023.
This project supports the mission of the National Plant Germplasm System (NPGS) by maintaining, evaluating, and distributing accessions of arid-adapted and industrial crops and providing a long-season regeneration site for accessions with special climatic requirements from other NPGS sites.
The 2025 fiscal year initiated with substantial progress towards multiple management and research goals established to improve the availability, regeneration efficiency, safety, and characterization of priority arid-adapted plant genetic resources and crops regenerated by as a service for other NPGS sites. These efforts were led by a postdoctoral research associate who completed a second year serving as the interim curator and research agronomist and supported during FY 2025 initially by two permanent full-time technicians, a seasonal technician, and seasonal contract labor during peak efforts.
This project maintains and distributes a complex collection of arid-adapted and industrial plant genetic resources with over 1500 active accessions from more than 200 species. Depending on their biology and stakeholder needs, these are maintained as clonal field plants, greenhouse plants, or as seed collections. The specialized expertise required to maintain this collection was provided by both permanent and temporary staff, each with years of practical experience.
Objective 1 is focused on research and development activities to improve the genebank management strategies to efficiently improve the long-term safety, availability, and utility of the crops conserved and distributed.
The second year of a two-year experiment to investigate the effect of providing supplemental insect pollinators to caged guayule regenerations was established and is currently ongoing. Most guayule accessions are facultative apomicts that do not explicitly require pollination to produce seed. However, many of the guayule seed regenerations produce a high proportion of non-viable and unfilled achenes that reduce the efficient management of this collection and the utility of distributions to stakeholders. Historical literature suggests that providing supplemental pollinators improves the production of high-quality viable seeds, and this research seeks to test that hypothesis within diverse accessions. In addition to the establishment of the second year of this study, seed lots from the first year were cleaned and processed for seed quality and viability testing. Guayule seed cleaning is an intensely laborious process, requiring several hours per sample and the loss of technical staff has delayed this project.
Seed of seven guayule accessions selected in conjunction with stakeholders to serve as a diversity core collection were planted in a greenhouse to establish expanded field plots for seed production and observation. The first attempt was made with original seed lots to ensure optimal genetic diversity and avoid any potential genetic bottlenecks. However, the original seed lots failed to germinate, and the planting will be attempted again with newer seed lots.
A complete, multi-parameter inventory was taken of the Opuntia (prickly pear cactus) collection to improve the ability to quickly quantify the availability and health status of each individual accession. The Opuntia collection exists across multiple locations and formats, including a clonal field collection and several greenhouse sub-collections. Each accession has individual clones throughout these locations with varying levels of health and condition that prior to this effort were not organized into a single digitally searchable inventory. This effort was part of a broader project to prepare Opuntia propagative materials to establish a new Opuntia clonal field collection to replace the current collection that is rapidly declining in health due to age. Besides facilitating this new field collection, this inventory will also serve as the starting point for the establishment of a new Opuntia and greenhouse inventory management system integrated with GRIN-Global and other information management systems to improve the ability of staff to rapidly identify, monitor, and characterize the complete collection. Finally, a research grant proposal was submitted with collaborators at the University of Nevada Reno and others to characterize the Opuntia collection for multiple physiological and agronomic parameters across multi-environment trials. The project was funded by the Department of Energy (DOE) and will run for five years.
Objective 2 focuses on providing service regenerations and backups to other NPGS sites and research to improve these efforts. This year, ARS genebank staff in Parlier, California, regenerated 783 small grains accessions; 270 garlic accessions; and 34 sunflower accessions. Additionally, an experimental regeneration of 13 Phaseolus polystachios accessions was established. Further regenerations were paused due to reductions in staffing at ARS in Parlier, California.
The second field season of a replicated field trial comparing the efficiency of different insect pollinators in Cucurbit regenerations in collaboration with ARS genebank staff in Geneva, New York, was also paused due to reductions in staffing at ARS in Parlier, California. Earlier this year, fruits from the first field season were harvested, phenotyped, and seed extracted for further analyses.
Objective 3 focuses on the acquisition, safety, maintenance, and distribution of high-quality plant genetic resources and information for arid-adapted and industrial crops.
New clonal field plots of 97 Opuntia accessions were planted in May 2025 as part of a multi-year process to replace the current Opuntia clonal field collection to ensure the safety of these accessions and improve their availability. Plants in the current clonal field collection are 20 to 30 years old, and many are at a severe risk of loss due to age-related decline and the accumulation of pests and disease. Included within the accessions planted were four accessions that were no longer available but were able to be re-established using plant material from collaborators at the University of Nevada, Reno.
Planting these accessions required over one year of preparation, and the planting of an additional 123 accessions will occur over the next two years. Part of the preparatory process is a multi-generation heat treatment protocol to address Cladode Swelling Disease, a disease likely present in the existing field collection that limits the availability of quality propagative cladodes. Cladodes are sampled from symptomatic plants, treated under 60 degrees C for 60 minutes, and then planted in the greenhouse. Once a new mature cladode grows from this planting, the process is repeated for a second treatment generation, and then a third, to provide symptom-free planting materials withing two to three years from the original sampling date. Most Opuntia accessions are currently moving through this protocol; however, in late FY2025 these efforts were paused due to reductions in staffing and a need for remaining staff to reorganize these and other efforts with reduced resources.
Six new Opuntia genotypes were donated in April 2025 from the Luther Burbank Home and Gardens in Santa Rosa, California, and planted in both clonal field plots and greenhouse plants. Luther Burbank was a prolific Opuntia breeder who developed many well-known spineless Opuntia varieties for fruit and fodder production. The existing collection has some spineless varieties that might trace back to these historic varieties, but the addition of known genotypes with a clear provenance from the original Burbank plantings will provide a valuable resource for both stakeholders and geneticists.
Eight new guayule genotypes that were established into field plots in 2024 completed their first successful establishment year and are expected to enter seed production for accessioning and distribution next year. A planned exploration of newly identified guayule populations in Arizona for seed collection and possible inclusion in the public collection was cancelled for FY2025 due to reductions in staffing.
From July 2024, to May 2025 ARS genebank staff in Parlier, California, shipped 25 germplasm request orders containing 293 items to both domestic and international cooperators. In May 2025, the curatorial team decided to temporarily pause distributions from Parlier, California, due to reduced staffing and a need to reorganize procedures to operate with reduced resources without compromising the safety of the collections.
Accomplishments