Location: Small Grains and Potato Germplasm Research
2022 Annual Report
Objectives
The long-term objective of this project is to maintain and enhance NSGC as a worldwide resource of small grains germplasm for the research community. Specifically, during the next five years we will focus on the following objectives. Objective 1. Efficiently and effectively acquire genetic resources of small grains and their wild relatives; maintain their safety, genetic integrity, health and viability; and distribute them and associated information worldwide. 1A. Acquire crop wild relatives of wheat, barley, rice, and oat that are under-represented by taxonomy or geography and other threatened small grains germplasm. 1B. Maintain and back-up NSGC accessions. 1C. Regenerate NSGC accessions on a continuing basis with priorities determined by seed inventory and viability. 1D. Distribute on request NSGC accessions and information that meet the specific needs of researchers worldwide. Objective 2. Develop more effective genetic resource maintenance, evaluation, and characterization methods and apply them to priority small grains genetic resources; screen for host-plant resistance to virulent diseases, such as the Ug99 wheat rust strain. Record and disseminate evaluation and characterization data via GRIN-Global and other data sources. 2A. Assess putative duplicate accessions for barley and wheat. 2B. Characterize resistance to bunt and stem rust in NSGC wheat accessions. 2C. Collect remaining priority characterization data and record in GRIN-Global. Objective 3. With other NPGS genebanks and Crop Germplasm Committees, develop, update, document, and implement best management practices and Crop Vulnerability Statements for small grains genetic resource and information management. 3A. Review and update NSGC standard operating procedures for all aspects of curation and implement best management practices in coordination with other NPGS sites. 3B. Engage with small grains Crop Germplasm Committees (CGCs) to update crop vulnerability statements and identify germplasm acquisition and evaluation priorities of interest to the respective committees.
Approach
Objective 1. Acquisition priorities include the wild relatives of Triticum, Hordeum, Avena, and Oryza to fill species and ecogeographic gaps in the crop collections. Highest priority will be primary genepool relatives of these genera, identified in collaboration with the Crop Germplasm Committees (CGCs). These gaps will be addressed by collection expeditions and exchanges with other genebanks. Seed of NSGC accessions are held in medium-term storage under controlled temperature (5-6o C) and relative humidity (25%). Detailed inventory records are maintained in GRIN-Global. Seed will be provided to NLGRP for safety back up. Accessions in need of regeneration will be grown at several locations as follows: Aberdeen, Idaho in fields of the University of Idaho Research and Extension Center and in USDA-ARS greenhouses; Parlier, California at the USDA-ARS National Arid Land Plant Genetic Resource Unit; and Stuttgart, Arkansas at the USDA-ARS Dale Bumpers National Rice Research Center. Accessions will be scheduled for regeneration based on a priority matrix. Viability tests are scheduled every five years. Standard procedures for GRIN-Global Order Processing will be followed. Distributions outside of the U.S. will follow phytosanitary requirements of the recipient country, including import permits, phytosanitary certificates, and additional declarations. USDA-APHIS will be consulted regularly for the latest information on seed export. Seed shipments to other countries will be coordinated with the National Germplasm Resources Laboratory (NGRL), Plant Exchange Office. Noxious weeds will be distributed under a USDA-APHIS permit. Accessions that fall under the International Treaty for Plant Genetic Resources for Food and Agriculture will follow appropriate guidelines and will include agreement to the Standard Material Transfer Agreement by the recipient. Objective 2. Molecular markers and morphological traits will be used to develop a method to assess variation within and between NSGC wheat and barley accessions. After establishing the method, the barley and wheat collections will be sampled to measure the degree of duplication within each. Using the data from this study, verified duplicate accessions may be combined. Using genome wide association and bi-parental mapping approaches, genes for bunt and stem rust resistance will be sought within the NSGC wheat collection. Markers associated with novel resistance to the Ug99 stem rust group of races will be validated in various genetic backgrounds. Remaining priority characterization data will be collected and recorded in GRIN-Global. Objective 3. SOPs for all aspects related to acquisition, maintenance, regeneration, characterization, evaluation, and distribution will be reviewed, updated, and compiled into a complete NSGC operations manual of procedures. Through meetings and discussions with the small grains CGCs the priorities of these research communities will be identified and reflected in crop vulnerability statements and NSGC descriptors. Ongoing dialogue with the CGCs will be maintained.
Progress Report
In support of Objective 1, ARS researchers at Aberdeen, Idaho, currently hold 149,918 accessions of small grains, which include wheat, barley, oat, rye, triticale, rice, and related wild species in the National Small Grains Collection (NSGC). Seed distributions to scientists totaled 25,437 accession samples in 480 separate requests, and scientists from foreign countries continue to make up one-third of these requests. More than 20,000 viability tests were completed. Regeneration grow-outs were completed for more than 7,000 accessions. Research continued in acquiring genetic resources of small grains and their wild relatives, while maintaining safety, genetic integrity, health, and viability. Almost 2,000 accessions were acquired in the past year.
In support of Objective 2, more than 7,800 spike and panicle samples were collected from NSGC field regeneration nurseries, and voucher images were created and uploaded to GRIN-Global. Characterization data for priority descriptors were recorded from field nurseries and voucher images and uploaded to GRIN-Global.
In support of Objective 3, Standard Operating Procedures (SOPs) for the NSGC were updated for GRIN-Global order processing and viability testing to reflect new seed handling procedures verified by bar-code-matching at every stage.
Researchers at Aberdeen, Idaho, Lincoln, Nebraska, Raleigh, North Carolina, and St. Paul, Minnesota, organized three U.S. wheat and barley breeding nurseries for testing in East Africa against Ug99 variants of stem rust in cooperation with the International Center for Maize and Wheat Improvement (CIMMYT) in Mexico City, Mexico, the Kenya Agriculture and Livestock Research Organization (KALRO) in Nairobi, Kenya, and the Ethiopian Institute of Agricultural Research (EIAR). In three separate nurseries, 1,451 and 2,794 entries were sent to Njoro, Kenya, and 1,451 entries were sent to Addis Ababa, Ethiopia.
Accomplishments
1. Wheat characterization data available to researchers worldwide. The ARS National Small Grains Collection (NSGC) in Aberdeen, Idaho, maintains a collection of more than 57,000 wheat accessions from 112 countries. This diverse wheat collection is available to researchers for breeding, research, and education for the benefit of U.S. and world agriculture. Characterization data including growth habit, awn color, awn type, glume color, and spike density are important components in describing the diversity available in these accessions. Gaps in this data can limit the usefulness of the wheat collection. During the past year, ARS researchers made significant reductions in these gaps by the addition of more than 13,000 data records to GRIN-Global.
2. Acquired a spring wheat nested association mapping population. The ARS National Small Grains Collection (NSGC) in Aberdeen, Idaho, maintains a collection of wheat germplasm that is often underutilized by breeders due to the time and resources required to study and identify promising unadapted accessions. NSGC acquired a spring wheat multi-parent introgression population (SWMIP) or nested association mapping population consisting of 1,987 accessions, developed by University of Minnesota researchers at St. Paul, Minnesota. This SWMIP was developed by crossing selected wheat accessions from the NSGC wheat core subset to an adapted cultivar to generate half-sib recombinant inbred line (RILs) populations. These RILs can utilize standard methods for studying quantitative trait loci, which then allows breeders to exploit exotic germplasm for wheat improvement more easily.
Review Publications
Gordon, T.C., Jin, Y., Tinker, N.A., Bekele, W.A., Gale, S.W., Bockelman, H.E., Bonman, J.M. 2022. Comparative sequencing and SNP marker validation for oat stem rust resistance gene Pg6 in a diverse collection of Avena accessions. Theoretical and Applied Genetics. 135(4):1307-1318. https://doi.org/10.1007/s00122-022-04032-z.
Gordon, T.C., Jin, Y., Gale, S.W., Rouse, M.N., Stoxen, S.M., Wanyera, R., Macharia, G., Randhawa, M., Bhavani, S., Brown Guedira, G.L., Marshall, D.S., Babiker, E.M., Bockelman, H.E., Bonman, J.M. 2021. Identification of winter habit bread wheat landraces in the national small grains collection with resistance to emerging stem rust pathogen variants. Plant Disease. 105(12):3998-4005. https://doi.org/10.1094/PDIS-04-21-0743-RE.
