Location: Nat'l Clonal Germplasm Rep - Tree Fruit & Nut Crops & Grapes
2023 Annual Report
Objectives
The long-term objective of this project is to preserve the genetic diversity in the collections of the 14 Mediterranean crops for current and future generations. Specifically, during the next five years we will focus on the following objectives.
Objective 1: Efficiently and effectively acquire priority Mediterranean climate-adapted grape, tree fruit, tree nut, and other specialty crop genetic resources; maintain their safety, genetic integrity, health and viability; and distribute them and associated information worldwide.
Objective 2: Develop more effective genetic resource maintenance, evaluation, and
characterization methods and apply them to priority Mediterranean climate-adapted grape, tree fruit, tree nut, and other specialty crop 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 and Crop Vulnerability Statements for Mediterranean climate-adapted grape, tree fruit, tree nut, and other specialty crop genetic resource and information management.
Basis for the objectives: The first two objectives describe the four basic tenets of the mission of the National Clonal Germplasm Repository Davis (NCGR); acquisition, maintenance, characterization and distribution of high quality, healthy, viable, true-to-type genetic resources and the associated evaluation and characterization information in GRIN-Global to the domestic and international scientific and educational communities. The third objective focuses on developing, implementing, and documenting best management practices for the collections and keeping the Crop Vulnerability Statements up-to-date.
Acquisition has focused on crop wild relatives (CWRs) to fill important gaps and much of this germplasm is under quarantine and therefore in the pipeline to the Repository. Maintenance is best accomplished with young, vigorous plants and therefore the Repository is in the middle of a repropagation cycle for the collections. Distribution of germplasm to national and international researchers, breeders, and nurseries is primarily, but not limited to dormant cuttings or scionwood.
Phenotypic evaluation and genetic characterization of the collections focus on
understanding genetic diversity and increasing the visibility and value of the germplasm. Stakeholders are interested in phenotypic data on traits with breeding value. We use Bioversity International descriptors for germplasm evaluation and upload these data to GRIN-Global. Genetic markers discovered at the Repository and by collaborators can help clarify accession identity and assess genetic diversity, structure, and differentiation, and when combined with phenotypes will enhance the value and promote utilization of the germplasm.
Approach
Objective 1
Research Goal 1: Implement best management strategies for the acquisition, maintenance, and distribution of the genetic resources of the NCGR.
Approach: This objective describes three of the four basic tenets of the mission of the National Clonal Germplasm Repository for tree fruits, nut crops and grapes (NCGR) of acquisition, maintenance of the germplasm, and distribution of high quality, healthy, viable, trueto-type genetic resources to the domestic and international scientific and educational communities. The fourth tenet is evaluation and characterization covered in Objective 2. This and other objectives are accomplished by 10 full-time staff, as well as 2-5 part-time student workers.
Objective 2
Research Goal 2: To have better maintained and more thoroughly evaluated and characterized collections and to make the resulting descriptor information more complete and up-to-date in GRIN-Global.
Approach: This objective describes making collection maintenance more effective and is well aligned with the maintenance portion of Objective 1. Evaluation and characterization of the collections increase the visibility and usefulness of this valuable germplasm to the stakeholder community. Phenotypic descriptors have great utilization and help guide breeders and others who must decide which accessions will help advance their program. Therefore, phenotyping is a focus of the NCGR. Genotypic descriptors, such as SSR and SNP markers are also developed for the collections and are useful to the scientific community and for combining with rich phenotypic data to discover QTLs.
Objective 3
Research Goal 3: Regularly document best management practices and update Crop
Vulnerability Statements every 3-4 years.
Approach: This objective describes developing updated and documented best management practices for collection management and evaluation. It also is important to have up-to-date crop vulnerability statements to facilitate communication with stakeholders, identify gaps in the collection, and identify management improvements potentially increasing yield and quality of regenerated propagules. In addition, Crop Vulnerability Statements are used by Office of National Programs when communicating with leadership and lawmakers.
Progress Report
This is the final report for project 2032-21000-024-000D, titled "Managing Genetic Resources and Associated Information of Grape, Tree Fruit, Tree Nut, and Other Specialty Crops Adapted to Mediterranean Climates". It has been replaced by a bridging project 2032-21000-026-000D with the same title, objectives, and milestones which will be in place until the new project completes ad-hoc OSQR review in FY24. For more information, see the bridging project report.
Throughout the duration of this project, activities in support of Objective 1 have been ongoing to implement best management strategies for the acquisition, maintenance, and distribution of genetic resources tree fruits, nut crops, and grapes in Davis, California (the Repository). Field space continues to be limited and the University of California, Davis, which leases land for the research, has not been able to allot more land to the permanent field collections. Although this project is not seeking to greatly expand the collections due to limited field space, gaps in the genetic diversity of the collections are identified with the help of user groups and filled as opportunities arise. Some of the most unique and useful diversity comes in the form of seedling families collected in the wild from Albania, Georgia, Azerbaijan, and other central Asian countries. 32 new seedling families were added over the course of the project, in addition to 45 new clonal accessions from field collections and collaborator donations. During FY 2023 the Repository received 18 new accessions, 12 Prunus, one Vitis davidii, and five additional Vitis hybrids. Additional copies of persimmon and kiwi accessions were repropagated from the historic plant introduction orchard in Chico, California. The maintenance of the field and nursery collections continues to employ the majority of staff time and resources, covering 70 acres of field space and over 10,000 ft2 of covered nursery space. Over the past five years, the almond collection was repropagated and moved to avoid a dangerous soil disease, large trees in the walnut and pistachio collections have been carefully hedged each year to rejuvenate the trees at a more manageable size, and an overgrowth of woody weeds and seedlings have been removed by hand from the grape collection. Securing backups of clonal material in cryopreservation is a challenge for all tree genebanks, and the sweet cherry and plum collections have not been producing suitable dormant buds for this purpose, likely due to warming winter temperatures in California. This year cuttings from the entire Prunus domestica plum collection were sent to ARS researchers in Geneva, New York, for repropagation there and eventual cryopreservation in Fort Collins, Colorado. In FY 2023, the walnut, pistachio, olive and Prunus trees were again mechanically pruned, kiwi vines pruned by hand, and figs pruned and suckered by hand. Detailed health ratings were taken for every tree in the walnut and pistachio collections to direct repropagation efforts, and several trees in immediate need were repropagated into a collaborator field at UC Davis. Sprays were employed for insect pests and diseases caused by microbes and nutrient deficiencies. Weed control (i.e., herbicides) and manual removal activities continued to require significant effort from the staff.
Distribution of plant material in the form of dormant and green cuttings, pollen, flowers, fruit, and leaves is the second-highest service priority, and continued demand for the material is documentation of the value to researchers globally. Over the life of this project (3/1/2018 – 2/28/2023), staff shipped 1,203 orders (Domestic requesters: 1,154 total- 48 Federal, 318 State and University, 279 Commercial, 62 Non-profit, 447 individuals. International: 49 total). The 1,203 orders consisted of 21,511 inventories that were shipped during that time period. 12,001 inventories were collected as bud sticks/cutting with a total of 56,144 individual sticks. 1,156 inventories were collected as fruit with a total of 13,837 fruit. 6,357 inventories were collected for packets of leaves. 78 inventories were shipped as plants with a total of 320 plants. 299 inventories were collected as vials of pollen. 318 inventories were collected as packets of seed. 19 inventories were collected as flowers. 1,143 inventories were shipped as DNA with a total of 2,278 individual samples. 140 inventories were collected as in-vitro shoot tips. The demand for individual accessions (inventories) by crop reflects the overall size and diversity of each collection: Grape (6,740), Prunus (4,499), Walnut (2,683), Fig (2,245), Pomegranate (1,470), Pistachio (1,220), Olive (824), Persimmon (600), and Kiwi (508).
In support of Objective 2, research continued on the evaluation of the collections and posting of those results in the Germplasm Resources Information Network (GRIN) Global database so that stakeholders can better understand and use the collections in their research. Knowledge of the amount and patterns of distribution of genetic diversity within and among species' gene pools is of considerable value for effective conservation, enrichment, management, and utilization of genetic resources. Over the course of this project, genetic characterization studies on each of the collections were published that shed light on the relationships between the cultivated crops and their wild relatives, and important sources of disease resistance. Thousands of individual observations, including photos, were uploaded to GRIN-Global to improve the utilization of the collections. In FY 23, photos were taken of mature fruit from approximately 500 walnut trees and staff participated in a meeting of the walnut crop germplasm committee. A large backlog of Prunus observations (7,183) and images (1,856) were uploaded to GRIN-Global. Additionally, pomegranate fruit was collected and shipped to collaborators for a postharvest disease evaluation, and juice from over 100 wine and table grape varieties was collected for analysis by ARS researchers in Geneva, New York.
In support of Objective 3, staff at the Repository worked closely with other genebanks, Crop Germplasm Committees, university collaborators, farm advisors and pest control advisors to improve and document best management practices for the maintenance of the germplasm collections. Over the life of the project, major improvements to the field and nursery operations include the introduction of mechanical hedgers and chippers for pruning debris, improved nutrient management and pest control sprays, installation and upgrades to automatic watering systems, and the training and certification of new field and nursery management staff. Before retiring in December 2023, the Prunus crop manager compiled detailed best management practices documentation for all Prunus crops. Additionally in FY 23, protocols for rooting cuttings of mulberry and kiwi were documented and shared with collaborators, and irrigation timers and emitters were upgraded in the nursery.
Accomplishments
1. Unique, high quality plant material distributed to support global research and crop development. Genetic resources were freely distributed to cooperators worldwide, especially geneticists and breeders who develop new cultivars to address the needs of growers and consumers. Most germplasm requests were shipped in late winter/early spring as three to five cuttings per accession. Leaves, pollen, and fruit were also sent as requested. ARS scientists and staff in Davis, California, shipped 21,511 items in 1,203 orders to stakeholders (49 international and 1,154 domestic) for research and education activities that require genetic diversity or genetic standards.
