Location: Floral and Nursery Plants Research
2019 Annual Report
Objectives
Objective 1: Efficiently and effectively acquire priority temperate-adapted woody landscape plant genetic resources; maintain their safety, genetic integrity, health and viability; and distribute them and associated information worldwide. [NP301, C2, PS2A; C1, PS1B]
Sub-objective 1.a. Acquire samples and associated information of select taxa via exploration, contract collecting, and exchange. Targeted taxa include: Cladrastis kentukea, Viburnum species, Quercus species, Acer saccharum subsp. leucoderme and floridanum, Lindera benzoin, and Hamamelis ovalis.
Sub-objective 1.b. Maintain and backup plant germplasm, including conduct germination tests on stored seed to determine viability of older germplasm; update seed collection and GRIN-Global database to reflect inventory; prioritize and regenerate or re-collect vulnerable accessions.
Sub-objective 1.c. Distribute accessions and information that meet the specific needs of researchers, breeders, conservationists, nursery professionals, and other stakeholders.
Objective 2: Develop more effective genetic resource maintenance, evaluation, and characterization methods and apply them to priority temperate-adapted woody landscape plant genetic resources. Record and disseminate evaluation and characterization data via GRIN-Global and other data sources. [NP301, C2, PS2A]
Sub-objective 2.a. Develop and apply molecular markers for analysis of genetic diversity, taxonomic identity, and/or population structure for Tsuga chinensis and other priority taxa.
Sub-objective 2.b. In collaboration with nurseries, botanic gardens, and university cooperators, evaluate horticultural merit of accessions collected under sub-objective 1.a and those already included in our living collections; disseminate information and superior germplasm or selections.
Objective 3: With other NPGS genebanks, Crop Germplasm Committees, and customers/stakeholders, develop, update, document, and implement best management practices and a Crop Vulnerability Statement for temperate-adapted woody landscape plant genetic resource and information management. [NP301, C2, PS2A]
Approach
High-quality germplasm identified from in situ populations or ex situ collections will be acquired in the most efficient manner. For many acquisitions, this will be through germplasm requests, exchanges, and local collecting. Domestic collections for the eight taxa identified as priorities (Cladrastis kentukea, Viburnum, Quercus, Hamamilis ovalis, Lindera benzoin, Fagus grandifolia, Sassafras albidum, and Acer saccharum subsp. leucoderme and floridanum) will focus primarily on eastern North America. Our approach will be to collaborate with local experts including other scientists, botanists, and collectors. The number of species targeted and collection goals in each specific effort will depend in part on the extent of the collaborators’ involvement and ease of access to sites.
We will use a contracted service for seed viability testing. Seed that is more than ten years old will be prioritized for viability testing based on the quality of passport data, its conservation status, and the number of requests received for that taxon. Seed that has no viability will be deaccessioned or inactivated following the NPGS Inactivation Guidelines developed by the PGOC. Seed will also be regenerated in-house or recollected. Seed from regenerated or collected accessions will be sent to the NCGRP in Ft. Collins for long-term backup.
We will follow our established protocols for meeting distribution requests that come through GRIN-Global for accessions already in the system. We will also distribute seeds of newly acquired taxa to collaborators for conservation or evaluation. Basic passport data (taxonomic information, collection locations, dates) are maintained in GRIN-Global for each accession. We will supplement these data with evaluation and descriptive information and images from collaborative evaluation projects which will add value to the germplasm.
To evaluate germplasm, we will use SSR markers to determine relationships among and diversity within accessions of Tsuga chinensis and Lindera benzoin. We will also evaluate the horticultural merit of germplasm accessions through collaborative agreements with several cooperators. Plants will be evaluated for various horticultural and production traits. Data will be collected after three years of field trials, and for two to five years subsequently, depending on the genus.
In order to update and implement best management practices and a Crop Vulnerability Statement for germplasm, we will maintain and establish collaborations with WLPGR users and other stakeholders to ensure that the collections are relevant, well-curated, accessible, and effectively utilized. We will work with the Crop Germplasm Committee to develop a list of targeted genera or species which are most vulnerable or otherwise in need of conservation. We will also update our internal “Operations Manual”, which provides specific guidance on identification, collection, maintenance, distribution, and evaluation of germplasm specific to the WLPGR, and also addresses database management, invasiveness, staffing, equipment and facilities, the WLPCGC, and safeguarding germplasm.
Progress Report
Substantial progress was made on all project objectives. Under Objective 1, we conducted a scouting and leaf collection trip for Cladrastis kentukea to the states of South Carolina, North Carolina, and Georgia to document the current collecting conditions to help us plan for seed collecting in the fall of 2019. We also worked with the ARS Plant Exchange Office to collaborate with a local botanist in Kentucky to scout for Cladrastis populations for fall 2019 collecting, and we continued to collaborate with the ARS PI stationed in Ames, IA, from whom we received leaf samples from 8 populations in Oklahoma and Missouri. In the fall of 2018, we collected Viburnum species in Vermont, New Hampshire and Pennsylvania in our ongoing effort to conserve species that are affected by Viburnum Leaf Beetle. An earlier-than-expected fruiting season and heavy seed predation limited our collection success, although we did collect 12 accessions representing four species. Plans are in place for a return trip in 2019. We also entered a collaborative agreement with the Mid Atlantic Regional Seed Bank to collect four viburnum species from across their range in New York State, and have collaborators in Maine and Illinois to collect native Viburnum in those areas.
In the fall of 2018 we scouted in central and western Maryland to look for five targeted Quercus species native to the mid-Atlantic region. Due to poor seed set, we were not able to collect seed. Two collection trips were made in the fall of 2018 to collect Acer saccarhum ssp. floridanum and ssp. leucoderme from their northern range. Five accessions of floridanum and three accessions of leucoderme were collected. This seed has been sown, and resulting plants will be evaluated for their adaptability to northern climates for possible landscape potential. We continued our collaboration with the American Public Garden Association (APGA) on Sassafras conservation in response to the threat of Laurel Wilt on this species. Collaborating public gardens sent leaf material from across the range of Sassafras, which will be used to assess genetic diversity of native populations to guide conservation targets. In collaboration with the ARS Plant Exchange Office, we have contract collectors in the Republic of Georgia targeting 31 diverse plant taxa, and in Kentucky targeting six species of Amelanchier. To determine viability of seed being considered for long-term storage at the National Laboratory for Genetic Resource Preservation (NCGRP) in Fort Collins, we sent 133 seed accessions to the U.S. Forest Service Seed Lab for viability testing. Results indicated only 21 accessions had viability rates high enough for NCGRP standard protocols. Plans are in place to ship the 21 accessions to Fort Collins.
We distributed 445 accessions to 140 requestors including 12 international research institutes, 37 public gardens, 30 commercial organizations, 30 colleges and universities, 18 private individuals, and five USDA/ARS locations. 514 new accessions of woody landscape plants were added to the National Arboretum inventory with 243 of those accessions originating from the WLPGR.
Under Objective 2, we completed a study to examine the molecular genetic diversity of Tsuga chinensis in the U.S. We also began an assessment of the genetic diversity of native sassafras populations from across the U.S. by collecting leaf samples from approximately 150 trees from at least 20 sites. We completed the release notice for a new cultivar of Styrax japonica ‘Burgundy Moon’.
Under Objective 3, our 24-year collaboration with the American Public Gardens Association remains strong and productive, with 129 existing national collections. The National Arboretum hosted the APGA’s Plant Collections Network (PCN) meeting in June 2019 with discussions concerning disaster planning and the Arboretum’s future PCN application of Lagerstroemia. The USNA Acer collection was approved as a National Accredited Collection within the Plant Collections Network. In collaboration with APGA and the Plant Introduction Station in Ames, Iowa, we presented a poster at the APGA Annual Conference titled “Expanding Seed Collecting Efforts of Plant Expeditions for Long-Term Conservation” to engage the public garden community to improve seed collection methods to promote long-term seed viability in gene banks. We attended the Plant Collections Collaborative meeting in Charlotte, North Carolina to discuss germplasm collection and conservation efforts including improving seed collection standards. We have also completed a revision of the Woody Landscape Plants Germplasm Repository (WLPGR) Operations Manual, which is currently undergoing final internal review.
Accomplishments
1. Release of a new Styrax japonicus ‘Burgundy Moon’. The introduction of new woody ornamental plants is one of the driving forces behind the sustained growth of the ornamental horticulture industry. Researchers from the Woody Landscape Plant Germplasm Repository in Beltsville, Maryland, released a new cultivar of Japanese snowbell called ‘Burgundy Moon’. This cultivar was selected for its unusual burgundy-colored calyx and stem that caps abundant, creamy-white fragrant flowers. It is well-suited for use as a specimen plant near a patio, walkway, or entrance where its fragrant flowers can be enjoyed, or under utility lines because of its slow growth. ‘Burgundy Moon’ helps to diversify the palette of landscape plants available to growers, landscapers, and the gardening public.
