Progress 10/01/23 to 09/30/24
Outputs
PROGRESS REPORT Objectives (from AD-416): 1: Conduct research to develop genetic resource maintenance, evaluation, or characterization methods and, in alignment with the overall National Plant Germplasm System (NPGS) Plan, then apply them to priority tropical and subtropical ornamental genetic resources to avoid backlogs in plant genetic resource and information management. 2: Acquire, distribute, and maintain the safety, genetic integrity, health, and viability of priority tropical and subtropical ornamental genetic resources and associated descriptive information. 3: Broaden the diversity available for genetic improvement of subtropical and tropical ornamental crops by selecting superior genotypes from cultivars, landraces, and wild relatives that could be directly cultivated, or form the bases for novel breeding populations. 3A: Characterization and evaluation of Fiji Dwarf coconuts 3B: Developing molecular resources for Florida native palms and increasing the palm diversity in the NPGS. Approach (from AD-416): The long-term objectives of this project are to ensure a secure and diverse stream of new genetic variation and enhanced germplasm for the subtropical/tropical ornamental horticulture industry as well as generate and consolidate detailed information about the intrinsic genetic variability, systematic relationships, and ornamental merit of genetic resources via genetic characterization, systematic studies, and field evaluation. These objectives are non-hypothesis-driven research. The objectives form an integrated program of subtropical/tropical ornamental germplasm characterization, enhancement, and improved management practices. The program efficiently and effectively maintains the safety, genetic integrity, health, and viability of subtropical and tropical ornamental genetic resources. Collections of priority tropical and subtropical ornamental taxa and associated information will be strategically expanded and improved, distributing them worldwide to customers and stakeholders, emphasizing priority genera identified by appropriate Crop Germplasm Committees. Guided by new knowledge of the genetic relationships and valuable ornamental traits of poorly-known plants, superior new cultivars, and genetically enhanced populations and/or selections of priority subtropical and tropical ornamental crops will be developed. Application of high throughput genomic technologies involving next-generation sequencing (NGS) and phenomic approaches will be carried out to improve the selection of cultivars and explore native wild germplasm that would eventually enable breeders, biologists, and other stakeholders to use these genetic resources more effectively and efficiently. Objective 1: USDA-ARS-Subtropical Horticulture Research Station (SHRS) maintains an extensive and distinct collection of tropical and subtropical ornamental germplasm sourced from various global climates, spanning over 220 acres. As a service-oriented initiative, ornamental scientists at the USDA-ARS-SHRS in Miami, Florida completed a comprehensive field inventory of over 2,000 ornamental National Plant Genetics Resource germplasms. This meticulous process included precise geo-referencing of each germplasm to accurately track its location and status. Additionally, the team cleared ~1500 faded and displaced old germplasm paper quoted aluminum tags, implementing a plan to replace them with durable, interactive, UV-resistant QR-coded digital metal tags for all tropical and subtropical ornamental germplasm. The research team created a database of more than 1500 ornamental plants with durable QR- coded metal tags to ensure their identification. These tags are fully compatible with the USDA-GRIN global network and contain germplasm passport information that can be readily accessed in the field. The inventory data was analyzed to identify species diversity at SHRS. The top ten most diverse ornamental families of plants found at the SHRS site are Bignoniaceae, Arecaceae, Apocynaceae, Fabaceae, Moraceae, Malvaceae, Zamiaceae, Lythraceae, Combretaceae, and Asparagaceae. As a part of regenerating low individual accessions, the old shade houses and greenhouse are remodeled, cooling fans, and thermostats are replaced, and new irrigation lines have been created. More than 200 cuttings for various plumeria accessions and 100 cuttings of Ficus accessions (those that needed backup activities) were obtained from the field. They are treated with rooting hormones and regenerated under a mist bench. Scientists at SHRS, Miami, Florida characterized the floral volatile composition of Peltophorum pterocarpum an ornamental landscape tree. Two different chemical techniques were compared, dynamic headspace sampling and water distillation for gas chromatography-mass spectrometry. Several chemical constituents were isolated by headspace sampling but not by water distillation. Water distillation processed a higher content of oxygenated sesquiterpenoids and heavier chemical compounds such as diterpene and long-chain hydrocarbons, while dynamic headspace sampling isolated low molecular weight terpenoids and other compounds. This study presents floral volatile functions and their properties in pollination biology and their role in pest management issues. Objective 2: Throughout the fiscal year, a total of 2,126 propagules (seeds, budwood, rhizomes, corms) of various tropical and subtropical ornamental accessions were distributed to stakeholders. Ornamental researchers conducted more than fifteen field tours at USDA-SHRS, visited twelve Miami-Dade County commercial nurseries, and delivered ten scientific national/international research presentations to engage stakeholders in interactive activities. On April 12, 2024, a South Florida Stakeholder meeting was held, and on June 9, 2024, the USDA-SHRS community day took place at the SHRS facility. In these meetings, the ornamental team successfully engaged with over 600 participants to discuss the importance of national plant germplasm in agriculture, the economy, and the environment. Additionally, the ornamental team distributed over 500 plumeria germplasm cuttings and provided guidelines for growing these plants to the community. USDA-SHRS scientists, in collaboration with the University of Florida, are screening more than 200 coconut germplasm collections for various fungal pathogens that threaten the ornamental industry. Fungal pathogen isolation, characterization, disease indexing, and germplasm resistance and or susceptibility identification are planned in this study. The ornamental team's duties as part of the NP-301 germplasm maintenance plan are crucial. These include thoroughly scouting NPGS germplasm spread around 220 acres for safety, health, and pathogen infection, promptly repairing irrigation systems, diligently fertilizing the soil, expertly trimming and pruning plants, meticulously mowing the grass, and applying pesticides as needed through this objective work. In collaboration with the Montgomery Botanical Center in Miami, the SHRS has effectively acquired and conserved the rare ornamental species Sabal miamiensis, which is endemic to Miami-Dade County and is referred locally extinct in the wild in South Florida. Twelve S. miamiensis seedlings are regenerated through seeds and they are currently growing under greenhouse conditions. The newly identified species Sabal antillensis, endemic to the Dutch Caribbean islands of Cura�ao and Bonaire, was discovered in 2024. The new species was acquired from the Montgomery Botanical Center and successfully acclimatized in the fields of SHRS. Phoenix theophrasti the gap in the SHRS Phoenix palm species collection was also successfully regenerated and planted in the field. As a backup activity, these plants are also distributed/shared to the USDA-National Clonal Germplasm Repository for Citrus in Riverside, California following all the regulatory and phytosanitary certificate guidelines. The disease-free ornamental plant species such as Moringa oleifera, Lagerstroemia speciosa, Pseudophoenix segentii, and Washingtonia filifera that were regenerated through seeds and cuttings in full sun nurseries were successfully planted in the fields of SHRS. Objective 3: More than 300 seedlings of Fiji coconuts were successfully regenerated in the SHRS full-sun nurseries. Eight potential Fiji dwarf cultivar selections in three replicates are planted in a one-acre field plot (two locations) at USDA-SHRS and at USDA-Tropical Crops and Germplasm Research, Mayaguez, Puerto Rico (one location). The plants are fertilized twice a year and horticulturally important parameters such as plant height, diameter of trunk size, health, and leaf color are currently being collected. Ecological and weather parameters such as soil property types, relative humidity, temperature, wind, and rainfall are also being recorded. Florida's native palms are popular ornamental plants in the US, but their popularity has led to habitat extraction and population decline. The SHRS ornamental program is actively acquiring and conserving all fourteen known Florida native palms. The SHRS ornamental program has successfully preserved ten of them and is dedicated to safeguarding the remainder for inclusion in the USDA-GRIN global system. The long-term ornamental molecular lab technician position has been vacant at SHRS, and this has been recently recruited and successfully onboarded. High next-generation sequencing (NGS) quality native (Sabal spp.) and commercial palm (coconut) nucleic acids (Deoxyribonucleic acid and Ribonucleic acid) procedures were developed, and the extracted nucleic acids were delivered to the commercial lab for high-throughput NGS experiments by creating active contractual process. The USDA-SHRS Scientists have implemented an initiative to safeguard and preserve its elite germplasm through the adoption of tissue culture methods. To facilitate this endeavor, a dedicated tissue culture technician has been recently recruited (shared equally between Tropical Fruit and Ornamental CRIS projects) and onboarded to the project. The infrastructure necessary for a state-of-the-art tissue culture laboratory has been procured, encompassing essential equipment such as growth chambers, a laminar hood for sterile tissue culture procedures, LCD digital microscopy, and other vital tools. The ornamental program also supported Florida International Scientist in conducting a sabbatical ornamental plant tissue culture and molecular training programs at SHRS through a Non-Funded Cooperative Agreement. Since the tissue culture lab initiation, several ornamental low individual germplasms on palm, cycad, and Fabaceae seeds have been cultured on both solid and liquid media. A low individual ornamental germplasm Bahunia spp., has already been regenerated through tissue culture efforts at SHRS and is being transplanted to the greenhouse for acclimatization. Concurrently, research efforts have commenced to optimize and refine tissue culture processes, and molecular genetic laboratory techniques aiming to achieve efficient and reliable propagation and genetic characterization of the valuable ornamental tropical and subtropical germplasm. ACCOMPLISHMENTS 01 Phylogenetic relationships of Cuban and Caribbean ornamental plumerias. Plumeria, also known as frangipani, are trees and shrubs commonly found in tropical gardens around the world. They are known for their beautiful flowers, color, and fragrance. The Caribbean Islands have a high diversity of plant species, many of which are only found in this region. However, these species are at risk due to the loss of their natural habitat and are in danger of becoming extinct. Plumeria species have many physical characteristics and can be found in various ecological zones, from high-elevation rainforests to mountainous regions. A genetic study using the complete plastid genome sequences has shown that most Plumeria species are native to the Caribbean Islands, with a few also found in Central America and northern South America. The research study has also revealed the patterns of adaptive radiation and colonization routes within the region. Further research including the use of nuclear molecular markers and broader sampling will be necessary to better understand the relationships between Caribbean and mainland species and to provide a more detailed analysis of the biogeography of Plumeria. The outcome of this research has been published in the peer-reviewed scientific journal �Biological Journal of the Linnean Society�. 02 Transcriptome-wide genetic variations in the Leucaena genus for fingerprinting and breeding. The Leucaena genus, encompassing a diverse array of shrubs and trees native to the Americas, holds significant historical and practical value for humans. Among these, �Leucaena leucocephala� stands out for its nitrogen-fixing capabilities, making it a versatile species for erosion control, landscaping, multi-purpose farming, phytoremediation, paper production, and biofuel generation. However, its invasive nature in over 50 countries significantly limits its widespread utilization. Addressing this challenge, ARS researchers at Miami, Florida have focused on developing non-flowering or sterile Leucaena varieties through interspecific crosses. A rapid and reliable hybrid detection method is crucial to identify triploids at an early stage and prevent resource wastage on non-hybrid plants. This study published in the scientific journal �Agronomy� presents a novel approach utilizing mRNA-based transcriptome analysis to identify genetic variants across all the species of the genus Leucaena for the first time. The analysis led to the development of a platform capable of rapidly screening over 3000 interspecific crosses for hybridity using genetic markers from parental lines. This innovative method allows for the identification of triploids at the seedling stage, significantly reducing time and cost in breeding programs. Furthermore, the comprehensive variant database generated in this study serves as a valuable resource for future investigations into genetic diversity, mapping, marker-assisted selection, and breeding efforts within the Leucaena genus and fewer studied legume species in general. 03 Subtropical Horticulture Research Station-National Plant Genetic Resource sharing to stakeholders. The USDA-ARS-Subtropical Horticulture Research Station (SHRS) Scientific team distributed over 2000 ornamental plant samples to stakeholders this year. They also finished inventorying all the tropical and subtropical ornamental plants spread across 220 acres in the field. This included creating specific location- based records. This effort will enable better tracking of the variety of ornamental plants, their exact location, and passport information. These records will be helpful for those requesting information from the Germplasm Resources Information Network (GRIN) around the world.
Impacts
(N/A)
Publications
- Tiernan, N., Nakamura, K., Burns, C., Jestrow, B., Oviedo Prieto, R., Francisco-Ortega, J. 2023. Phylogenetic relationships of Cuban and Caribbean Plumeria (Apocynaceae) based on the plastid genome. Biological Journal of the Linnean Society, London. 397-412. https://doi.org/10.1093/ biolinnean/blad042.
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Progress 10/01/22 to 09/30/23
Outputs
PROGRESS REPORT Objectives (from AD-416): 1: Conduct research to develop genetic resource maintenance, evaluation, or characterization methods and, in alignment with the overall National Plant Germplasm System (NPGS) Plan, then apply them to priority tropical and subtropical ornamental genetic resources to avoid backlogs in plant genetic resource and information management. 2: Acquire, distribute, and maintain the safety, genetic integrity, health, and viability of priority tropical and subtropical ornamental genetic resources and associated descriptive information. 3: Broaden the diversity available for genetic improvement of subtropical and tropical ornamental crops by selecting superior genotypes from cultivars, landraces, and wild relatives that could be directly cultivated, or form the bases for novel breeding populations. 3A: Characterization and evaluation of Fiji Dwarf coconuts 3B: Developing molecular resources for Florida native palms and increasing the palm diversity in the NPGS. Approach (from AD-416): The long-term objectives of this project are to ensure a secure and diverse stream of new genetic variation and enhanced germplasm for the subtropical/tropical ornamental horticulture industry as well as generate and consolidate detailed information about the intrinsic genetic variability, systematic relationships, and ornamental merit of genetic resources via genetic characterization, systematic studies, and field evaluation. These objectives are non-hypothesis-driven research. The objectives form an integrated program of subtropical/tropical ornamental germplasm characterization, enhancement, and improved management practices. The program efficiently and effectively maintains the safety, genetic integrity, health, and viability of subtropical and tropical ornamental genetic resources. Collections of priority tropical and subtropical ornamental taxa and associated information will be strategically expanded and improved, distributing them worldwide to customers and stakeholders, emphasizing priority genera identified by appropriate Crop Germplasm Committees. Guided by new knowledge of the genetic relationships and valuable ornamental traits of poorly-known plants, superior new cultivars, and genetically enhanced populations and/or selections of priority subtropical and tropical ornamental crops will be developed. Application of high throughput genomic technologies involving next-generation sequencing (NGS) and phenomic approaches will be carried out to improve the selection of cultivars and explore native wild germplasm that would eventually enable breeders, biologists, and other stakeholders to use these genetic resources more effectively and efficiently. This report outlines the advancements made in new Project Number 6038- 13210-004-000D, which focuses on preserving, managing, characterizing, and distributing subtropical and tropical ornamental genetic resources. This project builds upon the findings of the previous Project Number 6038- 13210-003-000D, which focused on improving the management, and genetic characterization of subtropical and tropical ornamental genetic resources. The industry of ornamental horticulture is a diverse and rapidly expanding business worldwide, with Florida being the top state in the United States for floriculture sales at a whopping $1,115 million. The Subtropical Horticulture Research Stattion (SHRS) in Miami, Florida, has accumulated a vast number of diverse collections of ornamental germplasms, collected from different climatic conditions around the world. These germplasms are spread across 200+ acres in a haphazard manner. Due to a vacant curator position and the retirement of a key Investigator, maintaining and evaluating the ornamental germplasms has become difficult. A new ornamental lead scientist was brought on board to conduct a comprehensive field inventory of all subtropical and tropical ornamental genetic resources at SHRS. The germplasm field was categorized into North, South, East, and West blocks, and a detailed survey and inventory were conducted in a block-wise mode. Precise Global Position System (GPS) coordinates were collected using Garmin GPS Map 66st for over 1,750 ornamental accessions and the sub-tropical/tropical ornamental genetic resources dataset was created. The ARS scientists in Miami, Florida, ensure the upkeep of fields through various tasks such as repairing irrigation systems, fertilizing the soil, trimming and pruning plants, mowing the grass, applying pesticides, and manually cleaning out plots. The SHRS ornamental research team has been actively enhancing their germplasm collections by proactively removing misidentified and undesirable accessions of Thespesia grandiflora, yellow Malayan coconut, jasmine, and amaryllis plants. Additionally, they have cleared out massive clusters of multiple tall dead bamboo thickets. The team also successfully implemented germplasm selection, field plot design, and establishment of Fiji Dwarf coconut plants for genetic studies. Although the SHRS ornamental research team made interspecific cross progenies of Portlandia grandiflora x P. coccinea ornamental plants they were significantly reduced by freezes during the winter of 2021 and 2022. The team is clonally propagating and regenerating them in container trials under 50% shade in shade house conditions. Small populations of Portlandia selection accession will also be established in our walled-in area as a contingency against future hurricane damage. The research team obtained seeds of Handroanthus impetiginosus, a popular landscape ornamental plant, from Brazil and regenerated seedlings under controlled greenhouse conditions. As part of the stakeholder�s service request, the research team distributed over 1,500 propagules (i.e., seeds, budwood, rhizomes, corms) of different ornamental accessions during the fiscal year. The SHRS ornamental researchers conducted more than ten field tours at USDA-SHRS and delivered five scientific national/international research presentations to engage stakeholders in interactive activities. Our integrated program for subtropical/tropical ornamental germplasm maintenance, acquisition, characterization, and efficient distribution practices aligns with USDA National Program 301 strategic mandates. ACCOMPLISHMENTS 01 Precipitation is the main axis of phylogenetic turnover across space and time. The Subtropical Horticulture Research Station (SHRS) ornamental research team collaborated with the Legume Phylogeny Working Group to investigate the global question of what influences the distribution of organismal groups around the world. This has been a long-standing issue in macroevolution and biogeography for over two centuries. The significance of this global collaborative study is one of the first to address this longstanding question by deploying global- scale, high-resolution species distribution and bioclimatic niche plant data. The team aimed to uncover whether the distribution of lineages is governed by universal laws or influenced by regional factors. To achieve this, the team conducted targeted fieldwork in important tropical biodiversity hotspots, collected plant samples (underutilized economic and ornamental value) from the world's largest museum collections, and generated DNA sequence data for nearly 2,000 species across five continents. By combining robust phylogeny with bioclimatic niche data based on over 430,000 occurrence records, they gained new insights into the factors that determine the spatial and temporal turnover of lineages. The team's research outcome is published in a high-impact (IF � 14.14) scientific journal - Science Advances which highlights that water availability, rather than spatial distance or dispersal limitations, is the primary factor influencing turnover within continents. This research highlights the importance of museums, and plant conservatory repositories, worldwide as they hold vast amounts of data, both material and digital, which can offer valuable insights into longstanding questions in biogeography and macroevolution. All research data � taxonomic, geographical, and molecular � are made publicly available in recognized data repositories (GenBank, European Nucleotide Archive, and Dryad).
Impacts
(N/A)
Publications
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