Location: Subtropical Horticulture Research
2023 Annual Report
Objectives
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
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.
Progress Report
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
1. 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).
