Taxonomy of Landscape Trees and Shrubs
Floral and Nursery Plants Research Unit
Project Number: 1230-21000-070-00
Start Date: Aug 04, 2013
End Date: Aug 03, 2018
The long-term objectives of this project are 1) to improve the understanding of interrelationships and the distribution of genetic variation (especially genome size and ploidy level) in understudied groups of specialty crops (primarily woody landscape plants), 2) to further develop the National Arboretum as a scientific resource, and 3) to investigate emerging and suspected invasive woody plants among groups of interest to the nursery industry and to National Arboretum plant introduction programs. These goals will be achieved through the following specific objectives:
Objective 1: Identify and characterize genetic resources in understudied priority groups of woody landscape plants, including, but not limited to, Ulmus, Celtis, and Carya, to elucidate their genetic relationships and variation within species. Sub-objective 1.A. Determine taxonomic and genetic relationships among selected species of elms (Ulmus). Sub-objective 1.B. Determine ploidy level and comparative genome size in Carya using flow cytometry. Sub-objective 1.C. Determine the distribution of apomixis and polyploidy in North American species of hackberry (Celtis) and their taxonomy and relationships. Sub-objective 1.D. Resolve taxonomic problems and determine the amount and apportionment of genetic diversity in selected white oaks (Quercus sect. Quercus). Sub-objective 1.E. Carry out research projects to meet needs for taxonomic research expressed by stakeholders, such as the production of regional floras and botanical manuals in collaboration with other scientists and horticulturists.
Objective 2: Maintain and enhance the National Arboretum Herbarium as a scientific resource and a collection documenting important agricultural research and germplasm. Sub-objective 2.A. Maintain and enhance the U.S. National Arboretum Herbarium as a scientific resource and a collection documenting important agricultural research and germplasm. Sub-objective 2.B. Maintain and enhance the U.S. National Seed Herbarium as a scientific resource and a collection documenting important agricultural research and germplasm.
Objective 3: Determine the identity and basic biological characteristics of selected invasive woody plants in the United States. Apply herbarium records of woody plant introduction and naturalization in the mid-Atlantic area to test statistical models for predicting characteristics contributing to invasive behavior in woody plants.
Investigations will utilize a variety of different data types, primarily morphological data, DNA sequence variation, and variation in single-locus DNA markers within variable sites in the genome, analyzed using phylogenetic analyses and other multivariate statistical methods. Organisms will be studied in the field, herbarium, laboratory, and garden.