TAXONOMY AND GENETIC DIVERSITY ASSESSMENT OF LANDSCAPE TREES AND SHRUBS
Floral and Nursery Plants Research Unit
Project Number: 1230-21000-050-00
Start Date: Aug 04, 2008
End Date: Aug 03, 2013
Objective 1: Accurately identify and characterize existing genetic resources, and elucidate their genetic relationships and genetic variation within species, in understudied groups of specialty crops (primarily woody landscape plants).
• Sub-objective 1.A. Elucidate relationships among selected species of elms (Ulmus).
• Sub-objective 1.B. Determine whether apomixis occurs in selected species of hackberry (Celtis).
• Sub-objective 1.C. Determine whether pollen competition affects the occurrence and frequency of interspecific hybridization in oaks (Quercus).
• Sub-objective 1.D. Characterize the evolutionary and systematic relationships for the approximately 11 species of the economically important landscape plant genus Catalpa, culminating in a biosystematic monograph for the genus.
• Sub-objective 1.E. Construct an initial systematic and phylogenetic analysis of the evolutionary relationships between the relatively few temperate species of the landscape plant Chionanthus and their many tropical congeners.
• Sub-objective 1.F. Carry out research projects relating to other families and genera to reach a broad audience in the form 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.
Objective 3: Investigate the identity and basic biological characteristics of selected invasive woody plants in the U.S.
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.