Project Number: 1230-21000-053-00
Project Type: Appropriated

Start Date: Apr 14, 2008
End Date: Apr 13, 2013

Objective:
Develop stress, disease, and pest-tolerant cultivars of common and underutilized landscape trees suitable for urban areas and height-restricted planting sites. Develop disease- and insect-screening assays for identifying resistant parent taxa and hybrid progeny. Identify interspecific and intergeneric barriers to introgression of desired traits into adapted germplasm. Develop non-invasive tree cultivars, via wide-hybridization and inter-ploid crosses, to limit naturalization and gene-introgression into natural populations. Quantify genome sizes and ploidy levels in related taxa and identify parental taxa for interploid crosses. Develop methods for ploidy-manipulation of vegetative meristems to facilitate interploid crosses and ploidy bridges. Use molecular techniques for hybrid verification and genetic-relatedness tests within cultivated germplasm of important tree species.

Approach:
Develop in vitro and in situ disease and insect screening assays for identifying resistant parent taxa and hybrid progeny; determine inter- and intrageneric barriers to introgression of resistance and ornamental traits into adapted germplasm via controlled pollinations and fluorescence microscopy; quantify genome sizes and ploidy levels using flow cytometry and manipulate ploidy level via mitotic inhibitors; verify hybrid and cultivar parentage using molecular markers. Evaluate progenies and make clonal selections for pest resistance, stress tolerances, non-invasiveness, and ornamental traits. Test plants for geographic and climatic adaptability and horticultural traits through cooperative procedures.