2004 Annual Report 1.What major problem or issue is being resolved and how are you resolving it (summarize project aims and objectives)? How serious is the problem? What does it matter? Invasive species are a primary threat to biodiversity. Invasive plants can threaten natural areas by competing with native species, altering habitats, and disturbing ecosystem processes. These impacts can result in the displacement and eventual elimination of native plants and animals, along with their unique genetic resources and ecological functions. While certainly not the only contributor, the nursery industry has introduced many invasive plants in North America that were originally intended for ornamental and landscape use. Mitigation of invasive species has therefore become a national priority for the nursery industry. In order to meet this national priority, a specific cooperative agreement was initiated between ARS, North Carolina State University, and Oregon State University to develop sterile or highly infertile cultivars of important nursery crops. This cooperative research will also examine methodology to develop sterility in plants, including the use of ploidy manipulations, wide crosses, and genetic engineering. This report serves to document the progress of the cooperative agreement between ARS and North Carolina State University. This research falls under National Program 301 - Plant, Microbial and Insect Germplasm, Conservation, and Development. The research involves germplasm evaluation and enhancement as well as safeguarding and conserving genetic resources. 2.List the milestones (indicators of progress) from your Project Plan. Because this research is part of a Specific Cooperative Agreement which can be renewed yearly, there are no milestones associated specifically with this project, as there are with a regular five-year project plan. Milestones for the associated in-house research are described in the report for CRIS 1230-21000-041-00D. However, specific objectives for this project are: Year 1 (FY2003) Acquire germplasm for genera of interest, which could include: English ivy, barberry, privet, amur maple, buckthorn, flowering pear, flowering crabapple, mimosa, lace-bark elm, and Norway maple. Year 2 (FY2004) Use mitotic inhibitors on seed or meristem material to produce tetraploid plants or sectors of plants of selected clones of the genera of interest. Year 3 (FY2005) Assess fertility in the tetraploids produced in Year 2. Use the tetraploids in 4X x 2X crosses to produce sterile triploids. Year 4 (FY2006) Continue crosses from Year 3 and tetraploid production from Year 2. Year 5 (FY2006) Begin to evaluate triploids for sterility and horticultural attributes. 3.Milestones: A. The following milestone for FY2004 (Year. 2)was substantially met. Mitotic inhibitors were used on seed or meristem material to produce tetraploid plants or sectors of plants of selected clones of amur maple, Norway maple, mimosa, trumpet vine, tutsan St. Johnswort, goldenraintree, privet, callery pear, and lacebark elm. B. Year 3 (FY2005) Fertility will be assessed in the tetraploids produced in Year 2. Occasionally the simple act of doubling the number of chromosomes of a plant is enough to render the plant infertile. If these tetraploids begin to flower, they will be used in 4X x 2X crosses to produce sterile triploids. Year 4 (FY2006) Crosses from Year 3 and tetraploid production from Year 2 will be continued in order to produce sterile triploid plants. Methodology on tetraploid production and crossing techniques will be generated that will be valuable to other scientists. Year 5 (FY2006) If triploids begin to flower, the trees will be evaluated for sterility and horticultural attributes. Sterile triploids will be beneficial not only to prevent invasion, but also to eliminate nuisance fruit, reduce pollen-induced allergies, and to improve flowering and re-blooming characteristics. 4.What were the most significant accomplishments this past year? D. This report serves to document research conducted under a Specific Cooperative Agreement between ARS and North Carolina State University to develop non-invasive nursery plants. Other details can be found in the report for the parent project, 1230-21000-041-00D. One common approach for developing seedless plants is to create triploids - plants with an extra set of chromosomes. Although triploids typically grow and function normally, they have an inherent reproductive barrier in that the 3 sets of chromosomes cannot be divided evenly during meiosis, thereby yielding unequal segregation of the chromosomes (aneuploids) or complete meiotic failure. Triploids can occur naturally or can be bred by hybridizing a tetraploid with a diploid. Natural polyploids frequently occur in nature. Tetraploids can be identified in existing populations or induced using mitotic inhibitors. These tetraploids are then used to develop triploids that combine infertility with other desirable traits using traditional breeding approaches. We are currently working on developing sterile triploids of a wide range of important nursery crops. We have confirmed tetraploids of Acer ginnala (amur maple), Acer platanoides (Norway maple), Albizia julibrissin (mimosa), Campsis x tagliabuana (trumpet vine), Hypericum androsaemum (tutsan St. Johnswort), Koelreuteria paniculata (goldenraintree), Ligustrum spp. (privet), Pyrus calleryana (callery pear), and Ulmus parvifolia (lacebark elm). We have confirmed triploids of Pyrus calleryana and we have begun working on Cytissus scoparius (scotch broom), Hedera helix (English ivy), and Miscanthus sinensis (maiden grass). As triploids are developed and begin to flower, we will begin evaluating fertility, seed production, seed viability, and other characteristics of interest. Ultimately, these plants will be released for production by the nursery industry. 5.Describe the major accomplishments over the life of the project, including their predicted or actual impact. This project has only been in place for one year. Therefore the major accomplishments are listed in the answer to Question 4.