Project Number: 3607-21000-011-13
Project Type: Specific Cooperative Agreement

Start Date: Sep 24, 2006
End Date: Sep 23, 2011

Objective:
To develop new or improved methods for hydroponic and greenhouse crop production and greenhouse disease and pest management; to clone geranium (Pelargonium spp.) genes involved in post-transcriptional gene silencing (PTGS) to boron and silicon; and to develop a consistent mechanical inoculation method for infecting geranium (Pelargonium spp.) with Tobacco ringspot viruses (TRSV) and Tomato ringspot viruses (ToRSV) present in several accessions derived from the Ornamental Plant Germplasm Center, Columbus, OH.

Approach:
A joint research project on Hydroponic and Soilless Culture will be initiated between the USDA, ARS and the University of Toledo. Proper management of insect and disease will enhance profitability and competitiveness of American growers. USDA, ARS will hire a Research Horticulturist and a Research Plant Pathologist to be located at the University of Toledo as an ARS Worksite of the USDA, ARS, Application Technology Research Unit in Wooster. Virus diseases of Pelargonium spp. are relatively common but different to assess because the host is usually not killed by infection. Develop a consistent mechanical inoculation method. Infect plants with TRSV and ToRSV and expose to varying concentrations of boron and silicon to determine their effects on viral disease and virus titers will be examined by serology and RT-PCR. The effects of photoperiod and temperature on virus infection will be examined in a similar manner. Since it may take some time to develop a consistent method of mechanical inoculation with TRSV and ToRSV in Pelargonium species, it would be advantageous to use plant material that is already infected. However, it would be important to first find out what viruses are present within these infected plants. At least two of the accessions obtained from the Ornamental Plant Germplasm Center are apparently infected with a ringspot virus. Therefore, we will need to characterize these viruses. This will be done by electron microscopy, serological techniques, and RT-PCR. Cuttings would be propagated from this previusly infected material and exposed to different nutrient and environmental conditions and their effects on virus infection would be analyzed as described above.