Development of Resistance to Tomato Spotted Wilt and Similar Viruses inFloral Crops Progress Report — June 1998
Tomato Spotted Wilt Virus Resistance in Chrysanthemum
Date:
6/1/98
Title of Project:
Development of Resistance to Tomato Spotted Wilt Virus in Chrysanthemums.
Institution where work is being conducted:
North Carolina State University
Amount of Endowment Grant:
$14,878
Covering Period:
9/1/97 to 8/31/98
Anticipated Date of Completion/Final Report:
8/31/99
Individual(s) Conducting Project:
(List Project Leader First)
James W. Moyer - Title Professor
Telephone Number 919-515-7984
Margaret E. Daub - Title Professor
James W. Moyer and Margaret Daub
The goal of our research project has been to develop technology through genetic engineering, which will improve floral crop cultivars. We have continued to focus our research oil chrysanthemum because of its importance to tile industry and it has proven in our hands to be amenable to plant transformation mediated by Agrobacterium. We have worked to improve transformation protocols which will be adapted to genetically diverse genotypes. In addition to improving the technology for transformation of chrysanthemum, we have used virus resistance, specifically to tomato spotted wilt virus, as our primary model. Over 200 primary transformants (lines) were evaluated by thrips and /or mechanical inoculation procedures. During these experiments a range of susceptibilities to TSWV were observed. Recently the most susceptible lines were evaluated for horticultural characteristics which revealed another area of investigation related to stability of the commercially desirable phenotype during, the transformation and regeneration of specific cultivars.
During the past year our research has focussed on areas related specifically towards facilitating the licensing of technology and reagents used in the transformation process. Licensing and patenting of discoveries as well as tile utilization of reagents and technology are critical issues which must be resolved prior to commercialization of new or improved cultivars developed with these tools. Initial efforts were designed to construct a fully licensable vector for transformation. While considerable effort was expended in this endeavor, it became evident that a strategy was needed to obtain basic technology and vectors that were in existence. Focus is now on the individual elements of the vector. We are currently testing the OCS-MAS promoter obtained from Dr. S. Gelvin, Purdue University. Promoters are sequences of DNA which ‘drive’ the synthesis of RNA from the gene being introduced into the plant genome. The selection of this particular promoter is based not only on its ability to be licensed, but also that it theoretically causes elevated amounts of RNA from the resistance gene. This attribute makes it a particularly attractive promoter to use for virus resistance. Having abundant RNA from the resistance gene will theoretically favor the silencing of the attacking virus. Constructs containing the TSWV N gene driven by the OCS-MAS promoter are currently being tested.
Publications from this project:
- Sherman, J. M. Moyer, J. W. and Daub, M. E. 1998. A regeneration and Agrobacteriummediated transformation system for genetically diverse Chrysanthemum cultivars. J. Amer. Soc. Hort. Sci. 123: 189-194.
- Sherman, J. M., Moyer, J. W. and Daub, M. E. 1998. Tomato spotted wilt virus resistance in Chrysanthemum expressing the viral nucleocapsid gene. Plant Disease 82:407-414.
- Daughtrey, M. L., Jones, R. K., Moyer, J. W., Daub, M. E., and Baker, J. R. 1997. Tospoviruses strike the greenhouse industry: INSV has become a major pathogen on flower crops. Plant Disease 81:1220-1230.
- James W. Moyer & Margaret E. Daub 1998 Status of Management Options for Control of TSWV/INSV in Floral Crop Production Grower Notes Spring, 1998
