Characterization of Brassolaeliocattleya Raye Holmes ‘Mendenhall’ - putatively transformed for resistance to Cymbidium Mosaic Virus

This research was supported through a grant from the USDA-NIFA (National Institute of Food and Agriculture). The corresponding author and her student (NS) wish to thank USDA-NIFA and Windward Community College Chancellor’s Advancement Fund for travel funding to present this poster at the Fourth Scientific Conference on Andean Orchids in Guayaquil, Ecuador. Special thanks to Professor David Christopher at University of Hawaii at Manoa for the National Science Foundation grant MCB-0958107 for research stipend given to NS; to Mrs. Scott Mitamura from Foster Gardens of Honolulu for providing virusinfected Blc. Waikiki Gold x C. Harrisoniana plants. References c) Orchids are infected by more than 50 different viruses. Infected plants bloom less efficiently, lack vigor, and produce lower quality flowers than healthy plants. One of the most important viruses, with worldwide distribution, is Cymbidium Mosaic Virus (CyMV). It is a single-stranded RNA virus belonging to the group of rod-shaped potexviruses. In previous research, a Brassolaeliocattleya orchid was transformed with the coat protein gene from Cymbidium Mosaic Virus using an agrobacterium-mediated method. The aim was to improve resistance of the orchid to CyMV. Protocorm-like bodies of Brassolaeliocattleya Raye Holmes ’Mendenhall’ were used. A full-length coat protein gene of CyMV was cloned into a vector, which also contained Kanamycin resistance for the selection of transformants. The coat protein was inserted under control of a CaMV 35S promoter in an anti-sense orientation. Putative transformants were selected for four months on media containing 25 !g/mL Geneticin Disulfate (G418). The objective of the present study is to further investigate and characterize the putative transgenic lines, which have been selected for antibiotic resistance. Molecular characterization of transformants is ongoing. Micropropagation is being carried out to multiply the transformed plant material. Plantlets will be used to develop an in-vitro inoculation assay to test the resistance to CyMV. Future work will investigate the resistance of these lines to the Cymbidium Mosaic Virus.