Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/5/2005
Publication Date: 8/20/2005
Citation: Tennant, P., Ahmad, M.H., Gonsalves, D. 2005. Field Resistance of Coat Protein Transgenic Papaya to Papaya Ringspot Virus in Jamaica. Plant Disease. 80:841-847. Interpretive Summary: Papaya ringspot virus is the most important virus worldwide, occurring in areas such as the United States, South America, Asia, Africa, and the Caribbean. The virus has been effectively controlled in Hawaii by transgenic papaya and thus many other countries are interested in using transgenic plants to control the virus, including Jamaica. In a technology transfer program, transgenic papaya were developed at Cornell University, initially screened, and then subsequently tested in Jamaica. This report presents results of the field trials in Jamaica. The results suggest that the transgenic papaya for Jamaica is a good potential way to control the virus in Jamaica.
Technical Abstract: Transgenic papaya, containing translatable or nontranslatable coat protein (CP) gene constructs, was evaluated over two generations for field resistance to infections by Papaya ringspot virus in Jamaica. In general, transgenic lines of the RO generation carrying the translatable CP gene showed strong resistance (80%) against field infections while those with the nontranslatable CP gene were not as resistant (44%); showing tolerance, that is, attenuated symptoms, or severe symptoms after a long delay in the onset of disease. R1 offspring exhibited similar levels of resistance as the parental lines (50%), improved resistance (25%) or lower resistance (30%). In addition, transgenic lines exhibiting resistance to PRSV were gynodioecious, produced fruit of red flesh, average weight 260-535 g, and brixes of 11.5-13.5%. Fruits from the tolerant types showed similar attributes but they produced larger fruits (greater than 535g) and fruits of red or yellow flesh. Taken together, the transgenic lines tested appear to possess desirable horticultural characteristics and virus disease resistance that can be manipulated in subsequent generations for the development of a product with acceptable commercial performance.