Field Resistance of Coat Protein Transgenic Papaya to Papaya ringspot virus in Jamaica

Transgenic papayas (Carica papaya) containing translatable coat protein (CP T ) or nontranslatable coat protein (CP NT ) gene constructs were evaluated over two generations for field resistance to Papaya ringspot virus in a commercial papaya growing area in Jamaica. Reactions of R 0 CP T ransgenic lines included no symptoms and mild or severe leaf and fruit symptoms. All three reactions were observed in one line and among different lines. Trees of most CP NT lines exhibited severe symptoms of infection, and some also showed mild symptoms. R 1 offspring showed reactions previously observed with parental R 0 rees; however, reactions not previously observed or a lower incidence of the reaction were also obtained. The transgenic lines appear to possess virus disease resistance that can be manipulated in subsequent generations for the development of a product with acceptable commercial performance.