Submitted to: Plant Disease
Publication Type: Peer reviewed journal
Publication Acceptance Date: 8/28/2001
Publication Date: 2/20/2002
Citation: Interpretive Summary: In May 1992, papaya ringspot virus was discovered in the Puna district on the island of Hawaii where over 95% of Hawaii's papayas are produced. The virus affects the fruit, causing a seventeen million pound loss in production. Two new lines were developed that showed resistance to papaya ringspot virus. Two experiments were conducted that found the lines would hold resistance under field conditions. The resulting production of papayas that are commercially acceptable has saved the papaya industry in Hawaii from destruction and will keep quality fruit available for consumers.
Technical Abstract: Two field trials to evaluate transgenic resistance to Papaya ringspot virus were established in Puna, island of Hawaii. One trial included 'SunUp' (a homozygous transformant of 'Sunset'), 'Rainbow' (a hybrid of 'SunUp'), 'Kapoho' (a widely used non-transgenic cultivar) and '63-1' (another segregating transgenic line of 'Sunset'). The second trial consisted of .4 ha block of 'Rainbow' simulating commercial plantings. Both trials were surrounded by a matrix of 'Sunrise' (a susceptible sibling of 'Sunset'). The matrix served to contain and trace pollen flow from transgenic resistance plants and as a secondary inoculum source. At the end of one year 100% of the non-transgenic resistance control plants and 91% of the matrix plants were infected and no infection was observed on the transgenic resistance plants. This data suggests that the transgenic 'SunUp' and 'Rainbow' offer a good solution to the papaya ringspot virus problem in Hawaii.