Dennis Gonsalves
United States Department of Agriculture Agricultural Research Service, US Pacific Basin Agricultural Research Center

Papaya ringspot virus (PRSV) is often a limiting factor in the production of papaya worldwide. In 1992, PRSV was discovered in the district of Puna on Hawaii island, where 95% of Hawaii’s papaya was grown. Within two years, PRSV was widespread and causing severe damage to the papaya in that area. Coincidentally, a field trial to test a PRSV-resistant transgenic papaya had started in 1992, and by 1995 the ‘Rainbow’ and ‘SunUp’ transgenic cultivars had been developed. These cultivars were commercialized in 1998. ‘Rainbow’ is now widely planted and has helped to save the papaya industry from devastation by PRSV. Transgenic papaya have also been developed for other countries, such as Thailand, Jamaica, Brazil, and Venezuela. Efforts to have these papaya deregulated in these countries are ongoing.

Key words: Hawaiian papaya industry, papaya ringspot virus, pathogen-derived resistance, Rainbow, SunUp.