St. Paul, Minn. (September 1, 1998)—A new Hawaiian papaya, genetically resistant to papaya ringspot, is now being widely grown thanks to the cooperative efforts of plant doctors from Cornell University, the University of Hawaii, and the Pharmacia-UpJohn Company. This new papaya variety’s unique design will protect orchards from the significant yield decline experienced from ringspot infection.
"We’ve taken genes from the ringspot virus and inserted them into the plant," says Dennis Gonsalves, plant doctor at Cornell University and member of The American Phytopathological Society. "These genes defend the papaya from the disease."
This destructive disease, which rapidly spreads when aphids pick up the virus on their mouths while feeding on infected plants and continue to feed on healthy plants, was first detected in Hawaii in the 1940s and virtually eliminated large papaya production on Oahu in the 1950s. The papaya industry relocated to the Puna district on Hawaii island in the early 1960s. Plant doctors realized that Puna could not be kept virus free indefinitely and began a research program in the late 1980s to develop papaya resistant to the disease.
The new transgenic line, 55-1, given the name "UH SunUp," and a hybrid between 55-1 and "Kapoho" (the dominant papaya cultivar grown in Hawaii) named "UH Rainbow," were dramatically successful in field trials. This success, followed by tremendous cooperation between government agencies and grower groups resulted in the first seeds being released to papaya growers this spring. "The impact of the transgenic papaya will be known in the next several years," says Gonsalves. "We are hopeful that Hawaii papaya growers will find good fortune at the end of the ‘Rainbow.’"
The American Phytopathological Society (APS) is a professional scientific organization dedicated to the study and control of plant disease with more than 5,000 members worldwide.