Genetically engineered papaya that resists the devastating papaya ringspot virus has saved Hawaii's papaya industry. But efforts to grow PRSV-resistant papaya in developing countries are stalled, and researchers aren't sure why, according to a retired Cornell University plant virologist.

Dennis Gonsalves, now director of the U.S. Department of Agriculture's Pacific Basin Agricultural Research Center in Hilo, Hawaii, and professor emeritus of plant pathology at Cornell in Geneva, N.Y., reviewed how the transgenic papaya was successfully developed, deregulated and commercialized in Hawaii.

"But despite our efforts to produce and implement PRSV-resistant papaya in such developing countries as Venezuela, Thailand, Brazil, Jamaica and Bangladesh, deploying the crop in these countries has been nearly aborted or delayed," Golsalves says.

Speaking at the recent American Association of the Advancement of Science meeting in St. Louis, Golsalves says, "It is safe, but it has not been transferred to a point where it's available to the people. Our challenge now is figuring out why and to determine how we get it to the end user in a timely manner."

The papaya industry in the Puna district of Hawaii, where 95 percent of the state's papayas are grown, would not be in existence today, Gonsalves says, without genetically engineered PRSV-resistant papaya.

Gonsalves says that studying Hawaii's experience in saving its papaya industry with genetically engineered PRSV-resistant papaya should shed light on why developing countries aren't following suit.

"It is a case worthy of study to see if more universities or governmental agencies can do this kind of work," Gonsalves says. "If you want to look for an ideal case, it's tough to beat the papaya. Big corporations are not involved—we're just small university or government scientists doing the work, and the growers control it in the case of Hawaii. It's a great model, so why is progress being delayed?"

The papaya in Hawaii, he says, also can serve as a test case for genetically engineered food crops developed in the United States for other countries, such as Japan.

"With the papaya, people will be choosing a product that they will consume fresh, unlike nearly all of the currently genetically engineered corn and soybean," he says.