The University of Hawai'i is conducting genetically modified crop research on bananas, tomatoes, petunias and lettuce in an effort to develop hardier, disease-resistant plants.

Researchers at UH's College of Tropical Agriculture and Human Resources also are trying to develop sugar cane that's genetically modified to produce a vaccine to protect against rotavirus ÷ a viral infection that can cause severe diarrhea and vomiting in young children.

The projects have been going on for several years, but have not been widely publicized. Other ongoing transgenic crop research at UH is being conducted on pineapple, orchids, anthuriums, taro, papaya and limes.

Genetically modified, or transgenic, crops are plants that have been altered by the transfer of genetic material from another species.

UH's drive to develop new transgenic crops is driven by economics, said Stephen Ferreira, an assistant specialist for plant and environmental protection sciences at UH.

"There's no question at a federal level ... more funds are being funneled or being targeted to some of these kinds of areas," Ferreira said. "Ten years ago you could hardly find money to do transgenic work." But because the technology is successful and has impact, funds are now available for transgenic research.

UH research into genetically modified papaya resulted in the development of a ringspot-virus resistant papaya, which has helped manage the impact of the virus.

However, UH's work on papaya and taro has caused a backlash among environmentalists and others. Cultural concerns about UH's work on genetically modified Hawaiian taro varieties ultimately forced the university to abandon that effort.

Despite the availability of research money, some scientists are reluctant to go into GMO work because of backlash of environmental and cultural concerns, said C.Y. Hu, associate dean and associate director for research at the UH CTAHR. However, Hu could not provide details such as the number of researchers working on genetically modified crop research or the amount of money spent.

"It's actually going down because we have a lot of faculty saying there's no point in doing this," he said.

That could ultimately hurt Hawai'i farmers, should new diseases surface locally, Hu said.

"If you don't want us to do that, we can accept that," he said. "But if we don't work on this and a disease comes in, it's going to wipe you out."

Apart from papaya, UH's remaining genetic crop research is being conducted in greenhouses or laboratories rather than in open fields, which lowers the risk of environmental exposure.

Opponents of genetic crop research and genetically modified food contend that not enough is known about the long-term impact of such products. They point out that many countries, including Japan, won't import transgenic papaya and that transgenic crops could cross-pollinate with nontransgenic plants and taint Hawai'i's image as a clean and natural environment.

So far UH's efforts have met with mixed success. For example, Hawai'i papaya growers now can grow transgenic papayas despite the presence of the damaging ringspot virus. However, genetically engineered papayas have yet to generate the market acceptance and higher sales prices that nongenetically modified papaya command in some markets. And a UH effort launched in 1995 to design a pineapple resistant to nematodes and mealybugs has yet to yield a marketable fruit.

Other ongoing research projects include transgenic virus-resistant lettuce, tomatoes and petunias and fungal resistant Chinese taro. The university also partners with Hawaii Agriculture Research Center on an effort to develop transgenic sugar cane that's resistant to the yellow leaf virus.

Now it wants to develop a better banana ÷ one that's engineered to resist infection from the bunchy top virus. Plants infected by the banana bunchy top virus suffer severely stunted growth and produce deformed fruit, or in advanced stages produce no fruit. The disease has been present in Hawai'i since the 1990s.

The project suffered a setback when UH researchers were unable to license genetically altered banana trees from researchers in Australia. As a result, UH researchers now have to develop their own virus-resistant banana, which "is years away," said Hu. "There's been some success, but it takes time."

Meanwhile, critics contend the $1.5 million spent so far on transgenic banana research could be better spent developing nongenetic techniques for managing the bunchy top virus.

"I think it's a big waste of money," said Sarah Sullivan, director for Hawaii Seed, an advocate for sustainable agriculture and a Hawai'i that's free of genetically modified organisms. "It's a good example of how unsuccessful GMO research has been."

Others complain that the university is focusing too much effort on genetic crop research rather than supporting alternative means of addressing pesky bugs. Hector Valenzuela, a UH vegetable extension specialist, said the state could have eliminated the ringspot virus by razing all papaya trees for a year or two.

"It would have been very difficult for farmers but it's a sacrifice for the next 50 years" of papaya growth, he said. "My position is there are many other approaches (that) could have been looked at."

Instead of razing trees, papaya growers opted to plant GMO papayas, which have not been a panacea.

"It's difficult because farmers are in a survival mode," Valenzuela said. "Of course they're going to take" a transgenic solution for ringspot.

Transgenic papaya proponents, which include some UH researchers and farmers, contend that there is no way to control the ringspot or bunchy top viruses without genetic engineering technology.

Cutting down all papaya trees "was the first recommendation that was made, but the decision made by growers was the economic hit was too costly to bear," said Ferreira, the UH assistant specialist. "These sustainable or alternative approaches have not been ignored. They've been studied. There's nothing new they have to offer."

Reach Sean Hao at shao@honoluluadvertiser.com.