If there was any way that American-grown oranges could be saved without turning to genetic engineering, Ricke Kress at Southern Gardens Citrus would take it. But, in the real world, he’s found no choice but to pursue the strategy that saved Hawaii’s papaya crop — genetic engineering for a defense against a more powerful environmental foe.
That’s because a killer bacterium thought to be Candidatus Liberibacter asiaticus and known as Huanglongbing, HLB, or yellow dragon disease is devastating Florida oranges and cutting crop estimates to levels not seen since 1969. The threat to U.S citrus trees now also includes those in South Carolina, Georgia, Louisiana, Texas and California.
On Thursday, USDA weighed in with $1 million more for research that, up to now, has been largely funded by orange growers and processors and Southern Gardens, which is owned by the privately held U.S. Sugar Corporation.
USDA said it was going to provide a “unified emergency response framework” to the spread of citrus greening, which began almost a decade ago. Another $9 million in research into the ability of insects to spread HLB to healthy trees is included in the not-yet-passed Farm Bill.
USDA is also creating a coordinating group for its various units that are involved in finding defenses for citrus greening.
Florida’s $1.5-billion citrus industry could be a complete loss unless it soon finds a way to fight the disease. So far, growers have really been able to do little more than mount an organized retreat, leaving the destroyed trees behind the lines.
So, with no known cure and the only outcome being the death of its trees, Southern Gardens is funding research by Dr. Erik Mirkov at Texas A&M University. Mirkov, currently in Thailand, was not available, but Kress told Food Safety News that the work, now in field trials, is showing promise. USDA was also an early funder of the Texas A&M research.
The Texas A&M plant pathologist appears to have found a way to give citrus resistance to the greening diseases — adding more “green” with a couple of spinach genes. The transgenic trees have moved from the laboratory to actual field trials under all the regulations required when birthing a new genetically modified organism (GMO).
“It’s moving along as well and as quickly as it can be,” says Kress. He says the research project has moved from “lab to trees” and is following all the steps required for both the research and for the possibility that it will eventually qualify a new GMO product.
Kress says for Southern Gardens there will be only one test of success. “Proof of success will only come with the public, “ he says.
If Texas A&M saves American oranges, it will look a lot like Hawaii’s saving of the papaya with the creation of the Rainbow species to resist the ringspot virus, which threatened to eliminate the fruit from the islands. After it was created in 1998, the Rainbow papaya was consumed only in Hawaii, but Japan now imports it as well.
Citrus greening turns oranges into green, misshapen, and bitter-tasting fruit. Millions of acres of citrus crops have already been lost in the U.S. and overseas. Florida and Georgia are entirely under quarantine for citrus greening, as are portions of California, Louisiana, South Carolina and Texas. In addition, areas of the U.S. Territories of Puerto Rico and U.S. Virgin Islands are also under quarantines for citrus greening.© Food Safety News