Three University of Florida (UF) scientists will use US$10.52m in federal grants to study ways to help beleagured citrus growers cope with citrus greening disease, including research on genetic editing that may produce potentially resistant fruit and trees.
Since greening – or huanglongbing (HLB) -- was first reported in Florida in 2005, Florida’s citrus production has shrunk by more than 50 per cent, according to UF/IFAS research.
The money comes from the National Institute of Food and Agriculture, a division of the US Department of Agriculture, and goes to two researchers at the UF/IFAS Citrus Research and Education Center (CREC) in Lake Alfred, Florida and one scientist on the main UF campus in Gainesville.
“There has been a tremendous amount of progress made in developing solutions to HLB,” said Michael Rogers, director of UF/IFAS CREC. “As we get closer to having that solution in hand, these grants received from the USDA are critical to completing the research underway that shows the most promise for winning the fight with HLB.”
Nian Wang, a UF/IFAS associate professor of microbiology and cell science who’s based at CREC, will use US$3.6m to generate non-transgenic, greening-resistant citrus varieties by editing genes that make citrus susceptible to the greening pathogen.
This is done by using Clustered Regularly Interspaced Short Palindromic Repeats (CRISPR) technology, with the goal of Wang’s research to develop tolerance or resistance to greening in citrus varieties that are commercially important in all citrus production regions. He and his team are using strategies and objectives based on industry input.
Gene editing is such a promising technology that two research groups at UF/IFAS have been funded, Rogers said. Zhonglin Mou, a UF/IFAS associate professor of microbiology and cell science in Gainesville, will use US$2.95m to develop greening-resistant or tolerant citrus trees by targeting negative regulators of the citrus immune system.
“Restoration of the Florida citrus industry requires new trees that better tolerate the infection or reduce the spread of the disease,” he said.
Arnold Schumann, a UF/IFAS professor of soil and water sciences, received US$3.5m to further his research on a screening system that protects citrus from the Asian citrus psyllid, the tiny bug that transmits greening to citrus trees. Schumann uses a system called Citrus Under Protective Screen, or CUPS.
“Citrus greening makes it very difficult to profitably grow citrus with conventional methods,” Schumann said.
But UF/IFAS research has shown that high-yielding trees can be grown under protective screen structures to produce disease-free citrus by completely excluding the psyllid and therefore the disease, he noted.
“Our research and Extension team from Florida, California and Australia will be developing solutions for profitably growing disease-free citrus in screen houses,” Schumann said. “This new protected agriculture system will initially target the Florida and California citrus industries but is broadly applicable to any citrus groves where the Asian citrus psyllid must be completely excluded in order to prevent citrus greening disease.”