Developing New Greening-Tolerant Citrus

Daniel CooperCitrus Greening, Industry News Release, Research

When Nian Wang pieces together sequences of genes, he hopes to make citrus varieties that are more tolerant to the deadly disease known as citrus greening, which has devastated a multibillion-dollar-a-year industry in Florida.

Nian Wang

Wang, a professor of microbiology and cell science with the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS), will help an investigation in which researchers take the best genes from one plant and transfer them into another. With that combination, Wang and the research team believe they’ll move closer to growers’ goal of citrus that copes better with greening.

Scientists from the University of California-Davis are leading the $4 million project, which is being funded by the Specialty Crop Research Initiative, part of the National Institute of Food and Agriculture, an arm of the U.S. Department of Agriculture. Wang is one of several investigators on the project.

Using his $735,000 portion of the grant, Wang and his team plan to bring multiple resistance-related genes from greening-resistant germplasms and put them into susceptible commercial citrus varieties. Those genes recognize specific features of the greening pathogen. Germplasms are the genetic material of germ cells.

Citrus greening disease, known scientifically as huanglongbing (HLB), has severely impacted the U.S. citrus industry in Florida and is spreading in Texas and California.

“There is a pressing need to identify therapies and treatment to protect citrus trees against HLB in commercial groves as well as develop new commercial varieties that are tolerant or resistant to HLB,” said Wang, a faculty member at the UF/IFAS Citrus Research and Education Center in Lake Alfred, Florida. Currently, there is no genetic combination that makes citrus resist greening. “Our approach to address this challenge is to increase the potential of citrus’ own immunity.”

Wang wants to inhibit the spread of Candidatus Liberibacter asiaticus — the bacterium that causes greening — by boosting citrus immunity. This proposed research will develop HLB control therapies and generate disease-resistant varieties, he said. Additionally, Wang’s research will further help citrus breeders identify the genes they need to develop greening-tolerant varieties faster.

“The outcome will provide sustainable solutions that can be deployed in the field in the near- to mid-term and help manage the severe losses inflicted by HLB,” Wang said.

Source: University of Florida Institute of Food and Agricultural Sciences