Figure: Juvenile form of the Asian citrus psyllid, the insect that transmits a bacteria responsible for Huanglongbing. Photo Source: United States Geological Survey

Citrus Greening Disease, also known as Huanglongbing (HLB), has crippled Florida's citrus industry and has already been detected in California, which grows 80% of America's fresh citrus.

The National Institute of Food and Agriculture is supporting scientists at the University of California, Riverside (UCR), the University of Florida, and the U.S. Department of Agriculture's Agricultural Research Service to develop plants with natural tolerance to HLB. UCR geneticist Danelle Seymour and plant pathologist Philippe Rolshausen will examine 350 citrus hybrids developed and grown by project collaborators in Florida. All trees in the set are already infected with HLB, yet they live longer, are healthier, and yield more fruit than their infected relatives.

Seymour said that as their data set is so large, they can identify plants with levels of tolerance that exceed current commercial varieties. In addition to searching for parts of the hearty hybrids' genomes responsible for their tolerance to HLB, the scientists will also be checking for plants that have resistance to other pathogens that are already in California such as nematodes and phytophthora.

For more details, read the article in UC Riverside News.

See https://www.isaaa.org/kc/cropbiotechupdate/article/default.asp?ID=19194 (Jan 5 2021)