Genome project brings citrus industry closer to stopping greening

Genome project brings citrus industry closer to stopping greening

Researchers from California and Florida reached a milestone in the in the search to develop a citrus greening-resistant tree by sequencing the genome of a plant that’s closely related to citrus trees.

Scientists believe they’ve found genes to start making trees more tolerant or resistant to certain diseases, including huanglongbing, HLB, also known as citrus greening.

University of Florida-Institute of Food and Agricultural Sciences (UF/IFAS) researchers, along with scientists from the University of California-Berkeley, the U.S. Department of Energy’s Joint Genome Institute and the University of Florida’s Interdisciplinary Center for Biotechnology Research worked on the project, according to a University of Florida news release.

The trifoliate orange genome, which would take 54,000 pages of paper to print, will help citrus tree breeders to guard against invasive pests and viruses.

“Very importantly, trifoliate orange and its hybrids have genes that can confer high tolerance to citrus greening and resistance to the Asian citrus psyllid, the insect that transmits greening to citrus,” said Zhanao Deng, a senior author on the new UF/IFAS-led study, said in the release. “This genome can be used as a reference template to sequence widely used trifoliate orange hybrid rootstock varieties.”

Fred Gmitter, UF/IFAS professor of citrus breeding genetics and co-author of the study, said trifoliate orange is rarely seen, because it’s usually the rootstock of the tree and are underground. Trifoliate and its hybrids were used as rootstock for more than three million citrus trees in Florida in 2018-19.

“Our trifoliate orange genome will allow scientists to develop new tools that can more speedily transfer beneficial genes into sweet oranges, grapefruit and breeding of new scion cultivars, which grow above the ground,” Deng said in the release.

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