Transgenic Citrus Studies Progressing

Spray pesticides? Inject antibiotics? CUPS? Or?

The search for solutions to HLB has gone on for nearly two decades. Growers and researchers have learned ways to improve nutrition programs to keep trees alive and productive, but nowhere near at the level of the days before the disease.

One area of research that could yield a tree resistant to HLB is genetic engineering. There are no transgenic citrus trees produced commercially anywhere in the word, but trees are being developed by scientists.

Michael Rogers, director of the University of Florida Institute of Food and Agricultural Sciences (UF/IFAS) Citrus Research and Education Center, discussed some of that research during the October All In For Citrus podcast episode.

While the industry has been cautious about genetically modified organisms (GMOs), the UF/IFAS citrus breeding team has been developing transgenic citrus varieties over the years. This is to keep the GMO option on the table and available if it can benefit the industry.

“Dozens of transgenic lines of citrus with robust tolerance to canker and/or HLB have been developed and tested in the greenhouse,” Rogers said. “Many of those lines are moving into field trials this year.”

In addition, researchers are testing a transgenic rootstock on a non-transgenic sweet orange variety. Rogers said the idea here is to see if the rootstock can pass on its HLB tolerance to the scion.

There are currently five lines of genetically modified Hamlin orange and one line of Duncan grapefruit that are moving through research and development. Field trials of these varieties were planted in 2019 and 2021. All have been infected by HLB in the field but are showing low HLB symptoms. Yield and quality data on these lines will be collected over the next two seasons. Requests for regulatory approvals are underway, which would allow the trees to be planted commercially.

Rogers expects the regulatory approval process will take more than two years, if successful. He emphasized this work has been ongoing for years now, so growers will have a GMO option if they need it and choose to plant it.

To learn more about this research, listen to the latest episode of All In For Citrus. The podcast is a partnership between UF/IFAS and AgNet Media.

From: Citrus Industry, https://citrusindustry.net/2023/10/30/transgenic-citrus-studies-progressing/