Scientists examine citrus hybrids in fight against Citrus Greening Disease

Researchers, working to address the largest problem among citrus growers – Huanglongbing, or HLB- are investing in an old technique by creating new fruit species with increased resistance.

Scientists from the University of California - Riverside have turned to cross-breed citrus fruits to breed new hybrid species that have the best traits of their parent species. Ideally, these hybrids will enjoy the best tastes available and the resistance of some citrus strands to HLB.

A news release from UC Riverside mentions that Citrus greening disease, also known as HLB or Huanglongbing, has been reported in California. This is not a small thing, as the state is responsible for 80 percent of the United States' citrus produce - although none of the reports specify infection in commercial groves.

In an attempt to mitigate the spread in the state, the National Institute of Food and Agriculture has boosted the UC Riverside-led efforts with a $4.67 million research grant. UCR botanist leading the study, Chandrika Ramadugu, has already identified species of microcitrus that exhibit a natural resistance to the HLB.

Maintaining the fruit’s taste

Among the challenges in the effort is the risk of creating hybrid strands that have resistance to HLB but might not taste good. There is a need to generate numerous hybrids and then screen the best strains based on both resistance and taste to work around this risk. In his identified samples, the microcitrus, which includes the smaller Australian finger lime, is generally more bitter and has a sharper taste than other citrus fruits like oranges. The UCR team aims for the right genetic composition to create an HLB-resistant fruit with the right sweetness.