Location: Citrus and Other Subtropical Products Research
2023 Annual Report
Accomplishments
1. White strawberries, a new specialty fruit. Florida’s strawberry season encompasses December through March, with demand of high value specialty products during the Christmas holidays. White fruited strawberries originated in South America have the potential to fill such a niche market, but wild type fruit of Fragaria chiloensis have low yield and produce small and soft fruit. A result of several crosses with modern cultivars, Florida Pearl®‘FL 16.78-109’ is a white fruited strawberry with red achenes and a pink blush when ripe. ARS researchers at Fort Pierce, Florida, determined in sensory taste panels, that fruit of Florida Pearl® have similar firmness, sweetness and strawberry flavor than the two most commercially grown cultivars in Florida, ‘Florida Brilliance’ and Sweet Sensation®‘Florida 127’. On the other hand, sourness and titratable acidity were consistently lower than the two commercial cultivars, giving this variety a unique low-acid flavor. Florida Pearl® has been available in retail markets as a high-end fruit, and is being grown in Florida, California and Spain thus far.
2. Deciphering orange flavor and providing a new genetic tool for citrus breeders. Huanglongbing (HLB), or Citrus greening disease, has decimated citrus production in Florida and world-wide. The orange tree (Citrus sinensis) is sensitive to the disease and cultivars grown for juice have been particularly affected, impacting Florida’s agricultural economy. Over the course of six years, researchers in Fort Pierce, Florida, have analyzed hybrids showing various degrees of tolerance to the disease. Plant material included oranges, mandarins and mandarin hybrids with Poncirus in their background, a close relative of citrus imparting tolerance to cold and diseases. This large pool of data revealed that esters were necessary to impart orange flavor to juice, distinguishing it from mandarin juice. Further analysis identified a key gene in the ester pathway, and its expression was validated in citrus. A DNA marker was developed which could be used in marker-assisted breeding. This work will greatly expand the breeders’ toolbox to develop orange-like cultivars in a time of need. As new hybrids tolerant to HLB become available, processors will have the options to choose cultivars to produce juice with more orange-like or mandarin-like flavor.
Review Publications
Cruz, M., Plotto, A., Ferrarezi, R., Leite Junior, R.P., Bai, J. 2023. Effect of Huanglongbing on the volatile organic compound profile of fruit juice and peel oil in ‘Ray Ruby’ grapefruit. Foods. 12(4):713. https://doi.org/10.3390/foods12040713.
Bai, J., Rosskopf, E.N., Jeffries, K.A., Zhao, W., Plotto, A. 2023. Soil amendment and storage effect the quality of winter melons (benincasa hispida (thunb) cogn.) and their juice. Foods. 12(1): 209. https://doi.org/10.3390/foods12010209.
Whitaker, V., Dalid, C., Osorio, L., Peres, N., Verma, S., Lee, S., Plotto, A. 2023. Florida Pearl® ‘FL 16.78-109’ Pineberry. HortScience. 58:143-146. https://doi.org/10.21273/HORTSCI16951-22.
Jia, L., Wang, L., Xia, Q., Luo, W., Baldwin, E., Zhang, X., Jiang, L., Li, J., Zhao, Y., Qiao, X., Cao, Z., Wang, L., Bai, J. 2023. Expression patterns of volatile compounds during ‘FL 47’ tomato ripening and their response to exogenous methyl salicylate (MeSA) fumigation. Postharvest Biology and Technology. 203:112414. https://doi.org/10.1016/j.postharvbio.2023.112414.
