Submitted to: Florida State Horticultural Society Meeting
Publication Type: Proceedings
Publication Acceptance Date: 11/30/2012
Publication Date: 12/17/2012
Citation: Bai, J., Baldwin, E.A., Liao, H., Kostenyuk, I., Burns, J., Irey, M. 2012. Detection of 16S rDNA of Candidatus Liberibacter asiaticus by quantitative real-time PCR. Florida State Horticultural Society Meeting. 125:233-238. Interpretive Summary: Huanglongbing is a serious disease of citrus and affects flavor of orange juice. A method to detect the bacteria thought to cause the disease in orange juice was developed. This method first separated the pectin in the juice from the DNA, purified the DNA and eliminated inhibitor compounds allowing DNA detection.
Technical Abstract: Orange juice processed from Huanglongbing (HLB) infected fruit is often associated with bitter taste and/or off-flavor. The widely spread HLB disease in Florida is associated with Candidatus Liberibacter asiaticus (CLas), a phloem limited bacterium. The current standard to diagnose HLB for citrus trees is to take samples from midribs of leaves, which are rich in phloem tissues, and apply quantitative real-time PCR (qPCR) test to detect 16S rDNA of CLas. It is extremely difficult to detect CLas in orange juice because of the low CLas population, high sugar and pectin concentration, low pH and possible existence of an inhibitor to DNA amplification. The objective of this research was to improve extraction of DNA from orange juice, and detection of CLas by qPCR.