Detection of fastidious bacteria causing citrus greening disease by nonradioactive DNA probes

摘要

The greening fastidious bacteria (GFB), also tentatively named Liberobacter, cause citrus greening disease. They unevenly inhabit the sieve tubes of host plants in low concentration. A highly sensitive and specific DNA probe, developed with DNA cloning methods has been used to detect GFB in infected citrus hosts. One of the clones containing a 0.24-kb GFB-specific DNA fragment was labeled with biotinylated nucleotides by a PCR-labeling technique. A dot hybridization assay with the biotin-labeled DNA probe has been successfully used for detecting GFB in various citrus hosts including mandarins, tangors, sweet oranges and pummelos. This probe could specifically react with all GFB strains from several Asian countries, but not with those from South Africa. The probe developed has specificity and sensitivity sufficient enough to detect minute levels of GFB infection and, therefore, can be used in quarantine of the Asian greening disease.