Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: August 29, 1998
Publication Date: N/A
Interpretive Summary: Leaf scald and ratoon stunting disease (RSD) are two major sugarcane bacterial diseases in the world. The bacteria causing these two diseases can infect and live in apparently healthy sugarcane plants for extended periods of time. Because sugarcane is propagated by cuttings (seedcane), the use of infected, but apparently healthy stalks as seedcane, can resulted in spreading the diseases to new fields, geographic regions, and countries. The primary method of control is to provide growers with seedcane free of the bacteria that cause leaf scald and RSD. Sensitive and reliable laboratory procedures are needed to identify the presence of the bacteria in infected sugarcane tissues even when symptoms are not visible. In this article, we describe in detail several recently developed DNA-based diagnostic protocols for the detection of these bacteria. These include a polymerase chain reaction (PCR) protocol for leaf scald and a PCR protocol and a Tissue-Blot DNA Hybridization Assay for RSD. These definitive DNA-based diagnostic protocols will be very useful tools in providing disease-free seedcane to growers. They will also assist quarantine personnel in preventing the geographic spread of these two bacterial diseases.
Technical Abstract: Several newly developed DNA-based molecular protocols are introduced for the diagnosis of two important sugarcane bacterial diseases. These include a polymerase chain reaction (PCR) protocol for the detection of Xanthomonas albilineans, the causal bacterium of leaf scald, and both a PCR protocol and a tissue blot DNA hybridization assay (TB-DHA) for the detection of Clavibacter xyli subsp. xyli, the causal bacterium of ratoon stunting disease (RSD). Both PCR protocols are specific, sensitive, and quick laboratory assays that detect all the strains of their targeted bacterial species collected worldwide. Application of these molecular diagnostic protocols to sugarcane quarantine and diagnostic laboratories will improve seed cane quality through the detection and elimination of these systemic pathogens, provide sugarcane growers with a practical, cost- effective diagnostic service, help evaluate the effects of cultural practices on disease epidemics, and assist in the identification of disease resistant germplasm.