|Obando, Freddy - Louisiana State University|
|Hoy, Jeffrey - Louisiana State University|
Submitted to: American Phytopathological Society Press
Publication Type: Book / Chapter
Publication Acceptance Date: 10/12/2016
Publication Date: 1/1/2017
Citation: Obando, F.F., Hoy, J.W., Grisham, M.P. 2017. Detection and quantification of Xanthomonas albilineans in sugarcane using qPCR. In: Fatmi, M’Barek, Walcott, Ron R., Shaad, Norman W. editors. Detection of Plant-Pathogenic Bacteria in Seed and Other Planting Material, Second Edition. St. Paul, MN: American Phytopathological Society Press. p. 337-341.
Technical Abstract: Leaf scald, caused by Xanthomonas albilineans Ashby and Dowson (Xa), is a systemic, vascular disease of sugarcane that has been reported in more than 66 countries. Two forms of symptom expression are associated with leaf scald, a chronic and an acute form. Narrow ‘pencil line’ chlorotic streaks parallel to the main veins on leaves and a general bleaching of leaves are characteristic of chronic symptoms. Sudden wilting of mature stalks is associated with the acute phase of the disease. The disease can cause severe yield reduction and adversely affect juice quality. The disease also may also enter a latency phase in susceptible or tolerant varieties in which no symptom expression is observed. Latent infections may occur in stalks arising from plants that appear to have recovered from earlier chronic symptoms. Detection of latent infections seed cane is an essential component in an effective disease management program. Multiple techniques have been developed to detect and identify Xa including isolation on selective media, microscopy, serology, and polymerase chain reaction (PCR) assays. These techniques have been used to detect, identify, and differentiate strains of Xa, and to insure healthy seed-cane for crop production and germplasm exchange. Quantitative, real-time PCR (qPCR) described in the chapter provides increased sensitivity for detecting Xa and a quantitative technique that can be used for resistance screening.