 Copyright The American Phytopathological Society |
Disease Note. First Report of Leaf Scald of Sugarcane (Xanthomonas albilineans) in Guatemala. W. Ovalle, Plant Pathologist, CENGICA, Guatemala. J. Comstock, Research Plant Pathologist, Canal Point, Florida; J. Juarez, Sugar Cane Researcher, Magalena Sugar Mill, Guatemala; and G. Soto, Plant Breeder, CENGICA, Guatemala. Plant Dis. 79:212. Accepted for publication 12 October 1994. Copyright 1995 The American Phytopathological Society. DOI: 10.1094/PD-79-0212B. In July 1992, typical leaf scald symptoms were observed on sugarcane (a complex hybrid of Saccharum species) in a commercial field in Guatemala. Affected plants of cv. Mex 69-430 exhibited whitish "pencil lines" on leaf blades, chlorotic leaf stripes, and side-shoots. Minute yellowish colonies were consistently isolated from the "pencil-lines" on nutrient agar. Bacterial suspensions of these colonies were used to inoculate 5-wk-old plants of cv. Louisiana 61-49. Typical symptoms developed after 28 days and the pathogen was reisolated. To identify the causal agent, dot immunobinding assays (1) were performed on juice extracted from symptomatic stalks collected from 18 cultivars from four fields at various altitudes. Nine of the 18 cultivars assayed were positive using a monoclonal antiserum specific for serovar 1 of Xanthomonas albilineans (Ashby) Dowson, donated by A. M. Alvarez, Univ. of Hawaii, Honolulu. Leaf scald had not been reported previously in Guatemala. Reference: (1) J. C. Comstock and M. S. Irey. Plant Dis. 76:1033, 1992. |
