Biochemical and pathogenic variation in strains of Xanthomonas campestris pv. mangiferaeindicae from

Abstract: In the present study, variations in 20 isolates of Xanthomonas campestris pv. mangiferaeindicae. the. causal agent of bacterial leaf spot or canker of mango, collected from mango growing areas of Andhra Pradesh, Kerala,Karnataka and Tamil Nadu were analysed. These isolates varied in their ability to liquefy gelatin, reduce nitrateand utilize carbon sources. In sensitivity to antibiotics, they showed resistance to kanamycin (50 ug/ml) and were sensitive to rifampicin (ISO ug/ml). In further analysis, 20 isolates gave 10 distant disease reaction patterns indicatingthe presence of 10 pathotypes or races among the 20 strains examined. Among the six varieties, Alphanso wasa highly susceptible and Bangalora was resistant towards most of the isolates. Each of the pathotype group was representedby one or two or more than two strains which clearly indicated that the pathogen is highly heterogenous in a particular location