Biochemical characterization of Xanthomonas axonopodis pv. citri; A major impediment to Citrus orchards

Citrus is a significant crop playing an important role in Pakistan’s economy. However, its production is under constant threat by numerous pathogens resulting in considerable economic losses. Bacterial canker caused by Xanthomonas axonopodis pv. citri is a major limiting factor in the successful production of citrus. Isolates of the pathogen were collected from infected citrus orchard of Bahawalpur region. Bacterial pathogen was characterized by morphological evaluation, pathogenicity and biochemical tests including gram staining, catalase test, KOH test, simmons citerate test, starch hydrolysis test, methyl red and voges proskauer test, gelatin liquefaction test, casein hydrolysis test, kovacs’s oxidase test, nitrate reduction test and tween 80 hydrolysis test were performed which confirmed that citrus canker is caused by Xanthomonas axonopodis pv citri.