Isolation and molecular characterization of rice bacterial blight pathogen Xanthomonas oryzae pv. oryzae from Andaman islands, India

Bacterial blight (BB) caused by Xanthomonas oryzae pv. oryzae (Xoo) is a serious problem to rice cultivation in Andaman islands. A total of 24 Xoo isolates were collected from different rice growing areas of Andaman Islands. All isolates were identified through a series of morphological, biochemical and molecular approaches. Molecular variability among the isolates was analysed through PCr using multi-locus Jel1 and Jel2 primers which targeted repetitive IS1112 fragment of the pathogen. The results showed the grouping of isolates into 2 major clusters with high genetic variability among the isolates. Cluster i comprised 15 and cluster ii comprised 9 isolates. no correlation between genetic diversity in the pathogen and geographical origin of the isolates was however observed. The information generated in the present study would be much helpful to have a basic idea on genetic nature of pathogen in Andaman islands and to formulate successful BB disease management strategies with respect to island conditions.