Characterizing phenotypic diversity of Xanthomonas oryzae pv. oryzae in Punjab

Rice growing areas of Punjab were surveyed during Kharif 2009 and 2010 for the occurrence of bacterial blight disease. Highest disease occurrence (35.6%) and severity (19.9%) was recorded in Tarn Taran district followed by Ropar and Patiala districts respectively, while no disease was observed in Bathinda district. The disease showed widespread occurrence in Punjab but its incidence was more pronounced in Northern-plain region (17.7%) as compared to Western-plain region (1.4%). One hundred five (105) strains of Xanthomonas oryzae pv. oryzae collected from various rice growing regions of the State were further characterized for differences in their biochemical and physiological characteristics. Numerical analysis of phenotypic features revealed that all strains were associated at 50% similarity coefficient.