Two important diseases of rice are due to Xanthomonas
oryzae pathovars, bacterial blight (BB) caused by Xanthomonas
oryzae pv. oryzae and bacterial leaf streak (BLS) caused
by Xanthomonas oryzae pv. oryzicola. These two phytopathogenic
bacteria are highly related, showing more than 90%
similarity by the DNA:DNA hybridization and are difficult to
differentiate genetically and phenotypically (Rademaker et al.
2000; Swings et al. 1990).