DNA fingerprinting and virulence analysis of Xanthomonas oryzae pv. oryzae isolates from Punjab, northern India uri icon

abstract

  • DNAs of 693 isolates of bacterial blight pathogen of rice, Xanthomonas oryzae pv. oryzae (Xoo), were characterized using PCR-based primers p(JEL1) and p(JEL2). The pathogen populations were grouped into 97 haplotypes based on DNA-banding patterns. An un-weighted pair-group method using arithmetic averages (UPGMA) indicated a high level of diversity in the pathogen isolates (51 lineages of Xoo at a 70% similarity level). Among these, lineages 5, 7, 27, and 29 are widely distributed and others are localized in the northern region of India. The isolates represent lineage-27, were prevalent in the entire disease-prone area in the region except at Ferozepur. Pathotyping data of the representative isolates of each lineage also indicate 17 different reaction patterns on a set of isogenic lines. Resistance genes xa8 and Xa21 were the most effective followed by xa5, and Xa7 against Xoo isolates prevalent in northern India. Different genes in combinations (xa5+xa13, xa5+Xa21, xa13+Xa21, and xa5+xa13+Xa21) in IR24 genetic background provided better protection against all the pathogen isolates tested in this study than did the component genes.

publication date

  • 2003
  • 2003