International Journal of
Genetics and Molecular Biology

  • Abbreviation: Int. J. Genet. Mol. Biol.
  • Language: English
  • ISSN: 2006-9863
  • DOI: 10.5897/IJGMB
  • Start Year: 2009
  • Published Articles: 132

Full Length Research Paper

Two genotypes of Xanthomonas oryzae pv. oryzae virulence identified in West Africa

Onasanya Amos1*, M. M. Ekperigin2, A. Afolabi4, R. O. Onasanya2, Abiodun A. Ojo1 and I. Ingelbrecht3
1Department of Chemical Sciences, Afe Babalola University, Ado-Ekiti, Ekiti State, Nigeria. 2Federal University of Technology, Akure, PMB 704, Akure, Ondo State, Nigeria. 3Institute of Plant Biotechnology for Developing Countries, Ghent University, K. L. Ledeganckstraat 35, 9000 Ghent, Belgium. 4Biotechnology and Genetic Engineering Advanced Laboratory, Sheda Science and Technology Complex, PMB 186, Garki, Abuja, Nigeria
Email: [email protected]

  •  Accepted: 06 August 2013
  •  Published: 31 August 2013


Bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae (Xoo), is a very destructive rice disease worldwide. The aim of the present study was to examine if the Xoo virulence pathotypes obtained using phenotypic pathotyping could be confirmed using molecular approach. After screening of 60 Operon primers with genomic DNA of two Xoo isolates (virulent pathotype, Vr and mildly virulent pathotype, MVr), 12 Operon primers that gave reproducible and useful genetic information were selected and used to analyze 50 Xoo isolates from 7 West African countries. Genetic analysis revealed two major Xoo virulence molecular type (Mt) which were Mta and Mtb with Mta having two subgroups (Mta1 and Mta2). Mta1 (Vr1) subgroup genotype has occurrence in six countries and Mta2 (Vr2) in three countries while Mtb genotype characterized mildly virulence (MVr) Xoo isolates present in five countries. The study revealed possible linkage and correlation between phenotypic pathotyping and molecular typing of Xoo virulence. Durable resistance rice cultivars would need to overcome both Mta and Mtb Xoo virulence genotypes in order to survive after their deployment into different rice ecologies in West Africa.


Key words: Bacterial leaf blight, Xanthomonas oryzae pv. oryzae (Xoo), Xoo virulence pathotype, molecular typing, genomic DNA, Operon primer, Xoo virulence genotype, Xoo pathogen migration, West Africa.