Adaptation and Competition of Cochliobolus sativus Isolates on Barley


The competitive and adaptive capacity of Cochliobolus sativus were determined using the two major pathotypes in populations on barley in Syria Pt1 and Pt4, which differed widely in their virulence. Following greenhouse co-inoculation with the two pathotypes, Pt4 frequency average increased from the first to the last of four infection cycles, but decreased for Pt1. The number of lesions caused by Pt4 was individually higher than their mixture on both barley cultivars, Bowman and WI 2291. Moreover, the number of lesions was increased over the four cycles on both cultivars. The results suggest that isolates of different pathotypes would adapt at different rates in a mixed environment due to competitive advantage imposed by their virulence properties.


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Correspondence to M. I. E. Arabi.

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Arabi, M.I.E., Jawhar, M. Adaptation and Competition of Cochliobolus sativus Isolates on Barley. CEREAL RESEARCH COMMUNICATIONS 35, 1653–1659 (2007).

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  • spot blotch
  • Cochliobolus sativus
  • barley
  • adaptation
  • competition