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.
Anonymous, 1988’ STAT-ITCF, Programme, MICROSTA, realized by ECOSOFT, 2 nd Ver.’ (Institut Technique des Cereals et des Fourrages: Paris) pp. 55.
Arabi, M.I.E., Jawhar, M. 2003. Pathotypes of Cochliobolus sativus (spot blotch) on barley in Syria. Journal of Plant Pathology 85:193–196.
Arabi, M.I.E., Jawhar, M. 2004. Identification of Cochliobolus sativus (spot blotch) isolates expressing differential virulence on barley genotypes in Syria. Journal of Phytopathology 152:461–464.
Arabi, M.I.E., Jawhar, M. 2007. Molecular and pathogenic variation identified among isolates of Cochliobolus sativus. Australasian of Plant Pathology 36:7–21.
Briggs, S.P., Johal, G.S. 1994. Genetics patterns of plant host-parasite interactions. Trends in Genetics 10:12–16.
Fetch, T.C., Steffenson, B.J. 1999. Rating scales for assessing infection responses of barley infected with Cochliobolus sativus. Plant Disease 83:213–217.
Flor, H.H. 1956. The complementary genetic systems in flax and flax rust. Advance in Genetics 8:29–54.
Strelkov, S., Lamari, E. 2003. Host-parasite interactions in tan spot (Pyrenophora tritici-repentis) of wheat. Canadian Journal of Plant Pathology 25:339–349
Valjavec-Gratian, M., Steffenson, B.J. 1997. Pathotypes of Cochliobolus sativus on barley in North Dakota. Plant Disease 81:1257–1278.
Watson, I.A. 1970. Changes in virulence and population shifts in plant pathogens. Annals Review of Phytopathology 8:209–230.
Wilcoxon, R.D., Rasmusson, D.C., Miles, M.R. 1990. Development of barley resistance to spot blotch and genetics of resistance. Plant Disease 74:207–210.
Yang, G., Rose, M.S., Turgeon, B.G., Yoder, O.C. 1996. A polyketide synthase is required for fungal virulence and production of the polyketide T-toxin. Plant Cell 8:2139–2150.
Zhong, S., Steffenson, B.J. 2001. Virulence and molecular diversity in Cochliobolus sativus. Phytopathology 91:469–475.
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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). https://doi.org/10.1556/CRC.35.2007.4.12
- spot blotch
- Cochliobolus sativus