Australasian Plant Pathology (2010) 39, 63-68

Eva A. Antoni, Kasia Rybak, Madeline P. Tucker, James K. Hane, Peter S. Solomon, Andre Drenth, Manisha Shankar and Richard P. Oliver (2010)
Ubiquity of ToxA and absence of ToxB in Australian populations of Pyrenophora tritici-repentis
Australasian Plant Pathology 39 (1), 63-68
Abstract: Pyrenophora tritici-repentis, the causal organism of the necrotrophic foliar wheat disease tan spot [also known as yellow (leaf) spot in Australia] is an important disease in Australia and in many parts of the world. North American isolates of the pathogen have been shown to produce combinations of three host-specific toxins, ToxA, ToxB and ToxC. Each toxin interacts with a host sensitivity locus, respectively Tsn1, Tsc2 and Tsc1. The virulence of an isolate is partially correlated with the presence of these toxins and resistance in the host is associated with absence of the sensitivity loci. Breeding for resistance to tan spot can, therefore, be aided by knowledge of the prevalence of the toxin-encoding genes in local pathogen populations. Two of the toxins, A and B, are encoded by known genes and molecular tests for the genes have been developed. We screened a diverse collection of 119 tan spot isolates collected between 1984 and 2008 and from all affected regions of Australia (Queensland, New South Wales, Victoria and Western Australia). In all cases, the gene for ToxA was present and the gene for ToxB was absent. The implications for resistance breeding and epidemiology of the disease are discussed. We also define a diagnostic molecular marker for P. tritici-repentis.
(The abstract is excluded from the Creative Commons licence and has been copied with permission by the publisher.)
Link to article at publishers website
Database assignments for author(s): Richard P. Oliver, Peter S. Solomon, Manisha Shankar, Andre Drenth

Research topic(s) for pests/diseases/weeds:
general biology - morphology - evolution

---

Pest and/or beneficial records:

Beneficial	Pest/Disease/Weed	Crop/Product	Country	Quarant.
	Pyrenophora tritici-repentis	Wheat (Triticum)	Australia (South+SE)
	Pyrenophora tritici-repentis	Wheat (Triticum)	Australia (NT+QLD)
	Pyrenophora tritici-repentis	Wheat (Triticum)	Australia (Western)