Partner und Internationale Organisationen
(Englisch)
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A, B, CY, CZ, DK, FIN, F, D, H, IRL, I, NL, N, P, RO, SK, E, S, CH, GB
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Abstract
(Englisch)
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Stagonospora nodorum blotch (SNB) is a major disease of wheat (Triticum aestivum L.) caused by the fungal agent Stagonospora nodorum. Because of the quantitative nature of resistance of wheat to SNB, virulence data can not be easily obtained. To circumvent these difficulties and to accelerate the advances in resistance breeding we aimed to develop an in vitro test for a rapid identification of resistant genotypes towards SNB. In order to characterise the genetic background of S. nodorum leading to a selective extract, a broad set of crude extracts was produced using either different strains of S. nodorum cultivated as a mixture or as isolates alone. Crude extracts were then tested using the in vitro biological test to determine the germination inhibition of two wheat varieties: Forno (susceptible) and Arina (tolerant). Results indicate that the selectivity of the crude extracts was dependant on the set of strains used. Selective extracts were mainly obtained by the co-culture of strains and in fewer cases by strains showing a high sporulating rate cultivated separately, which is known indicator of strains virulence. Validation of the in vitro test by screening a population of 226 Recombinant Inbred Lines (RILs) derived from the cross of a resistant spelt variety (Oberkulmer) with a susceptible wheat cultivar (Forno) was aimed. However, standardization of the production of crude extract was difficult as selectivity varied among different batches of the same strain and because of the low stability of the crude extract. These results suggest that the in vitro test is not robust enough to screen large number of breeding material mainly due to large variations in extracts produced. Identification of the selective compounds in the crude extract would be needed to allow a standardization of the in vitro test system.
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