Submitted to: Septoria International Workshop Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 9/20/1999
Publication Date: N/A
Citation: N/A Interpretive Summary: Septoria nodorum blotch is a common disease worldwide in cereal crops and grasses. Some isolates of this fungal pathogen, Stagonospora nodorum, reportedly cause more severe damage to crops than the others. It is important to know the reasons behind this phenomenon for future selection and development of resistant germplasms. In this study, we found less aggressive isolates cause less symptoms on wheat, triticale and rye. They have a "+" sexual mating type and the same ribosomal DNA sequence as the highly aggressive ones. But they are genetically different from the highly aggressive isolates as determined by molecular analysis. This result indicated the possible involvement of genetic elements in infection aggressiveness. The results of this work will help to develop crops for disease controls and to increase grain yield for farmers.
Technical Abstract: Two less aggressive Stagonospora nodorum isolates, 9074 and 9076, were characterized by inoculation tests, mating ability and molecular tools. As expected, they caused mild symptom severity on wheat, triticale and rye. They crossed with other S. nodorum isolates and had "+" mating type determinant(s). These two isolates also had the same restriction patterns and sequences in the ITS region of rDNA similar to other S. nodorum isolates. With AFLP analysis, it was concluded that these less aggressive S. nodorum isolates were closely related and were genetically different from highly aggressive ones.