VIEW ARTICLE

Resistance

Assessment of Interactions Between Cultivated and Wild Wheats and Septoria tritici. Meira Yechilevich- Auster, Former graduate research assistant, Department of Botany, the George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel; Edna Levi(2), and Z. Eyal(3). (2)(3)Former graduate research assistant, and associate professor, respectively, Department of Botany, the George S. Wise Faculty of Life Sciences, Tel Aviv University, Israel. Phytopathology 73:1077-1083. Accepted for publication 31 January 1983. Copyright 1983 The American Phytopathological Society. DOI: 10.1094/Phyto-73-1077.

Populations and accession lines of diploid and tetraploid wild Triticum species with different genomes and cultivars of bread and durum wheats were evaluated for seedling resistance to seven isolates of Septoria tritici. Bulk populations of wild wheats expressed pathogenicity patterns ranging from highly resistant to susceptible and exhibited specific population x isolate interactions regardless of species, genomes, or environmental-climatological parameters. Of 22 T. monococcum boeoticum lines (genome AA), only two were susceptible. Accession lines of diploid wheats with genomes BB and DD exhibited several pathogenicity patterns. Of 47 wild emmer (T. turgidum dicoccoides) lines, 25 were resistant to all seven isolates of S. tritici, while the rest exhibited 14 identifiable pathogenicity patterns. Ten different pathogenicity patterns were identified among 17 cultivated wheats. Nine complementary interacting resistance-virulence genetic components were estimated by subjecting a reaction matrix involving 44 wheat lines (wild and cultivated) x seven isolates of S. tritici to EPIDAT analysis according to Person's incomplete gene-for-gene scheme. The number of resistance components ranged from eight in some lines of T. longissimum, T. speltoides, and T. turgidum dicoccoides to one in some T. turgidum dicoccoides lines. As many as seven resistance components were estimated in spring wheat line H574 and a similar number of virulence components were found in some isolates of S. tritici. Some pathogenicity patterns expressed by the wild wheats were unmatched by the tested cultivated wheats, and vice versa. This genetic variation in wild Triticum species is a utilizable germplasm reservoir for resistance to Septoria leaf blotch of wheat.