Evaluation of elite bread wheat lines for resistance to blast disease in Bangladesh

Abstract

A nursery comprising 25 elite bread wheat genotypes were evaluated to identify the sources of resistance to wheat blast caused by Magnaporthe oryzae pathotype Triticum (MoT), under artificial and natural infection experiments in three consecutive years from 2018 to 2020 in two different locations of Bangladesh. Seedling evaluation results revealed the absence of resistant and most genotypes displayed moderately susceptible to susceptible reaction. In the adult-plant field testing, six genotypes namely Borlaug 100, BARI Gom 33, BAW 1272, BAW 1280, BAW 1286, and BAW 1297 consistently showed resistant response to wheat head blast (WHB) infection with low levels of disease severity ranging from 0.2 to 8.1%. Among the remaining genotypes, some were moderately resistant, and the others exhibited various levels of susceptibility. The resistant genotypes that were most promising showed good agronomic performance under inoculated field trials. A significant positive correlation was observed between seedling and adult plant resistance. The above mentioned six genotypes also showed resistant reaction to WHB infection under controlled conditions when tested with three selected MoT isolates. The presence of 2NS/2AS translocation conferring WHB resistance was confirmed in four of the tested genotypes. Three (BAW 1272, BAW 1286, and BAW 1297) lines having non-2NS background exhibited good blast resistance under both the field and controlled conditions. These results will be useful for breeders and pathologists in exploiting the 2NS and non-2NS based resistant sources to pyramid and develop broad genetic based resistant germplasm.