Email: Muhammad Rezaul kabir* (rezaul.kabir@bwmri.gov.bd), Krishna Kanta Roy (kkroy@bwmri.gov.bd), Md. Abdul Hakim (mahakim@bwmri.gov.bd), Golam Faruq (dg.bwmri@bwmri.gov.bd), Abul Awlad Khan (aa.khan@bwmri.gov.bd), Md. Farhad (md.farhad@bwmri.gov.bd), Md Monoar Hossain (monoar.hossain@bwmri.gov.bd), Pawan Kumar Singh(pk.singh@cgiar.org)

Wheat blast has become an economically important disease in Bangladesh. Intercontinental jump of the disease caused by pathogen Magnaporthe oryzae pathotype Triticum (MoT) from South America to Asia and Africa and possibility of further spread to other vulnerable areas across the globe poses a serious threat to global wheat production. Development of wheat blast resistant varieties is the most effective and environmentally friendly approach to manage the disease. Available information suggests that field resistance for wheat blast is largely influenced by 2AS/2NS translocation from Ae. ventricosa. However, the effectiveness of 2NS translocation often influenced by the background genetic makeup of a particular wheat line.

Virulent strains of MoT on this translocation have been reported across South America over time which demands to find out new sources of resistance (especially non-2NS based) . In South Asia, several varieties have been released having 2NS translocation. Bangladesh Wheat and Maize Research Institute (BWMRI) has released 3 wheat blast resistant wheat varieties so far. Among them, “BARI Gom33,” a zinc bio-fortified blast-resistant wheat variety released in Bangladesh in 2017 is containing 2AS/2NS translocation.

This variety is covering approximately 40% of the total wheat growing area in Bangladesh. Dependency on single gene-based resistance (2NS translocation) over a large acreage may make this variety vulnerable to new MoT isolates. BWMRI has been working to identify both 2NS and non-2NS based resistance sources since 2017. Precision Phenotyping Platform (PPP) has been established with the aim of evaluating wheat germplasm with improved precision and identification of sources of resistance against the disease.

During 2023-23 growing season, fifty-one advance breeding lines was evaluated under artificial inoculated condition in PPP, Jashore. Out of this, twenty-four lines found 2NS positive where 8 lines showed less than 10% disease index. In contrast, among other 27 non-2NS lines, only 2 advanced lines showed resistant reaction.

Beside this, forty-five advance breeding lines have been screened under greenhouse conditions and found some 2NS/ non-2NS based promising lines (BAW 1272, BAW 1286, BAW 1328, BAW 1408, BAW 1422, and BAW 1424) against the disease. This non-2NS lines could be crossed with other non-2NS resistant lines (identified before at BWMRI) together with 2NS genotypes to accumulate resistance genes to achieve high and durable WB resistance.

Thematic area: Enhancing wheat resistance against biotic stresses