Integration of <i>Ny-Smira</i> -mediated PVY resistance into elite potato germplasm for sustainable production in Bangladesh

Abstract Potato cultivation in Bangladesh is severely constrained by potato virus Y (PVY), a non-persistent virus that causes major yield losses. This study aimed to develop PVY-resistant clones by introgressing the Ny-Smira resistance gene from the donor parent ‘Sarpo Mira’ into high-yielding breeding lines. Nine high-yielding advanced lines, derived from the cross Sarpo Mira × BARI Alu-53, were evaluated through molecular and phenotypic screening against PVY selected. Following RT-PCR confirmation, plants were inoculated with the prevalent PVY NTN strain. Clones C2-5 and C2-77 exhibited remarkable resistance with the lowest disease severity (5.1 and 8.5%, respectively), whereas C2-27 was highly susceptible (74.8%). Molecular analysis detected the presence of the Ny-Smira gene-linked marker (Ry186) in clones C2-5, C2-77, C2-33 and C2-80. In multi-location field trials, resistant clones C2-5 and C2-77 also demonstrated superior yield potential (46–48 and 42–46 t/ha, respectively), surpassing both parental lines. These elite clones represent valuable germplasm resources for breeding programmes aimed at developing PVY-resistant high-yielding potato varieties. Significance of the study What is already known on this subject? The Ny-Smira gene has been reported to confer resistance to Potato virus Y (PVY). What are the new findings? For the first time in Bangladesh, two advanced clones (C2-5 and C2-77) derived from Sarpo Mira × BARI Alu-53 were identified with the Ny-Smira gene, showing strong resistance to PVY NTN and significantly higher yields (42–48 t/ha) than their parental lines. What are the expected impacts on horticulture? These resistant, high-yielding clones provide valuable germplasm for breeding programmes, reducing pesticide reliance and enhancing yield stability in Bangladeshi potato production.