Identifying sources of Karnal bunt (Tilletia indica) resistance by mining indigenous and exotic wheat accessions under Punjab conditions

Karnal bunt (KB), caused by Tilletia indica, is a majorquarantine disease of wheat that poses a threat to international trade and grain quality. The deployment of resistant cultivars represents the most sustainable and environment friendly strategy for managing this disease. In this context, the present study involved the systematic evaluation of 972 wheat accessions procured from Indian Council of Agricultural Research - National Bureau of Plant Genetic Resources (ICAR-NBPGR) in three consecutive cropping seasons (2019-20 to 2021-22) to identify stable sources of KB resistance. The test material was screened artificially at boot leaf stage using syringe inoculation method at Punjab Agricultural University, Ludhiana. Among the 972 accessions, 31.07% accessions consistently showed complete resistance with zero percent KB infection, while 11.83 % accessions demonstrated resistance response with KB infection levels ranging from 0.1 to 5.0 percent across all the three screening years. These resistant accessions will be crucial genetic pool for breeding programs, enabling gene pyramiding for multiple disease resistance to reduce fungicide dependence for sustainable wheat production. This study highlights the role of systematic screening for gene bank resources for the identification of durable resistance sources.