Distribution of Karnal Bunt in North-Western Himalayas and Management Through Host Resistance

Abstract

Karnal bunt of wheat (Triticum aestivum L.), caused by Tilletia indica, poses a persistent threat to grain quality, seed trade and production stability. The present study was undertaken to assess the spatial distribution of Karnal bunt over two consecutive Rabi seasons (2021–22 and 2022–23) and identify resistant genotypes suitable for cultivation in the north-western Himalayan region. Hundred genotypes were evaluated under artificially induced epiphytotic field conditions. Of these, four genotypes (IC416075, IC145334, IC572925 and IC279616) exhibited complete resistance, recording 0.00% disease incidence and coefficient of infection. Forty-two genotypes were resistant, forty-six were moderately susceptible, six susceptible and two highly susceptible. Genotype × environment (G × E) interaction analysis, including AMMI and stability regression models, identified HD-1105, PBW-803 and PBW-824 as stable performers across environments. Hierarchical clustering and Mahalanobis distance analysis further highlighted substantial genetic divergence among the test genotypes. The findings underscore the significance of integrating field surveillance with resistance screening to identify stable, disease-resistant genotypes for effective management of Karnal bunt in vulnerable wheat-growing regions.