Seedling Resistance of Wheat (Triticum aestivum L.) Varieties to Virulent Races of Puccinia graminis f. sp. tritici

Abstract

Wheat (Triticum aestivum L.) is a globally important staple crop and a primary source of food, feed, and income for millions of people. One of the most threatening diseases is stem rust, caused by Puccinia graminis f. sp. tritici, which has re-emerged as a serious concern in many wheat-growing regions. The Puccinia species that cause wheat rusts are extremely dynamic and constantly evolving, producing new isolates by somatic recombination, introduction, mutation and selection. The present study (2024–25) was conducted at the Regional Wheat Rust Research Station, Mahabaleshwar, to evaluate the reaction of twenty-three wheat varieties against stem rust disease under controlled glasshouse conditions. Disease response was assessed using Peterson’s Scale, which classified the genotypes into six reaction categories based on their interaction with different stem rust pathotypes. Among the tested varieties, NIAW 1415 and NIAW 3624 exhibited a high level of resistance, showing effective defense against most stem rust pathotypes. Seven varieties viz., NIAW 4028, NIAW 34, NI 5643, NIAW 917, NI 917, Jay and NIAW 3170, demonstrated moderate resistance, suggesting their potential for stable performance under disease pressure. In contrast, five varieties viz., NI 345, NI 9947, Niphad-4, N 5439 and NIAW 301 were highly susceptible, indicating their vulnerability to stem rust epidemics. The remaining nine varieties displayed mixed reactions, with varying susceptibility across stem rust pathotypes. Overall, the findings emphasize the importance of promoting resistant and moderately resistant varieties for cultivation and highlight their potential utility in breeding programs aimed at developing new stem rust resistant wheat varieties.