*Corresponding and presenting author E-mail: vijayrana_2005@rediffmail.com

Major biotic constraints in wheat production are wheat rusts caused by Puccinia species. Of the three rusts i.e. (stripe leaf and stem); stripe rust caused by P. striiformis f. sp tritici (Pst) is the important disease in many wheat growing regions of the world. India witnessed an outbreak of this disease during last decade on the previously known susceptible varieties.

North Hill Zone of India is strategically important for safeguarding yield potential of the rest of the wheat producing zones, as it serves as a source of primary inoculums for stripe rust. Therefore, evaluation of the newly developed strains, mutants and local landraces to stripe rust is important before releasing cultivars and use as potential sources for resistance. Therefore, the purpose of this study was to identify stable sources of resistance to yellow rust in North Western Himalayan conditions of India.

Sixty-six germplasm lines, including mutant lines from mutation breeding programme of BARC, Trombay (India), high yielding varieties, advanced breeding lines and some local landraces were evaluated in six environments at the Rice & Wheat Research Centre, Malan for three consecutive years through 2019-2022 and at off season hotspot locations; HAREC, Kukumseri during Summer 2020 and Summer 2021, while at the ICAR- IIWBR, Regional Station, Dalang Maidan during 2022. These lines were also tested for seedling resistance against four prevalent yellow rust pathotypes (78S84, 110S84, 110S119, 238S119

Results of the multi-environment evaluation revealed that out of 66 experimental lines, the genotype TYRM 2 was found consistently free from the disease over the environments, where not even a single fleck of yellow rust was observed and therefore can be considered as highly resistant. This genotype was also found resistant to all the prevalent pathotypes of the yellow rust pathogen in seedling resistance test. ). PW 1908, FLW 16, Unnat PBW 550, which recorded low rAUDPC values (≤ 5) in all three seasons, were found to be slow rusting.

The other resistant genotypes identified on the basis of muti-environment evaluation were Unnat PBW 550, FLW 16, HS 562, PW1908, HPW 368, WH 1270, HTW 9, HPW 469, HIKK 05 and HI 8173. In overall testing, genotypes viz., TYRM 2, PW 1908 and FLW 16 were found superior for yellow rust resistance along with high grain yield potential. These genotypes can be used as potential donors for yellow rust resistance for diversifying the genetic basis of resistance of cultivars in rust prone zone.