*Charu.sharma@icar.gov.in

Wheat (Triticum aestivum L.) is the second most important food crop globally, supports food security for millions. The sustained limitations on global wheat production persist due to the onset of various biotic and abiotic factors. Rust, caused by three distinct species of fungal genus Puccinia, stands as a significant biotic threat. Concurrently, increasing prevalence of salinity on a global scale emerges as a significant abiotic stressor, resulting in decreased wheat production across key wheat-growing regions worldwide.

In this piece of work, 41 salt-tolerant wheat lines were screened for rust resistance at seedling as well adult plant stages. The presence of rust resistance genes in these varieties were evaluated using gene matching technique in seedling stage (SRT) and through robust molecular markers linked to resistance gene as well as these lines were also screened for adult plant stage. The molecular studies confirmed presence of Yr2 gene in twenty three lines and gene Yr9 in four wheat varieties in association with Sr31 through SRT and molecular markers.

The presence of Lr24/Sr24 genes was identified in HD 2851 and KRL 2029 wheat genotypes and four wheat lines (KRL 283, KRL 2013, KRL 2017, and KRL 2029) were found to carry the Lr26 gene. With the exception of KRL2013, none of the wheat lines displayed absolute resistance to all Pst races used in this study. Additionally, Lr13 gene was found in a maximum of twenty-four wheat lines, with varying reaction responses to different leaf rust pathotypes.

The stem rust resistance gene Sr11 was identified in twelve wheat genotypes followed by Sr28, in ten wheat genotypes and Sr31 found in three wheat lines. Sr24 showed resistance towards all tested Pgt races, postulated in two wheat varieties HD 2851 and KRL 2029. Lr68 an effective race non-specific APR gene identified in fifteen wheat lines with the help of CsGs-STS marker.

Presence of Yr9/Lr26/Sr31 was confirmed using the SCSS30.2 marker, which produced a distinct 550bp band in five wheat genotypes. Although many salt-tolerant wheat lines were susceptible to yellow rust during the seedling stage, a few lines showed APR during 2020 and 2021 despite their susceptibility at the seedling stage.

Three lines (KRL 213, KRL219 and KRL 238) showed complete resistance in adult plant stage for leaf rust. The research yielded valuable scientific knowledge about the genetic foundation of rust resistance in salt-tolerant wheat varieties, enhancing our comprehension of wheat breeding approaches aimed at combating rust resistance.