Genome-Wide Screening of Broad-Spectrum Resistance to Leaf Rust (Puccinia triticina Eriks) in Spring Wheat (Triticum aestivum L.)

Abstract

Wheat leaf rust (LR) causes significant yield losses worldwide. In Egypt, resistant cultivars began to lose their efficiency in leaf rust resistance. Therefore, a diverse spring wheat panel was evaluated at the seedling stage to identify new sources of broad-spectrum seedling resistance against the Egyptian Puccinia triticina (Pt) races. In three different experiments, seedling evaluation was done using Pt spores collected from different fields and growing seasons. Highly significant differences were found among experiments confirming the presence of different races population in each experiment. Highly significant differences were found among the tested genotypes confirming the ability to select superior genotypes. Genome-wide association study (GWAS) was conducted for each experiment and a set of 87 markers located within 48 gene models were identified. The identified gene models were associated with disease resistance in wheat. Five gene models were identified to resist all Pt races in at least two experiments and could be identified as stable genes under Egyptian conditions. Ten genotypes from five different countries were stable against all the tested Pt races but showed different degrees of resistance.

Unlocking the genetic control of spring wheat kernel traits under normal and heavy metals stress conditions

“…However, due to the presence of few cases where MLM was identified as a better model, we can conclude that it is always better to test all available GWAS models to detect the best model that fits into the data. Similar results were reported in other studies (Mourad et al 2022).…”

“…The recent studied population is a highly diverse one that collected from 14 different countries around the world. It was reported as a perfect material in identifying marker allele associated with different biotic and abiotic stresses (Joshi and Nayak 2010;Abou-Zeid and Mourad 2021;Ahmed et al 2021;Mourad et al 2021aMourad et al , 2022Hasseb et al 2022). Furthermore, high genetic variation with high degree of heritability was found among the tested genotypes in kernel traits under all the studied conditions (Mourad et al 2021b).…”

“…Therefore, GWAS was conducted for each condition separately. The presence of population structure in the recent tested population was reported previously and three subpopulations were detected (Mourad et al 2020(Mourad et al , 2022Abou-Zeid and Mourad 2021). Therefore, PCA and Kin were included in the tested models to correct the effect of population structure.…”