Uses of Quenchers Methodology in the Management of Loose Smut Disease (Ustilago nuda) of Barley (Hordeum vulgare) through Seed Dressing and SRAP Markers Associated with Resistance in Some Egyptian Barley Genotypes

Barley production has been constrained by various factors, of which loose smut (Ustilago nuda) is the main biotic factor. Molecular and agronomical screening analyses were evaluated to study the similarity levels and marker assisted selection associated with resistance to loose smut among eight barley genotypes using sequence-related amplified polymorphism (SRAP). Agronomical parameters during two consecutive 2021 and 2022 seasons were studied to identify their reaction to loose smut. The results exhibited significant differences among all studied genotypes for all studied characters, and the highest mean values for all studied traits were detected in Giza 136 and Giza 137. Six SRAP selected primer combinations were amplified and gave 56 total fragments, where primer combination me1+em3 gave the highest polymorphism (100%) and the highest polymorphic information content of PIC was 0.96. The dendrogram of SRAP markers had clustered all studied genotypes into two main clusters. Cluster I includes all the resistance genotypes Giza 136, Giza 137, Giza 123, Giza 132, Giza 138 and Line 2. However, cluster II includes only Line 1 and Line 3 as susceptible genotypes. Thus, SRAP marker could be efficiently used to assess genetic variation among barley genotypes and useful for barley germplasm management in terms of biodiversity protection and design of new crosses for loose smut breeding programs, and seed dressings are commonly used to prevent infected seed from developing smutted heads. Some effective seed dressings include Triticonazole, Black seed oil and gamma rays 150, 200, 250 Gy. The tested fungicide was highly effective in controlling the disease and gave more than 99% disease control with high grain yield while nature product as black seed oil and utilizing radiation gamma ray 250 GY was the most effective. Utilizing radiation and natural ingredients to manage loose barley smut is economical.