Characterization and genetic diversity of Curvularia lunata isolates associated with sorghum grains mold in Egypt.

Sorghum bicolor, an important crop in arid and semi-arid areas, faces significant biotic stressors,particularly grain mold caused by fungal infections. Curvularia lunata emerged as a prominent pathogenin sorghum leaf spot and grain mold, significantly impacting grain quality and yield. This study aimed toisolate and characterize C. lunata strains from sorghum grain obtained from Egyptian markets. Tenisolates were found, and tests on sorghum cultivar Giza 15 showed a wide range of virulence, withdisease ratings ranging from 22.67% to 66.68%. Morphological identification and phylogeneticinvestigation verified the isolates' identity as C. lunata, with RAPD-analysis revealing the geneticdifferences between isolates. Phylogenetic analysis divided the isolates into two major groups, withconsiderable genetic similarity within each group. However, some isolates revealed significant geneticdivergence. The RAPD profiling revealed 38 DNA fragments, 93.05% of which were polymorphic,showing that the isolates studied had a high level of genetic diversity. This diversity demonstrates thepathogen's adaptability, which may be connected to pathogenic potential in various conditions. Thefindings provide critical insights for breeding resistant sorghum varieties and underscore the need forcomprehensive management strategies to mitigate grain mold's impact on sorghum production.