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Anthracnose and grain mold are two of the most significant diseases of sorghum, a versatile crop that plays an important part in the daily lives of millions of inhabitants, especially in the drier tropical regions. The aim of this study was to determine the influence of four agronomic traits in selected sorghum germplasms on the two diseases using Spearman's ρ test to identify significant pairwise correlations. Both anthracnose and grain mold scores were significantly and negatively correlated with seed weight and germination rate. The grain mold infection score also demonstrated negative correlations with plant height (Spearman ρ = −0.61 and p-value = <0.0001) and panicle length (Spearman ρ = −0.27 and p-value = 0.0022). In this investigation, principal component analysis and clustering variables analysis revealed that seed weight and germination rate exhibited a directional alignment, suggesting a positive association. Similarly, panicle length and plant height clustered together, suggesting a shared variation pattern. Additionally, a support vector machine and random forest models effectively predicted the germination rate based on the studied traits, highlighting the potential of machine learning in understanding complex trait relationships in sorghum. This work provides insights into the relationship between agronomic traits and disease resistance, thus contributing to sorghum improvement efforts. [ABSTRACT FROM AUTHOR]

Sorghum (Sorghum bicolor L.) ranks fifth as the most crucial cereal crop globally, yet its seed morphology remains relatively unexplored. This study investigated seed morphology in sorghum based on 115 mini-core and 130 Senegalese germplasms. Eight seed morphology traits encompassing size, shape, and color parameters were assessed. Statistical analyses explored potential associations between these traits and resistance to three major sorghum diseases: anthracnose, head smut, and downy mildew. Furthermore, genome-wide association studies (GWAS) were conducted using phenotypic data from over 24,000 seeds and over 290,000 publicly available single nucleotide polymorphisms (SNPs) through the Genome Association and Prediction Integrated Tool (GAPIT) R package. Significant SNPs associated with various seed morphology traits were identified and mapped onto the reference sorghum genome to identify novel candidate defense genes. [ABSTRACT FROM AUTHOR]

Sporisorium reilianum causes head smut in sorghum. A total of 36 Senegalese sorghum accessions comprised of sorghum lines that have not been explored with response to pathotype 5 of S. reilianum were evaluated with 3 different treatments. First, seedling shoots were inoculated while still in soil with teliospores in agar, and then submerged under water at 4 days post inoculation. Signs of infection (noticeable spots) on the first leaf were observed up to 6 days post submergence. Second, seedlings at the same stage were inoculated by placing the teliospore impregnated agar around the stem in pots, moved to a greenhouse and grown to full panicle development stage. Third, seedings were inoculated via syringe inoculation in the greenhouse. Although soil inoculated seedlings grown in the greenhouse did not result in systemic infection as determined by lack of symptoms at panicle exsertion, 88.9% of tested cultivars showed systemic infections when syringe inoculated in the greenhouse. Inoculation of seedlings maintained under water led to broad range of noticeable spots that are assumed to be potential infection sites based on a previous study. In addition, seedling inoculation led to slightly upregulated expression of chitinase and PR10, genes that are associated with defense in aerial parts of plants. [ABSTRACT FROM AUTHOR]