Correlations Among Grain Mold Severity, Seed Weight, and Germination Rate of Sorghum Association Panel Lines Inoculated With Alternaria alternata, Fusarium thapsinum , and Curvularia lunata

The sorghum association panel was evaluated for grain mold severity, seed weight, and germination rate. The 377 accessions were inoculated with Alternaria alternata alone, a mixture of A. alternata, Fusarium thapsinum, and Curvularia lunata, and untreated water-sprayed control during 2010, 2013-2015 growing seasons at the Texas AgriLife Research Farm, Burleson County, Texas. Each accession was evaluated at least twice. Across accessions, Spearman’s rank correlation was performed for non-parametric correlation analysis for grain mold severity, seed weight, and germination rate. There were significant negative correlations between grain mold severity with seed weight and germination rate for the individual treatment and when combined. A significant positive correlation between seed weight and germination rate was observed. The results indicated that higher grain mold severity reduces both sorghum seed weight and germination rate whether deliberately inoculated with fungal pathogens or naturally infected. It can be argued that correlations from this study were more robust due to a large number of accessions from all major sorghum races used and may represent the true association among the three parameters for this pathosystem. Thus, the use of grain mold-resistant lines, resulting in sound seeds and higher germination rates is recommended.