Response to Anthracnose and Germination Rate of Colletotrichum Sublineola Acervuli of Greenhouse-Grown Sorghum

Colletotrichum sublineola, the causal agent of sorghum anthracnose, infects all above ground parts of the crop. The most pronounced phase of the disease is its foliar phase. In this study, 10 sorghum lines with checks were evaluated in the greenhouse for resistance against C. sublineola. Acervuli germination rate within infected leaves was also recorded. All the 10 sorghum lines along with checks BTX623, TAM428, and PI609251 were susceptible and as expected, SC748 was resistant. Variation among the lines for acervuli germination rate was observed; TAM428 and 1110248 recorded the highest percentage (98.3%) while PI609251 exhibited the lowest rate of acervuli germination (33.3%). Conidia produced from germinating acervuli are critical to the distribution and spread of the disease. However, conidia produced within the acervuli do not usually germinate due to the presence of self-inhibitor compounds. Thus, these self-inhibitors that may occur in the acervuli could explain the difference in levels of susceptibility among sorghum germplasm.