Endophytic Fungi Can Affect Herbivorous Pest Resistance and Tolerance in Sorghum Bicolor

Plant-microbe associations can play a pivotal role in resistance against herbivorous insects in addition to promoting plant growth, and thus tolerance of herbivory. We examined the potential for beneficial symbiotic interactions between three endophytic fungi and Sorghum bicolor when applied as a seed inoculation treatment. Plants treated with these fungi were assessed for resistance against the invasive sugarcane aphid, Melanaphis sacchari, by quantifying aphid population growth over time. Plant growth enhancement and tolerance to pest herbivory were assessed by comparing plant growth in both the presence and absence of herbivore pressure among the different fungal inoculation treatments. Significant effects of fungal seed treatment on aphid performance and plant growth were observed, but the effects were not always consistent across replicate trials. Future work will focus on endophytic colonization and the effects of these fungal treatments on herbivores using different plant inoculation strategies.