Indirect Relationship between Herbivores as Mediated through Endophyte- Containing Plants

Student Author(s)

Miranda Ulmer

Faculty Mentor(s)

Dr. Thomas Bultman

Document Type


Event Date



Fungal endophytes are a key aspect to the defense mechanism of many grasses, and it is their production of alkaloids that has been shown to inhibit herbivory. Up until this point, studies of this kind have primarily been focused on the effect endophytes have upon herbivores. There is a whole breadth of knowledge still to be discovered pertaining to the reciprocal effect, that of the effect of the herbivore on the endophyte. Here, we tested if horse (Equus ferus caballus) saliva has an effect on alkaloid levels produced by endophytes within Tall fescue (Schedonorus arundinaceus). In order to determine the biological activity of our treatment groups, a bioassay was performed, using aphids (Rhopalosiphum padi L), and a loline analysis was carried out as well. We found that the infected plants supported fewer aphids than uninfected plants. Saliva caused an increase in aphid survival for the uninfected plants, and the opposite was true for infected plants. To further our results, we intend to perform an ergot chemical assay. Analysis of these results will hopefully give us more insight into the insectfungus interaction.

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