Award Category

Natural Sciences and Mathematics

Publication Date



Nearly all plants share an asymptomatic symbiosis with many different kinds of endophytes: fungi and bacteria that exist within the plants. Despite their pervasiveness, much remains a mystery surrounding why these relationships exist. It is known that in certain circumstances the endophytes provide pathogen resistance for host plants. The purpose of this study was to identify certain factors that affect endophyte diversity. We chose to measure specific leaf area and canopy cover while collecting leaves from Rhododendron macrophyllum and Acer macrophyllum. These were chosen to represent low and high SLA. We predicted that leaves with low SLA will have fewer morphospecies due to more investment in leaf structure, thus having more built-in defenses. Sections of these leaves were plated on a mycelium medium to watch for growth. Endophytes were morphotyped by size, shape, and color. As predicted, Maple leaves showed 23% greater endophyte richness than Rhododendrons. Assuming a beneficial symbiotic relationship, it might be the possible that certain plants with a greater investment in leaf structure are not as reliant on endophyte protection. Canopy cover was not shown to have a significant affect on endophyte diversity and it was the same across leaf-types. To further address this issue, more plants would be needed to get a broader spectrum of SLA values. Further studies should aim at identifying if the endophytes are providing their hosts benefits and what those might be.

Faculty Advisor

Stacey Weiss


Biology 211: Ecology