PS 3-43 - MOVED TO THURS #94 - Fungal endophytes of Khaya senegalensis: An analysis of harvest triggered micro-succession

Abstract: Fungal endophytes are known to enhance the capability of plants to tolerate different types of stress and improve the resistance of plants to insects. However, our understanding of how chronic anthropogenic disturbance could drive endophyte community composition is limited, particularly for tropical systems. This study assessed whether harvesting a tree by local people causes a significant shift in the fungal endophyte community within its leaves. We hypothesized; (1) that in the face of harvest driven disturbance, species diversity of fungal leaf endophyte communities of Khaya senegalensis would decrease, and (2) Arthropod driven interactions like gall presence and weaver ant presence would be negatively correlated with fungal leaf endophyte species diversity. Additionally, the identity and diversity of Khaya senegalensis (Meliaceae) endophytes is unknown, so (3) we aimed to capture the true fungal leaf endophyte diversity of Khaya Senegalensis for the first time. To test these hypotheses, we selected four populations (two harvested and two unharvested) of Khaya senegalensis (Meliaceae), a harvested tree by local pastoralists across Benin in West Africa. In each population, we randomly collected three leaves on up to 30 Khaya senegalensis trees sampled across 1ha permanent plots. We cultured leaf fragments from these leaves and isolated culturable endophytes. Cultures were grouped morphologically by color, texture and production of sclerotia or fruiting-body primordia and were identified to species by Sanger DNA sequencing.

We used these data to build a generalized linear model to test for significant interactions between disturbance, arthropod prevalence and endophyte diversity. We found significant effects of debarking, years since pruning, weaver on endophytes community composition and diversity. These results are in support of our hypothesis that anthropogenic disturbance such as leaf and bark harvest directly affect fungal morphotype species diversity. For our second hypothesis, we found a negative correlation between weaver ant presence and leaf fungal endophyte species diversity, but no significant change in endophyte diversity with gall presence. Lastly, this study was the first to asses and capture fungal endophytes of Khaya senegalensis, and while it focused solely on the fungal leaf endophytes, we believe it was an important first step in furthering our understanding of endophytes of Khaya and adding to the need for ecological studies in the region.