Thu, Aug 18, 2022: 5:00 PM-6:30 PM
ESA Exhibit Hall
Background/Question/Methods: Fungi are major drivers of tropical forest dynamics. Endophytes are especially abundant and diverse in these ecosystems, where they can influence plant fitness by stimulating growth, suppressing diseases, promoting stress tolerance/resistance, mobilizing nutrients, etc. Much attention is now being paid to understanding the interactions and relationship between endophytes, host traits, and the environment, which is constantly exposed to factors that can affect the structure and composition of colonizing species. We seek to understand the effect of location, different developmental stages, and tissue type on community composition and diversity of endophytes spanning a range of tropical plant species. We hypothesize that endophyte communities are affected by all these factors, so changes in composition are expected to be observed. The sampling took place in two old-growth natural forests, in Golfito and Guanacaste, Costa Rica, where leaves and sapwood from plants belonging to the Rubiaceae family were collected and processed. Fungal diversity was assessed by metabarcoding using the ITS2 nrDNA region fITS7 and ITS4, library sequencing was completed by Ion Torrent technology, and the data was analyzed in RStudio.
Results/Conclusions: Most ASVs identified belong primarily to the Ascomycota phylum. Botryosphaeriales and Glomerellales were the orders contributing the most species to the endophytic assemblages. The total colonization frequency and species richness of endophytic fungi were statistically higher in Golfito. No statistically significant differences were observed between mature and juvenile tissues and, in general, leaves presented richer and more diverse assemblages than sapwood. Since plant tissues are exposed to different environments in time and space our results could be influenced by structural and chemical properties that change through ontogeny. In conclusion, it is crucial to continue the efforts on understanding the degree to which apparent patterns of host colonization are dictated by the host, the endophyte, or other ecological mechanisms.
Results/Conclusions: Most ASVs identified belong primarily to the Ascomycota phylum. Botryosphaeriales and Glomerellales were the orders contributing the most species to the endophytic assemblages. The total colonization frequency and species richness of endophytic fungi were statistically higher in Golfito. No statistically significant differences were observed between mature and juvenile tissues and, in general, leaves presented richer and more diverse assemblages than sapwood. Since plant tissues are exposed to different environments in time and space our results could be influenced by structural and chemical properties that change through ontogeny. In conclusion, it is crucial to continue the efforts on understanding the degree to which apparent patterns of host colonization are dictated by the host, the endophyte, or other ecological mechanisms.