Understanding the Influence of Microbial Sources and Time on the Developing Creeping Bentgrass Microbiome

Title of Thesis: UNDERSTANDING THE INFLUENCE OF MICROBIAL SOURCES AND TIME ON THE DEVELOPING CREEPING BENTGRASS MICROBIOME Joseph Ryan Doherty, Master of Science, 2018 Thesis Directed by: Assistant Professor, Dr. Joseph A. Roberts Plant Science and Landscape Architecture Microbial communities are intimately intertwined with many processes affecting the health of plants. There is increasing interest in utilizing microbial communities to increase plant health while reducing management inputs. To that end, bacterial and fungal communities associated with creeping bentgrass were evaluated using nextgeneration sequencing technologies. Evaluating the impact of resident seed and soil microbial communities revealed introductions of microbes from the seed despite a strong influence from the soil. Observing long-term population dynamics revealed no shifts in fungal diversity over six months, while bacterial diversity increased from emergence to two months post-emergence. Across both studies taxonomic profiling revealed that bacterial and fungal communities were consistently dominated by just a few groups. In both studies, ordination analyses revealed clustering of samples by sampling time. These results show that changes in the microbiome are driven by rare species, and that the turfgrass microbiome is resilient to change over time. UNDERSTANDING THE INFLUENCE OF MICROBIAL SOURCES AND TIME ON THE DEVELOPING CREEPING BENTGRASS MICROBIOME