Elucidating the Influence of Seeds and Soil on the Developing Creeping Bentgrass Microbiome.

The plant microbiome encompasses all microbial groups populating both the rhizo and phyllosphere. Research on microbiomes has increased in recent years, but our knowledge of microbial communities in turfgrasses is limited.  The objective of this research is to investigate the impact resident seed and soil microbiota have on the development of the creeping bentgrass (Agrostis stolonifera cv. “007”) microbiome over time.  Creeping bentgrass was established in a modified laminar flow hood to create a sterile-air growing environment.  Seeds were planted in 50 mL conical tubes of either sterilized or non-sterilized soil (85% sand 15% peat).  Conical tubes of sterilized soils remained unplanted to serve as a control.  Treatment replicates were arranged in a randomized complete block design and all received sterilized half-strength Hoagland’s solution 2X weekly in addition to sterile dH₂O applied daily.  Samples of above and below ground tissue were taken at 2, 4, and 6 weeks post emergence.  Total available DNA from plant tissues were extracted using Invitrogen’s EasyDNA kit and soil microbial DNA was extracted with the MoBio Power Soil DNA kit.  Following extraction, DNA was barcoded and pooled, prior to analysis on the Illumina MiSeq platform.  Metagenomic data was analyzed using the default pathway in QIIME and statistical analysis performed using the Vegan package in R.  Turf planted in non-sterile soil emerged sooner and exhibited more vigor when compared to turf established in sterile soil.  In addition, yield from metagenomic DNA extractions increased as turf matured.  Moving forward long-term studies will be useful in assessing seasonal fluxes in microbiome populations.