Abstract Presented at Plant Biology 2019

Kent F. McCue¹, Priyanka Mehta², Norma Morella³, Gerard Lazo¹, Britt Koskella³ and Rajnish Khanna²

¹USDA-ARS, 800 Buchanan Street, Albany, CA

²i-Cultiver, Inc., 404 Clipper Cove Way, San Francisco, CA

³Department of Integrative Biology, University of California, Berkeley, CA

In previous experiments, Berg and Koskella (Current Biology 28: 2487, 2018) have shown that phyllosphere (above ground) microbiota of tomato provide protection against plant pathogens in nutrient- and dose-dependent manner. We have investigated whether the microbes from field-grown potatoes changes during the growing season and whether there is an effect of  fertilizer regime on the abundance and diversity of the microbiome in the soil, rhizosphere, endosphere and phyllosphere, and on the yield of potato tubers. Changes in microbiome associated with improved potato yield is expectant as a result of improved nutrient assimilation and abiotic and biotic stress resistance. We have extended the experiments to compare the effects both of standard Nitrogen fertilization and Azomite^® volcanic ash fertilizer (AZOMITE soil products, LLC). We have conducted 16S rRNA gene sequencing to determine microbiome dynamics between soil, rhizosphere, root endosphere and phyllosphere. These results will be used to analyze any functionally significant correlations between the different microbiomes during the growing season, and plant assimilation of available nutrients from soils treated with or without Azomite^® volcanic ash fertilizer, potentially providing novel methodologies to increase yield in agricultural context.