Site and Clone Effects on the Potato Root-Associated Core Microbiome and its Relationship to Tuber Yield and Nutrients

The aim of this study was to describe the variability in the root-associated bacterial community due to location and clone, and to determine whether an underlying core bacterial community exists that might benefit the quality of the potato crop. Root-associated bacterial communities from one growing season were examined with 454 sequencing. Variance analysis using perMANOVA attributed 45.4 % and 24.1 % of the community variability to site and clone effects, respectively. A total of 123 bacterial operational taxonomic units were correlated with tuber yield and/or tuber nutrient content, a majority belong to the order Rhizobiales. Rhizobiales bacteria are recognized contributors to crop nitrogen needs for many legumes; however, no known symbiotic relationship between potato roots and nitrogen fixing bacteria exists. Within the Rhizobiales order, the genus Devosia is a major contributor to both the presence/absence core bacteriome and the sparse partial least squares core bacteriome, thus further exploration into this unknown relationship is warranted.