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 were examined at three sites over the course of three years.  Variance analysis using perMANOVA attributed 45%, 30%, and 10% of the community variability to year, site, and clone effects, respectively.  A total of 123 bacterial operational taxonomic units were correlated with tuber yield and/or tuber nutrient content; the majority of these 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, members of the genus Devosia are of particular interest for further studies, since they were common to the majority of the root samples and significantly positively correlated with tuber yield and nutrient contents.