Fruitful Foundations: Novel Insights into Community Composition and Succession in the Hydroponic Strawberry Rhizosphere Microbiome

Abstract

As the global population increases, the productivity of food production systems must also increase. In Canada, strawberry production has declined significantly over several years, highlighting the need for strategies that increase fruit yield and production stability. Microbial inoculants, especially when used in controlled environment agriculture (CEA), present a possible strategy for increasing strawberry yields by leveraging naturally occurring symbiotic relationships between rhizosphere microorganisms and host plants. However, research into developing an effective microbial inoculant for hydroponic strawberries has been unfruitful, in part because the hydroponic strawberry rhizosphere is poorly understood.

In this study, soil samples were added to hydroponic strawberries as an initial source of microbial diversity to influence community assembly. The objectives of this research were to describe community composition, succession, and persistence of bacteria, fungi, and oomycetes within the hydroponic strawberry rhizosphere using 16S and ITS ribosomal RNA (rRNA) amplicon sequencing. Microbial succession was evident, with numerous differentially abundant taxa between initial and final timepoints. However, no microbial taxa were significantly associated with changes in yield. This study also identifies a candidate core microbiome for hydroponic strawberries. The commercial implications of these findings are discussed. Overall, these findings form a foundational understanding of the hydroponic strawberry rhizomicrobiome, and suggest several novel strategies for development of an effective inoculant for hydroponic strawberry production.