Jean-Baptise Floc'h

IRBV- Université de Montréal
Core-microbiome of the rhizosphere of canola variates through time.

Jean-Baptiste Floc’h, Chantal Hamel, Newton Lupwayi, Marc St-Arnaud, Neil Harker

The micro-organisms that live in the close environment of plants form the plant microbiome. It has a large influence on plant development and growth. Some of it could be of great importance for the plant health and are always present with the plant. It is the core microbiome : a subset of the microbes that are always present in the close environment of a plant as formalized by Vandenkoornhuyse et al. (2015). However, most of the recent studies consist in analysing a snapshot of the microbial communities. But microbial communities are subject to variation across time. Thus, it is necessary to decipher the structure and the dynamics of the core-microbiome to optimize the efficiency of plant production. As canola is a plant of economic interest in Canada and provide simpler microbial communities in its rhizosphere, we used it as a model plant to study rhizosphere core-microbiome. We tested the hypothesis that canola has a core microbiome that variate through time and crop-rotations. To do so, we conducted an assay in 2013 and 2016: we used the canola phase of five cropping system, from the less to the most diversified, in an existing long-term (6 years) field experiment. It has a randomized complete block design with four blocks and is replicated at three locations: Lacombe, Lethbridge and Scott. Our results show that crop diversification does not influence the core-microbiome but that core-microbiome changed between 2013 and 2016. Our results are presented as a basis for a redefinition of the core-microbiome concept.