Simon Morvan

The rhizosphere microbiota of wild blueberries.

Simon Morvan, Mohamed Hijri, Maxime Paré

Canada is the largest producer of wild blueberries in the world. The crops are grown in boreal regions using two species belonging to the Ericaceae family: Vaccinium angustifolium, known to be very productive but more sensitive, and Vaccinium myrtilloides, hardy and more resistant. The main edaphic properties of ericaceous culture are high carbon to nitrogen ratio and low pH. The contribution of ericoid mycorrhizal fungi is essential as they increase the nitrogen and phosphate supply, by accessing non-assimilable sources by the plants. Field studies on microbial diversity associated with wild blueberry roots, especially ericoid mycorrhizal fungi, remain fragmentary. This PhD project will focus on three main objectives: 1.    Characterize the fungal and bacterial communities of the wild blueberry root environment. We’ll also compare the communities of the two wild blueberry species. 2.    Identify bacterial and fungal species correlated to productivity in blueberries. 3.    On a more agronomic point of view, we’ll focus on assessing the impact of thermal pruning on the microbial communities. As of now, nine plots with different yields were selected within three commercial blueberry fields in the Lac St-Jean region of Quebec. Five rhizospheric soil samples of V. angustifolium were collected per plot, for a total of 45 samples. We proceeded to the DNA extraction and amplification of 16S and ITS regions. Sequencing was done using Illumina MiSeq and DADA2 was used for bio-informatics analyses. 3,300 amplicon sequence variants (≈OTU) were obtained for ITS, and 10,111 for 16S.