Altered rhizosphere microbiome composition associated with B-subgenome cultivars of diploid and triploid banana plants

Plant genetic variation affects root phenotype and exudate composition, making it a pivotal factor in host-specific rhizosphere effects. Here we compare the rhizosphere microbiome of banana (Musa spp.) diploid cultivars (AA and BB), triploid cultivars derived from genome hybridizations into autotriploid cultivars (AAA), and various allotriploid cultivars (AAB and ABB) grown under field conditions to assess the influence of genome and subgenome type on the rhizosphere microbial community. Our study revealed that rhizosphere microbiomes of banana plants are significantly affected by banana genome type, presence/absence of the B-subgenome, and cultivar. Moreover, host selection strength in the assembly of the rhizosphere microbiome (i.e. rhizosphere effect) of B-subgenome-bearing banana was significantly greater than that of A-subgenome cultivars, and their rhizosphere microbial networks differed in hub membership, clustering, and node centrality measures. Thus, banana plants assemble different microbiomes in the rhizosphere according to their subgenome type. These results lay the groundwork for linking plant functional genomics and rhizosphere microbiome assembly.