There is a growing appreciation for the importance of the rhizosphere microbiome in determining nutrient use efficiency and crop yield. Various strains of fungi and bacteria are able to improve nutrient acquisition in plants by fixing N, mineralizing organic nutrients, solubilizing P, and sequestering Fe through siderophore production. The rhizosphere microbiome is shaped by a set of hierarchical and interacting drivers. The bulk soil community is shaped by edaphic factors. Rhizodeposition drives recruitment of the rhizosphere microbiome from the bulk soil source community (the soil metacommunity). This colonization is host-specific, and plant genotype can play a significant role in determining the composition of the rhizosphere microbiome. The functional capacity of the rhizosphere microbiome and the benefit conferred onto the host plant, as well as ecosystem services such as nutrient cycling and GHGe, vary with the composition of microbial assemblages. We expect that plant genotypes will differ in their ability to recruit microbial functional groups, and that the functional profile of the microbial community can be treated as a selectable plant phenotype and optimized through plant breeding. We used Illimina HiSeq sequencing to survey the rhizosphere of diverse maize genotypes to compare their capability to recruit microbial nitrogen cycling functional groups.
Results/Conclusions
Signifcantly different microbial communities were observed among ancestral, inbred, hybrid genotypes of maize. These major groups of host plant also differed signifcantly in their recriutment of nitrogen cycling functional groups. Distinct assemblages of denitrifiers and diazotrophs were observed among maize genotypes, suggesting that there is genetic capacity to optimize recruitment of N cycling functional groups, and improve the sustainability of this major crop group.