Exogenous microbial consortia modulate rhizosphere microbiome and yield of grafted tomato grown in the mediterranean greenhouse
摘要
The adoption of sustainable agricultural practices for intensive horticultural production could determine less damage to the ecosystem is a fundamental need increasing worldwide. In this trial the effect of two commercial microbial consortia, applied on two hybrid rootstocks of tomato grafted by two scions, were evaluated both on yield components and on the compositions of the rhizosphere microbiome. The rhizosphere was collected from each grafting combination, in both treated and non-treated plots. Microbiome DNA extracted was then sequenced by amplifying two specific regions ITS1-1F for fungus and 16SV34 for bacteria.
ResultsAt the morphological level, the effect of microbial consortia application on the total production and yield showed to be highly dependent on the grafting combination, yield increased by 9.1, 10.3 and 12.6% in treated plots of Auto S2, R1/S1 and R1/S2 respectively but registered a reduction of 22.4% in NG.S2 and 9.3% in R2/S2 plots. The metagenomic sequencing revealed that fungal community composition was significantly influenced by both grafting combinations and microbial treatments (especially on the relative abundance of major phyla; Ascomycota and Basidiomycota), whereas bacterial communities exhibited stronger shifts in response to microbial consortia application than to grafting combinations. Correlation analysis between the rhizosphere microbial taxa, yield, and root weight highlighted significant associations supporting the potential of combined use of these practices. Notably, although the inoculated microorganisms were detected at low abundance or were not detectable in treated soils, pronounced shifts in the overall microbiome structure were observed, suggesting indirect yet significant ecological effects of the consortia.
ConclusionThis study demonstrates that microbial consortia and grafting synergistically enhance tomato productivity and modulate rhizosphere microbial communities in the monoculture degraded soil under intensive Mediterranean greenhouse conditions. These findings advance current understanding of plant genotype × microbial consortium interactions by demonstrating that microbial inoculant relevant effects are highly modulated by plant genotype and can indirectly restructure rhizosphere microbial assemblages, contributing to the development of more sustainable and resilient horticultural systems.