Fungal and bacterial population from spent mushroom substrate used to cultivate tomato plants

Abstract

The production of tomato seedlings is conducted on commercial substrates with adequate properties for the good formation of the aerial part and root. The Spent Mushroom Substrate, or SMS, presents advantages over commercial substrates regarding the quality of the vegetable seedlings, which may be provided by the presence of a rich microbiota, bringing higher balance and competition with pathogenic microorganisms, in addition to the biological control of pathogens and nematodes. It is important to know the microbiota present in this material and its relation to the plant, in order for this association to occur in the best manner possible. This work had the objective of identifying the microbiota present in the rhizosphere of tomato seedlings produced in SMS of Agaricus subrufescens and Agaricus bisporus mushrooms, added or not with commercial substrate. The microbiota was analyzed by DGGE and the representative samples were sequenced in order to identify the species. Among the eukaryotes, the Chaetomium globosum, Arthrobotrys amerospora species were predominant in the A. subrufescens SMS, and Geastrum floriforme, Chrysosporium chiropterum, Pleurotus sp., and Trichosporon sp. in the A. bisporus SMS. Prokaryotes are the most diverse group, suggesting a large number of species not yet classified or which sequences are not yet available.