Arbuscular mycorrhizae and two Patagonian yeasts co-inoculation effects on tomato production under greenhouse conditions.

N. ROBREDO; FONTENLA S; BOENEL M; MESTRE M. C.

Workshop; II International Symposium, Mycorrhizal Symbiosis in South America; 2019

The use of microorganisms is a valued tool in agricultural production to expand productive borders and minimize the use of fertilizers. Technological investment is also a challenges that regional and national production needs to address. In recent years, in-vitro physiological characteristics associated with plant growth promotion has been described in yeasts. The tomato is one of themost important horticultural crops in Argentina. The aim of this work was to evaluate the development of tomato plants (Lycopersicum esculentum) inoculated with two Patagonian native yeasts and the arbuscular mycorrhizal fungus Funneliformis mosseae (FM) in a pot trial inside the greenhouse. The yeast isolates were selected for their ability to produce auxin-like compounds, siderophores and solubilize phosphate. Germinated seeds of tomato weretransplanted to tray containing sterile commercial seedbed substrate, with or without FM inoculum. After the appearance of the first true leaves, the seedlings were inoculated with a suspension of yeasts. Forty days old seedlings roots were collected to evaluate mycorrhizal colonization and they were transplanted into pots with perlite, peat and non-sterile soil from thesurrounding areas. Plant growth and symbionts behaviour were evaluated at the end of growing season. Yeast inoculation showed no significant differences on growth or production variables. Plants inoculated with FM showed significant increase of stem length and dry aerial biomass, and also in production variables: higher proportion of plants with fruit, greater number and weight of fruits. Seedlings at the time of transplant showed no mycorrhizal colonization; while at harvest time, the plants reached 28-50% of AM colonization. A significant increase was also observed by the inoculation of FM and the yeast strain identified as Saccharomyces eubayanus. For the production of tomato, simulating normal greenhouse production, the inclusion of FM symbionts showed beneficial effects on growth and productive variables. The inclusion of S. eubayanus a soil yeast, which seems to be a colonization-helper when used together with F. mossae inoculum. The co-inoculation of both microorganisms could be a suitable strategy to improve production in the region.