Plant growth-promoting yeasts
yeas, rice, bean
Yeasts are single-celled fungi that can be found naturally in the rhizosphere and in the phyllosphere of plants. Some species are able to participate in different important biotechnological processes, such as : biological control of fungi for their ability to produce killer toxins, production of siderophores and other effects used as promoters of plant growth. This work aimed to evaluate the action of promoting the growth of plants by yeast. Results of natural environments and yeast collections. Roots of rice and beans were isolated from 14 yeast lines, as they were evaluated with in vitro germination tests, experiments in a greenhouse and field. Users with growth promotion behavior were affected by the classic taxonomy and by the sequencing of the transcribed internal spacer region (ITS) and the D1 / D2 domains of the large subunit of the rRNA gene. Mechanisms of action to promote growth, production of killer toxins, volatile compounds, indolacetic acid (AIA), presence of 1-aminocyclopropane-1-carboxylate (ACC) deaminase enzyme, solubilization of phosphates, zinc, aluminum and siderophores, were tested. The evaluation of antagonism and pathogens in solid culture media. The results obtained in the selection of growth-promoting yeasts indicated three species of yeasts with good results (Torulaspora indica, Candida intermedia and Spatasfora suhi), provide greater root growth in 23% and 18% in the aerial part and 25% in the total biomass at the end This comparison is relevant, considering that the additional development in the root system helps to improve the conditions of absorption of nutrients and other plant compounds for the development of the growth cycle. achieved positive results for any test of production of volatile compounds and ACC and aluminum solubilization, and all yeasts isolated from plant roots were able to produce killer activity, AIA and solubilize phosphates and zinc oxide or that contribute to the promotion of plant growth.