Alterações morfo-anatômicas induzidas por bioestimulantes promotores de crescimento em mudas de açaizeiro.

Abstract

The application of beneficial microorganisms to plant induces several morphoanatomic changes that are associated with growth promotion. The aim of this study was to evaluate the morphological and anatomical alterations by biostimulants in açaí seedlings (Euterpe oleracea Mart.). At five months age açaí seedlings were inoculated with Burkholderia pyrrocinia (BRM-32113), Bacillus subtilis (UFRA-92), Trichoderma asperellum (UFRA T-06, T-09, T-12 e T-52) and a control (uninoculated), with five repetition. All biostimulants induced favorable increase morphological and anatomical alterations for growth promotion in the evaluated seedlings. Seedlings inoculated with biostimulants presented higher height, stem diameter, number of leaves and robustness index. Anatomical changes in relation to control involve increased mesophyll, limb thickness, leaf vein thickness and width, as wel as the amount size of metaxylem vessel elements. Compared to the control, only the isolate BRM-32113 induced increase in root diameter, cortex and metaxylem cell diameter in the first order lateral roots, whereas in the secondary order lateral roots all isolates stimulated increases in the cortex diameter. The inoculation of biostimulants in açaí seedlings induced morphological and anatomical changes that may improve physiological performance and contribute the growt promotion.