PLANT GROWTH PROMOTING BACTERIA FROM GARLIC SOWED AT CURITIBANOS MICRO-REGION - SANTA CATARINA – BRAZIL

Abstract

Garlic has great economic and social importance for the region of Curitibanos (SC). However, a number of factors has hindered production. One of these factors is the high cost of fertilizers, especially the nitrogenous ones, an element of which the crop is highly demanding. To reduce the impacts, the use of PGPR (Plant Growth Promoting
Rhizobacteria), especially fluorescent Pseudomonas to induce plant development and their production has been widely studied. However, little is known about these microorganisms and garlic. Fluorescent Pseudomonas were isolated from rhizosphere of garlic cultivated in soil of the Curitibanos region (SC). Twenty-three isolates were phenotypical and genotypically analyzed. The phosphate solubiliziation, IAA (Indole Acetic Acid) production and Biological Nitrogen Fixation (BNF) in vitro, besides the effect on plant under controlled conditions were evaluated.
The phenotypic characteristics matched to those described for the group of fluorescent Pseudomonas. Fifty two percent of isolates solubilized Ca3(PO4)2, 69% presented FBN and 72% produced IAA. Genetically, all the isolates belonged to the genus Pseudomonas and resembled to Pseudomonas kribbensis, P. azotoformans or P. baetica. The strain CBSAL02 induced significant increase at fourth leaf size, having high correlation to the bulbification, suggesting its potential as a growth promoter and, consequently, production.