Isolamento e caracterização de bactérias promotoras de crescimento vegetal de lavouras experimentais de arroz sob diferentes níveis de fertilização

AUTOR(ES)

Pedro Beschoren da Costa

FONTE

IBICT - Instituto Brasileiro de Informação em Ciência e Tecnologia

DATA DE PUBLICAÇÃO

2012

RESUMO

Chemical fertilization is widely used for increased crop productivity, but its production and use lead to serious environmental damage. To reduce the use of fertilizers, one can make use of plant growth promoting rhizobacteria (PGPR), which are plant-associated bacteria that increase plant health, size and yield through various mechanisms. PGPR effectiveness is known to fluctuate with environmental conditions; however, studies regarding the effect of chemical fertilization on plant growth promoting (PGP) traits of PGPR are scarce. In this work, the effects of long-term fertilization on the diazotrophic diversity, occurrence and expression levels of PGP traits from 190 bacterial strains isolated from rhizospheric soil and roots of rice were analyzed. We found that fertilization had a limited effect on diversity but had a major effect on phosphate solubilization and indolic compounds (IC) production abilities. We propose that plants select bacteria that present good phosphate solubilization ability for intimate root association in lieu of good IC production under nutrient-poor conditions and select good IC producers in lieu of good phosphate solubilizers under nutrient-moderate conditions. In nutrient-rich conditions, this selection preference seems to be deactivated. After testing seven selected isolates for effective in vivo plant growth promotion in greenhouse conditions, our predictions were tested in the field. We found that good phosphate solubilizers only promoted growth at nutrient-poor conditions and that good IC producers only promoted growth at nutrient-moderate conditions. In nutrient-rich conditions, phosphate solubilization and IC production were not key factors to promote plant growth. These findings may be used for directed PGPR prospection and anticipated PGPR candidate selection, according to plant needs and farmer interests.

ASSUNTO(S)

bactérias fertilização arroz

Documentos Relacionados

• Isolamento e seleção de bactérias promotoras de crescimento vegetal associadas a cana-de-açúcar
• Isolamento e caracterização de duas bactérias promotoras de crescimento vegetal do rizoplano de uma leguminosa (Lupinus albescens) de solo arenoso
• INOCULAÇÃO E ISOLAMENTO DE BACTÉRIAS PROMOTORAS DO CRESCIMENTO VEGETAL EM MILHO CULTIVADO EM VITÓRIA DA CONQUISTA, BAHIA
• Isolamento e caracterização de linhagens de Bacillus e Paenibacillus promotores de crescimento vegetal em lavouras de arroz e trigo do Rio Grande do Sul
• Caracterização bioquímica e molecular de isolados de bactérias promotoras do crescimento vegetal associadas ao girasso (Helianthus annuus)