Screening of rhizobacteria isolated from maize (Zea mays L.) in Rio Grande do Sul State (South Brazil) and analysis of their potential to improve plant growth

• Published in: Applied soil ecology : a section of Agriculture, ecosystems & environment Vol. 63; pp. 15 - 22
• Main Authors: Arruda, Letícia, Beneduzi, Anelise, Martins, Adriana, Lisboa, Bruno, Lopes, Cristiane, Bertolo, Fernanda, Passaglia, Luciane Maria P., Vargas, Luciano K.
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 01.01.2013; Elsevier
• Subjects: Achromobacter; Agronomy. Soil science and plant productions; Arthrobacter; Bacterial diversity; Biochemistry and biology; Biological and medical sciences; Burkholderia; Chemical, physicochemical, biochemical and biological properties; corn; corn soils; cultivars; Fundamental and applied biological sciences. Psychology; host plants; IAA; indole acetic acid; Klebsiella; Maize; Microbiology; nucleotide sequences; PGPR; Phosphate solubilization; phosphates; Physics, chemistry, biochemistry and biology of agricultural and forest soils; plant growth; plant growth-promoting rhizobacteria; rhizosphere; rhizosphere bacteria; ribosomal DNA; roots; screening; Siderophore; siderophores; Soil science; Zea mays; South America; Brazil; America; IAA; Maize; Phosphate solubilization; Bacterial diversity; Siderophore; PGPR; Phosphates; Monocotyledones; Auxin; Growth; Biodiversity; Solubilization; Temperate zone; Cereal crop; Gramineae; Indoleacetic acid; Angiospermae; Plant growth substance; Bacteria; Plant growth promoting rhizobacteria; Soil science; Zea mays; Ecology; Screening; Spermatophyta
• ISSN: 0929-1393; 1873-0272
• DOI: 10.1016/j.apsoil.2012.09.001

► We obtained 292 bacterial isolates from five maize crop areas. ► Bacterial strains were characterized about PGPR traits. ► There is a diverse population of PGPR in the rhizosphere and roots of maize. ► The dominant bacterial genera were Klebsiella and Burkholderia. ► Some strains were effective as PGPR in two maize cultivars. Plant growth-promoting rhizobacteria (PGPR) are considered to have a beneficial effect on host plants and may facilitate plant growth by different mechanisms. In this work, the influence of different soil types on the bacterial diversity and the stimulatory effects of selected PGPR on two cultivars of maize were investigated. A set of 292 strains was isolated from the roots and rhizosphere soil of maize cultivated in five different areas of the Rio Grande do Sul State in Brazil. 16S rDNA-PCR-RFLP and 16S rDNA partial sequencing were used for identification, and the Shannon–Weaver index was used to evaluate bacterial diversity. We evaluated the ability of each isolate to produce indole acetic acid (IAA), siderophores and solubilize phosphates. On the basis of multiple PGP traits, six isolates were selected to test their potential as plant growth-promoting rhizobacteria on maize plants. In both the roots and the rhizospheric soil of maize, the dominant bacterial genera identified were Klebsiella and Burkholderia. IAA producers were distributed widely among isolates, regardless of the sampling site. Approximately 42% of the isolates exhibited at least two attributes, and 24% showed all three PGP traits. Three strains, identified as Achromobacter, Burkholderia, and Arthrobacter, were effective as PGPR in both of the cultivars evaluated.