Diazotrophic bacteria associated with sisal (Agave sisalana Perrine ex Engelm): potential for plant growth promotion

• Published in: Plant and soil 2014-12, Vol.385 (1-2), p.37-48
• Main Authors: de Jesus Santos, Adailson Feitoza, Martins, Carolina Yamamoto Santos, Santos, Patrícia Oliveira, Corrêa, Élida Barbosa, Barbosa, Heloiza Ramos, Sandoval, Andrea Paola Suarez, Oliveira, Lenaldo Muniz, de Souza, Jorge Teodoro, Soares, Ana Cristina Fermino
• Format: Article
• Language: English
• Subjects: Agave sisalana; Agricultural research; Agricultural soils; Agrochemicals; Agronomy. Soil science and plant productions; Animal, plant and microbial ecology; Arid zones; Bacteria; Biochemistry and biology; Biological and medical sciences; Biomedical and Life Sciences; Burkholderia; Chemical, physicochemical, biochemical and biological properties; cucumbers; Cucumis sativus; Ecology; endophytes; epiphytes; fertilizers; Fundamental and applied biological sciences. Psychology; General agronomy. Plant production; Growth (Plants); growth promotion; Health aspects; Leaves; Leifsonia; Life Sciences; Microbiological research; Microbiology; Nitrogen; Nitrogen fixation; Nitrogen fixing bacteria; Nitrogen-fixing microorganisms; nucleotide sequences; Paenibacillus; Physics, chemistry, biochemistry and biology of agricultural and forest soils; Plant growth; Plant growth promoters; Plant Physiology; Plant roots; Plant Sciences; Plant tissues; Plant-soil relationships; Plants; polymerase chain reaction; Regular Article; Rhizosphere; rhizosphere bacteria; ribosomal RNA; roots; Semiarid lands; semiarid zones; sequence analysis; sisal; Sisal hemp; soil; Soil bacteria; Soil microorganisms; Soil science; Soil Science & Conservation; Soil-plant relationships. Soil fertility; Soil-plant relationships. Soil fertility. Fertilization. Amendments
• ISSN: 0032-079X; 1573-5036
• DOI: 10.1007/s11104-014-2202-x

AIMS: In the semi-arid region of Bahia State, Brazil, sisal (Agave sisalana Perrine ex Engelm) has been cultivated for fibre production for several decades without the use of chemical fertilizers. The contribution of biological nitrogen fixation (BNF) to this crop and the occurrence of diazotrophic rhizosphere, epiphytic or endophytic bacteria have not been investigated. The aims of this work were to study the occurrence and diversity of diazotrophic bacteria in rhizosphere soil, root and leaf tissues of sisal plants from this region, as well as to test their potential for plant growth promotion. METHODS: Burk’s nitrogen free semi-solid medium was used for isolation and the MPN method was used for quantification of diazotrophic bacteria. BOX-A1R PCR and 16S rRNA sequence analyses were performed to study the diversity of bacterial isolates harboring the nifH-gene. Six isolates were selected for growth promotion of cucumber plants. RESULTS: A high diversity of BNF bacterial isolates was observed in sisal plants and rhizosphere soil. Bacterial populations were higher in roots, followed by soil and sisal leaves. Burkholderia, Leifsonia and Paenibacillus were the predominant genera. All isolates tested were able to promote cucumber growth. CONCLUSIONS: This study showed that sisal-associated diazotrophic bacteria are diverse and may be further exploited to promote plant growth.