Isolation and characterization of potential plant growth-promoting bacteria from sugarcane

MICHAVILA M.G.; RACEDO, J.; CLAPS, P.; CIACCIO M.; ALIBRANDI P.; CINÀ P.; GALLO G.; WELIN G.V.B.; CASTAGNARO, A. P.

Congreso; XXX International Society of Sugarcane Technologists Congress; 2019

The inappropriate use of agrochemicals to improve crop production can be hazardous for both the environment and human/animal health. It is therefore of great interest to develop effective and more environmental-friendly crop management alternatives, like the use of Plant Growth-Promoting Bacteria (PGPB). PGPB can enhance plant growth and protect plants from biotic and abiotic stresses. In general, biological control mechanisms and plant growth promotion by PGPB are based on microbial metabolites that can adversely affect the pathogen, induce systemic resistance in the plant and/or improving plant growth. The aim of this work was to isolate PGPB from sugarcane roots, stalks, and rhizosphere that potentially could promote plant growth and generate stress protection. Biochemical markers associated with growth promotion and microbial antagonism of the bacterial isolates, i.e. siderophore production, synthesis of indole acetic acid (IAA), phosphate solubilization and antibiotic production were studied. In addition, isolates were taxonomically characterized by sequence comparison of the16S rRNA coding DNA. A total of thirty-two strains were isolated that exhibited a variable capacity of producing IAA and siderophores, phosphate solubilization, nitrogen-fixation, antibiotic production and tolerance to osmotic and salt stress. These isolates belonged to several bacterial genera and revealed a great bacterial diversity. Several isolates showed important plant growth promoting abilities, indicating their usefulness in development of bioinoculants intended for sugarcane management.