Decrease in the incidence of charcoal root rot in common bean (Phaseolus vulgaris L.) by Bacillus amyloliquefaciens B14, a strain with PGPR properties

SABATÉ, DANIELA C.; PÉREZ BRANDAN, CAROLINA; PETROSELLI, GABRIELA; ERRA-BALSELLS, ROSA; AUDISIO, M CARINA

BIOLOGICAL CONTROL

ACADEMIC PRESS INC ELSEVIER SCIENCE

Lugar: Amsterdam; Año: 2017 vol. 113 p. 1 - 8

1049-9644

The objective of this study was to isolatestrains of the genus Bacillus fromdifferent productive soils of the province of Salta, Argentina, which havegrowth promoting properties in common bean (Phaseolusvulgaris L.) and have the ability to inhibit different phytopathogenicfungi, primarily Macrophomina phaseolina.Among the 105 strains of bacilli checked,Bacillus sp. B14 was selected forhaving the greatest in vitroinhibitory effect against Sclerotiumrolfsii, Sclerotinia sclerotiurum,Rhizoctonia solani, Fusarium solani and Macrophomina phaseolina, recording fungal inhibition values thatvaried between 60 and 80%. In addition, B14 produced auxins in a concentrationof 10.10 mg/ml, and qualitatively synthesizes siderophores. Based on 16S rRNAgene sequencing, the strain was characterized as B. amyloliquefaciens. Datafrom greenhouse experiments showed that the black common bean cv. Nag 12 seedsinoculated with B14, had increased germination of 10%, as well as an increasein root length of 2 cm and in shoot length of 6 cm compared with thenon-inoculated control seeds. When the phytosanitary state of the B14 inoculatedseeds was analyzed, no growth of bacteria, or phytopathogenic fungi andcontaminants was observed, while in the non-inoculated seeds, bacteria wasfound in 46% of seeds, in addition to other phytopathogenic fungi. B. amyloliquefaciens B14 reduced theincidence of M. phaseolina by 62% inthe inoculated black bean cv. Nag 12 seeds. Furthermore, using MALDI-MS it was determinedthat the bacteria synthesized different lipopeptides in the presence of M. phaseolina, such as surfactin,iturin, fengycin, kurstatin and polymyxin, leading us to conclude that they arethe main responsible for the antagonistic effect observed and that the natureof lipopeptides synthesized by B14 is influenced by target fungal strain.