Abstract

GONZALEZ MANCILLA, Apolinar et al. CHARACTERIZATION AND SELECTION OF PLANT GROWTH PROMOTING RHIZOBACTERIA IN POBLANO PEPPER SEEDLINGS ( Capsicum annuum L.). Rev. Int. Contam. Ambient [online]. 2017, vol.33, n.3, pp.463-474. ISSN 0188-4999.  https://doi.org/10.20937/rica.2017.33.03.09.

The use of high doses of fertilizers is common in chilli pepper grown, which if are not fully utilized by plants, exerts negative effects on the environment. The use of beneficial microorganisms can be an alternative to reduce high fertilization rates. In the present work, rhizobacteria strains from the Sierra Nevada region, Puebla, Mexico, were isolated in order to assess their potential to promote plant growth of poblano chilli seedlings. The strains were characterized by their capacity to solubilize phosphates, fix nitrogen, and produce auxins. The best 10 strains were evaluated for their ability to promote plant growth, and were finally identified at the molecular level. A total of 215 strains were isolated, from which 74 strains were phosphate solubilizers, releasing between 10 and 881 µg/mL of soluble phosphate, 70 strains had the ability to grow in a nitrogen-free medium, and 71 strains produced between 20 and 27 µg/mL of indoles. The inoculated strains caused significant effect on plant growth (Tukey, p <0.05), the best being Serratia plymuthica CPPC55 and Rhizobium nepotum CPAC35, which increased the shoot weight by more than 20 %. Both strains can be used to increase the quality of poblano chilli seedlings, which could ensure better establishment and plant health in the field. The lands where poblano chilli crops are grown are a source of microorganisms that can be used as plant growth promoters in species of agricultural importance.

Keywords : phosphate solubilization; auxin production; soil microorganisms; seedling growth; Serratia.