INOCULATED GROWTH PROMOTING RHIZOBACTERIA IN SERRANO CHILI PEPPER (Capsicum annuum L.) SEEDLINGS UNDER ABIOTIC STRESS CONDITIONS.

Mexico is the world's second largest chili pepper producer. Its production requires high amounts of chemical fertilizers, generating environmental problems such as water scarcity and soil salinity. There are alternatives to reduce this problem, one of them is the use of plant growth promoting rhizobacteria. The hypothesis of this work was that by inoculating chili pepper (Capsicum annuum L.) seedlings with growth-promoting rhizobacteria, the effects caused by salt and water stress are reduced and their growth is promoted. The objective was to evaluate five bacterial strains with growth-promoting capacity in the production of chili pepper seedlings grown under salt and water stress. A completely randomized experimental design with factorial arrangement (AxB) was used, where factor A (bacterial strain) had five levels (strains of different species), and factor B (substrate moisture content) four levels (100, 75, 50, and 25 %), having 24 treatments with five replicates each, generating 120 experimental units. Moisture was maintained with the application of a NaCl solution in water in all experimental units. Plant height, root length, fresh weight, dry matter, seedling sodium concentration, and the presence of rhizobacteria in the root were evaluated. The rhizobacterium Acinetobacter johnsonii showed significant differences with respect to the control without inoculation for the variables plant height with 12.4 cm, root length with 10.6 cm, fresh weight with 1.266 g, and dry matter with 0.394 g; for the concentration of Na+ in the plant, the rhizobacterium ixta gaviniae obtained a concentration of 3.60 g of Na+ per kg of seedling with respect to the control without inoculation. Therefore, these rhizobacteria can be used as an alternative method to control water and salt stress in chili pepper seedlings and improve their initial development. [ABSTRACT FROM AUTHOR]