Indigenous bacterial studies of local lettuce and its application to commercial lettuce cultivation in hydroponic systems

ABSTRACT Plants naturally utilize associated microbes to perform a variety of beneficial functions, including nutrient acquisition. Identifying a consortia of different beneficial microbes that live in harmony with a native ecosystem or living plant is necessary for application in agriculture. The objective of this research was to identify beneficial bacteria for growth promotion in local lettuce and use them in lettuce cultivation in a hydroponic nutrient film technique (NFT) system. Explants of roots (A), stems (B), and leaves (D) from local lettuce were physiologically, genetically, and morphologically identified and utilized in Archivel lettuce production. Indigenous bacteria isolated from local lettuce are capable of IAA production (IPB), nitrogen fixation (NFB) and phosphate solubilization (PSB) and are genetically similar to Marinobacter salsughinis strains 43SY, Delftia acidovorans 11, Brucella rhizosphaerae PB1_7, Stenotrophomonas geniculata 1285, Delftia acidovorans strain 19MWFB29, the uncultured bacterium clone 18447 and the uncultured bacterium clone WBB5. Marinobacter salsughinis strain 43SY, Delftia acidovorans 11, and Brucella rhizosphaerae PB1_7 enhanced the biological freshness, pigmentation, and photosynthate accumulation of Archivel lettuce cultivated in the NFT hydroponic system. These strains have great potential for use in lettuce production and agricultural applications through organic hydroponics.