Unun Triasih, Abdul Latief Abadi, Luqman Qurata A'ini, Dita Agisimanto, Titiek Yuliati
Endophytic bacteria are well-known to have the ability to plant growth promotion (PGP). Application of plant growth-promoting bacteria for lettuce in tropical Indonesia is necessary for ensuring and sustaining food production. The IAA content and its effect on the early growth of lettuce were evaluated under a hydroponic system. Endophytic bacteria were isolated from lettuce, and IAA-producing bacteria were identified and multiplied. Selected isolates were introduced to lettuce seeds in single and consortium and planted in seed nurseries. About three isolates were selected based on IAA level on in vitro test, namely 10A, B1, and 8A at 5.82 ppm, 4.84 ppm, and 5.86 ppm, respectively. The PGP bacteria stimulated lettuce growth differently. Three bacteria consortia were promoted to the highest number (100%) of seed germination and its development 15 days after germination. The root length of seedlings reached 7.4 cm while the control was lower. At the best condition, the average leaf number of individual plants was counted as three leaves, and the stem diameter was 1.5 mm. These PGPBs effectively promoted the early growth of lettuce. © 2026 Author(s).
Department of Plant Protection, Faculty of Agriculture, Brawijaya University, Malang, Indonesia; Research Organization for Agriculture and Food, Research Center for Horticultural and Estate Crops, National Research and Innovation Agency, Indonesia
