Inoculation with plant-growth promoting bacteria improves seed germination and initial development of Brachiaria decumbens

Abstract The objective of this research was to evaluate the inoculation and co-inoculation of bacteria with biotechnological potential, isolated from Brachiaria decumbens Stapf. and Brachiaria humidicola (Rendle) Schweickerdt, under germination and seedling growth of B. decumbens cv. Basilisk, as well as, to verify the influence of the co-inoculum in the soil indigenous bacterial community. For this, two assays in a completely randomized design were set up. The experimental period was 21 days. In a germination chamber, 25 treatments were evaluated (24 bacterial inoculants and a control – without inoculation). In greenhouse assay, were used five co-inoculations (bacterial consortium). The bacterial consortium was obtained based on the bacterial strain performance in the germination test. In addition, the control and one treatment with mineral fertilizer (NPK) were tested. In germination test, the seed inoculation promoted increases of 61, 40, 144, 82, 6, 96, 91 and 52% in germination vigor, speed germination index, number of absorbent hairs, number of plumules, primary root length, hypocotyl length, total length, and dry matter of seedlings, respectively, when compared to control. The co-inoculation also increased the growth parameters of B. decumbens plants when compared to the control treatment. In addition, promoted changes in the soil bacterial community structure. Becoming an important strategy to increase the germination rate and germination speed of B. decumbens plants.