Inoculation of endophlytic diazotrophic bacteria in micropropagated seedlings of sugarcane (Saccharum officinarum sp.)

The inoculation of diazotrophic endophytic bacteria in micropropagated sugarcane plants has been utilized in studies on the association between plants and diazotrophic bacteria, allowing us to evaluate the potential of BNF and growth promotion. The objective of this study was to evaluate the effects of inoculation (alone and in a mixture) of different strains of endophytic bacteria from the sugarcane variety RB867515, collected in northeast Brazil, on sugarcane growth at the initial growth stage (45 and 120 days after inoculation—DAI). For this purpose, two experiments were carried out in a greenhouse at the Agronomic Institute of Pernambuco (IPA), located in the city of Goiania, PE, Brazil, in a completely randomized design. The first experiment, with micropropagated seedlings grown in tubes at 45 DAI, was composed of uninoculated plants, plants inoculated in vitro with three individual endophytic bacterial isolates, and plants inoculated in vitro with a mixture of all three bacterial isolates. The second experiment, at 150 DAI, consisted of inoculated plants transplanted to pots with nonsterile soil without nitrogen fertilization and uninoculated plants with nitrogen fertilization equivalent to 80 kg of N ha−1. The variables analyzed were the shoot and root dry weight, tillering and N content accumulated in the plant. At 45 DAI, there was no significant difference between the inoculated plants and the uninoculated control. The inoculation of nitrogen-fixing bacteria native to the northeast region in micropropagated seedlings of sugarcane variety RB867515 grown in pots promoted plant development and presented similar performance to the nitrogen treatment at 150 DAI.