Isolation, molecular identification, and in vitro control of endogenous bacteria of Campomanesia rufa (O. Berg) Nied.

Abstract Campomanesia rufa (O. Berg) Nied. (Myrtaceae) is a species native to the Cerrado. In vitro conservation is an option for endangered species such as C. rufa. The lack of effective protocols for the disinfection of endophytic microorganisms naturally present in the plant hinders the success of micropropagation. Within this context, the objective of this study was the molecular identification and in vitro control of contamination using antibiotics. Purified PCR products of the bacterial isolates were sequenced by the Sanger method. The sequences obtained were aligned with homologous sequences using the Basic Local Alignment Search Tool. The sequences obtained in this study and the homologous sequences listed in GenBank were aligned using MEGA7 software to draw phylogenetic trees. The survival, shoot height, and efficiency of antibiotics (streptomycin, ampicillin, chloramphenicol) at different concentrations (0, 32, 64, 128, 256 mg L− 1) in the culture medium were evaluated at 25 days. The occurrence of Bacillus sp. and of different strains was observed in the plant. When testing the control of Bacillus sp. with antibiotics, ampicillin at 32 mg L− 1 caused a significant reduction in bacterial contamination without affecting the survival of explants. On the other hand, streptomycin caused the greatest reduction in contamination at 256 mg L− 1 but was lethal to more than 90% of explants at this concentration. This study is the first report on the occurrence of endogenous bacteria and their control in the context of the conservation of native species.