Scientific Study from the year 2017 in the subject Biology - Botany, grade: 1.5, Mar Augusthinose College, language: English, abstract: In this study, the callus initiation and rhizogenesis of Justicia gendarussa from nodal and leaf explants were established in Murashige and Skoog medium supplemented with different hormonal concentrations and also optimization of callus initiation at hormonal concentrations. As a result the callus was initiated on MS medium supplemented with different hormones. The higher concentration of NAA and BA induced callus from nodal and leaf explants. The higher concentrations of 2, 4 - D and kinetin induced callus on nodal explants. Lower concentration of 2, 4 - D and kinetin induce callus on leaf explants. The combination of NAA and kinetin induce rhizogenesis from nodal explants. The antimicrobial activity of callus was evaluated by well diffusion method. Escherichia coli, Pseudomonas aeruginosa, Bacillus subtilus, Staphylococcus aureus, Klebsiella pneumonia were used as test organisms. The results showed that Justicia gendarussa have antimicrobial activity on Escherichia coli, Klebsiella pneumonia, and Staphylococcus aureus. Keywords: Justicia gendarussa, callus initiation, direct organogenesis, antimicrobial assay.