Biochemical profile of callus cultures of Pogostemon cablin (Blanco) Benth

Patchouli is an aromatic shrub of commercial interest because its essential oil is rich in patchoulol. This study aimed to evaluate the effect of growth regulators on callus production, analyze the essential oil production in calli and evaluate metabolic differences between callus, in vitro grown-plantlets and greenhouse-grown plants in three different accessions of patchouli. Calli were induced from leaf explants on media supplemented with 2,4-dichlorophenoxyacetic acid (2,4-D) in combination with 6-benzyladenine (BA). The largest size calli from different accessions were obtained in the presence of the two plant growth regulators (PGRs). For accession POG014, presence of 0.022 mg l −1 2,4-D plus 0.022 mg l −1 BA were optimum. For accession POG021, presence of 0.110 mg l −1 2,4-D plus 0.022 mg l −1 of BA induced the largest callus, whereas for accession POG002, 0.022 mg l −1 2,4-D and 0.225 mg l −1 BA, as well as 0.11 mg l −1 2,4-D and 0.022 mg l −1 BA promoted the development of largest callus. Among all accessions, peroxidase activity was highest in organogenic calli of accession POG014, whereas, polyphenol oxidase activity was highest in in vitro-grown plantlets of accession POG021. Biochemical variables differed significantly among the treatments, with the exception of total sugar levels. The highest concentrations of total sugars were observed in the calli and in vitro-grown plantlets of POG014 and POG021. Essential oils were not detected in callus tissues.