Histochemical Screening of Leaves Compared to in situ and in vitro Calluses of Solanum aculeatissimum Jacq

Solanum aculeatissimum Jacq. is a shrub considered to have valuable medicinal potential in folk medicine in China and Nepal. The fruit extract is used for toothache, scabies, headache, dandruff and lice infestation. A limited number of reports address techniques of tissue culture for this plant. Therefore, the objective of the present study was to establish the species in vitro from seeds and subsequently to compare the production of primary and secondary metabolites in the plant’s leaves in situ and in vitro and in calluses obtained from leaf segments. Seedlings were established from seeds in Murashige and Skoog (MS) medium with a 50% salt concentration.The seedlings were kept under a photoperiod of 16 h of photosynthetically active radiation at 45-55 µmol m-2 s-1 provided by fluorescent bulbs. The callus induction experiment followed a completely randomized design consisting of 2 doses of kinetin (KIN), 2.5 and 10 mg L-1, in the absence or presence of light. Segments were inoculated in glass bottles containing 50% MS medium, 30 g L-1 of sucrose, 3.5 g L-1 of agar and 1 mg L-1 of 2,4-D (2,4-dichlorophenoxyacetic acid), with the pH adjusted to 5.7±0.03. We observed that in vitro cultivation of calluses resulted in greater secondary metabolite production and accumulation, regardless of KIN concentration. In calluses, the best alternative for potentiation occurred in cultivation in the absence of light when compared to the tissues of both in situ and in vitro leaves.