Indução de calo em explante de pimenta-do-reino Piper nigrum L.

Abstract

One of the serious problems in the cultivation of Piper nigrum L. is the attack of the fungus Fusarium solani f.sp. piperis, which causes rotting of the roots and stem base. This disease is known as fusarium, which limits the cultivation in up to six years. The in vitro culture techniques are one of the alternatives for the selection of genotypes that may present resistance to this disease. For this, it is necessary to develop somatic embryogenesis techniques, aiming to take advantage of somaclonal variability. In this work we developed experiments to obtain callus, from which the somatic embryos will be obtained. MS (Murashige & Skoog) medium was used, containing 3% sucrose, 0.7% agar, antioxidant and growth regulators (auxin and cytokinin), with the pH of the medium adjusted to 5. 8, where the explants (leaf and hypocotyl segments) of aseptic plants were inoculated, and then incubated in a growth room, where the temperature varied from 270 +/- 10 C, and the relative humidity of the air around 70%, in a 16 h light/day photoperiod. The "explants" from leaf segment were callus in the treatment with 1.0 mg/1 of 2.4-0, and those from hypocotyl segment with the combination of growth regulators 2.4-0 (1.0 mg/1) and BAP (0.2 mg/1). Callus formation started 25 days after incubation. But the conservation of the callus "in vitro", to obtain seedlings, was not possible yet, due to the high oxidation index of black pepper.