Micropropagation of Piper crassinervium: an improved protocol for faster growth and augmented production of phenolic compounds

摘要

The medicinal plant Piper crassinervium is a source of bioactive compounds with potential use in agrochemical and pharmaceutical industries. However, its propagation is slow and influenced by the composition of the culture medium and growth conditions. In the genus Piper, tissue oxidation limits the biomass and recovery of bioactive compounds such as phenols. We evaluated the effect of medium formulations, sucrose, growth regulators, medium consistency, explant type, gas exchange and irradiance levels on growth and phenols and total flavonoids content in P. crassinervium in vitro plants. Murashige and Skoog (MS) and DKW/Juglans(DKW/J) media induced the highest production of chlorophyll and phenolic compounds; however,the regenerationrate of the explantsin the DKW/J medium wasthe lowest (75%) in comparison with the other media(90%). The maximum biomass production was achieved when half-strength MS (1/2MS) liquid medium was used; while the optimum sucrose level depended on the medium salt concentration used. Notably, the irradiance altered the accumulation of biomass and phenolic compounds. The presence of one remaining leaf in the nodal segments, used as explants, produced taller plants in 1/2MS liquid medium, combined or not with 2-iP. The optimal growth conditions for biomass and phenolic compound production in P. crassinervium in vitro plants established were: nodal explant with a preexisting leaf cultured on 1/2MS stationary liquid medium, 15gL(-1) sucrose, using lids with one PTFE 0.45-mu m-poresize membrane and an irradiance of 100 mu molm(-2)s(-1). Key messageMedium formulation, sucrose concentration, irradiance levels, gas exchange and explants with preexisting leaf improved the in vitro propagation and phenolic compounds production in Piper crassinervium.