Ocorrência de populações naturais de Ampelozizyphus amazonicus ducke. e Piper peltatum l. ao longo dos rios Solimões e Amazonas e estratégias de conservação ex situ de germoplasma por técnicas in vitro, temperaturas sub zero e criogênicas

Abstract

Piper peltatum (Piperaceae) and Ampelozizyphus amazonicus (Rhamnaceae) are species that have important medicinal features proven, for example, the action against malaria. Both are used as medicinal by the Amazonian peoples, and are obtained exclusively by the practice of extraction. These species are not scientifically well-known, and, due to their potential, studies about methodologies for the conservation of genetic resources and the domestication of these species are necessary. The objectives of this study were to locate and characterize, based on field observation and environmental data base, the natural populations of these species along the Amazon River, and developing strategies for conservation of Ampelozizyphus amazonicus and Piper peltatum germplasm by minimum growth techniques and sub-zero and cryogenic temperatures. For in vitro conservation minimum growth techniques were used. The maintenance of P. peltatum microshoots was evaluated under different temperatures (10 °C, 20 °C and 25 °C) and different salts concentrations in MS medium. Microshoots of P. peltatum and Ampelozizyphus amazonicus were subjected to different concentrations of sucrose, mannitol and sorbitol (1%, 2% and 3%). Microshots of P. peltatum were also subjected to culture media with different concentrations of sucrose, mannitol and sorbitol (1%, 2% and 3%) with or without salicylic acid (SA). Seeds conservation of Piper peltatum were evaluated under sub-zero (-20 °C) and cryogenic (-196 °C) temperatures. For seeds preservation under sub-zero temperatures, the seeds were desiccated for 0h, 24h and 48h and maintained for 0, 90 and 180 days in temperature of -20 °C. For cryopreservation, seeds were immersed in liquid Nitrogen for 24h, and stored with or without other cryoprotectors. Field observation and the data base demonstrate that most of sampling areas visited are under anthropic deforestation. The In vitro maintenance of P. peltatum microshoots was more efficient in the temperature of 20 °C. The use of mannitol for conservation in vitro resulted in high mortality rates of the microshoots of both species. In vitro conservation of P. peltatum in function of sucrose, mannitol e sorbitol and different concentrations of SA, the best results are obtained in the absence of AS. Germination rates were satisfactory when the seeds of Piper peltatum were dried for up to 48 hours and stored for up to 180 days at -20 ° C. The seeds were also tolerant to cryopreservation, regardless of the use of cryoprotectants. It is possible the conservation of the species in vitro for up to 180 days by reducing the growth temperature. The addition of mannitol and sorbitol, for the concentrations tested, are inadequate for in vitro conservation of A. amazonicus microshoots. Sorbitol may be used in P. peltatum conservation in concentrations between 1% and 2% in MS medium. Piper peltatum seeds are tolerant to desiccation and exposure to subzero and cryogenic temperatures, suggesting that Piper peltatum seeds are orthodox.