A Simple and Efficient Protocol for the Cryopreservation of Zygotic Embryos of Macaw Palm [Acrocomia aculeata (Jacq.) Lodd. Ex Mart.], A Tropical Species with A Capacity for Biofuel Production.

BACKGROUND: The development of cryopreservation protocols for zygotic embryos has the advantage of direct embryo regeneration into plantlets, an important factor when one´s purpose is to preserve genetic plant resources. OBJECTIVE: Current study developed an efficient and simplified cryopreservation protocol for zygotic embryos of the macaw palm, a type of palm tree with great capacity for biodiesel production. MATERIALS AND METHODS: Embryos were obtained from seeds and rehydrated for 15 h in a 3% sucrose medium. Zygotic embryos were subsequently desiccated in a laminar flow cabinet for 0, 2, 4, 6 and 8 h. After each period, some embryos were cultured on a germination medium and others were placed in sterile cryotubes and immersed directly in liquid nitrogen for up to 360 d. Cryotubes were rewarmed by immersion at 40 degree C during 90 s (quick thawing). RESULTS: Germinability reduction occurred in proportion to desiccation time, with averages of 97 and 75% for 0 h and 8 h, respectively. In the case of cryopreserved zygotic embryos, the highest germination (81%) was obtained after 6-h desiccation, when the embryos had approximately 10% water content (FW basis). CONCLUSION: The zygotic embryos cryopreservation protocol covered in this study represents another option for preserving Acrocomia aculeata genetic resources.