Caracterização de diásporos e conservação ex situ de populações de Butia capitata [Mart. (Becc.) Arecaceae]

Popularmente conhecida como butiá ou cabeçudo o coquinho-azedo (Butia capitata) é uma espécie de palmeira endêmica do Bioma Cerrado, na região próxima a divisa dos estados de Goiás, Minas Gerais e Bahia. Esta espécie destaca-se pela utilização como alimento e pelo comércio de produtos derivados de frutos, sementes e folhas. Esse estudo teve por objetivo caracterizar diásporos de três populações de coquinho-azedo (Arinos, Mirabela e Serranópolis), além de desenvolver estratégias de conservação ex situ da espécie, por meio do armazenamento de sementes e embriões zigóticos a médio-longo prazo em várias temperaturas, incluindo subzero. Inicialmente, frutos, sementes e embriões foram caracterizados quanto suas características morfológicas. Para a conservação, sementes das três populações foram armazenadas nas temperaturas de 25 °C, 6 °C, -20 °C e -196 °C por até 360 dias. Em outro experimento, embriões zigóticos foram criopreservados com diferentes teores de umidade. Como resultado, observou-se que a população de Arinos apresentou resultados mais expressivos para a maioria dos caracteres avaliados, como por exemplo comprimento e largura dos frutos e sementes. A conservação de sementes das três populações mostrou-se viável em temperaturas ultrabaixas (-20 e 196 °C), quando armazenadas em períodos de até 360 dias e com umidade próxima a 5%. A criopreservação de embriões zigóticos mostrou-se eficiente com na conservação da espécie atingindo taxas de germinação entre 70 e 86%, quando a umidade dos embriões mergulhados em nitrogênio líquido estavam entre 10 e 14%. Na fase de aclimatização as plantas que chegaram até a etapa da casa de vegetação apresentaram 90% de sobrevivência. _________________________________________________________________________________________________ ABSTRACTPopularly known as butiá or jelly palm, the “coquinho-azedo” (small coconut-sour), Butia capitata is an endemic palm species from the Cerrado biome, especially from the region near the border of the states of Goiás, Minas Gerais and Bahia. This specie stands out by the use as food and by the trade of products derived from fruits, seeds and leaves. This study aimed to characterize diaspores from three populations of “coquinho-azedo” (Arinos, Mirabela and Serranópolis) and to develop strategies for the ex situ conservation of the specie. These strategies included the mid and long-term storage of seed and zygotic embryos under many temperatures, including subzero. Initially, fruits, seeds and embryos were morphologically characterized. For the preservation of the three populations, seeds were stored at temperatures of 25 ° C, 6 ° C, -20 ° C and -196 ° C for up to 360 days. In another experiment, zygotic embryos were cryopreserved with different moisture contents. As a result, it was observed that the population of Arinos presented better results for most characters, such as length and width of fruits and seeds. The seed conservation of the three populations showed to be feasible in ultralow temperatures (-20 to 196 ° C) when stored for periods up to 360 days and moisture content around 5%. Cryopreservation of zygotic embryos was efficient allowing the conservation of the specie, whose germination rates reached from 70 to 86% when the humidity of embryos conserved in liquid nitrogen were from 10 to 14%, respectively. In the acclimatization phase, the plants that have reached the appropriate stage to the greenhouse had 90% survival

Designing Ex Situ Conservation Strategies for <i>Butia capitata</i> [Mart. (Becc.) Arecaceae], a Threatened Palm Tree from Brazilian Savannah Biome, through Zygotic Embryo Cryopreservation

Jelly palm (Butia capitata) is a species of palm tree endemic to the Brazilian Savannah (Cerrado) Biome, which stands out for its use as food, which has resulted in a predatory exploitation of its natural populations. This study aimed to characterize fruits and diaspores of natural populations of jelly palm (‘Arinos’, ‘Mirabela’ and ‘Serranópolis’), in addition to developing ex situ conservation strategies of the species, through the storage of zygotic embryos at ultra-low temperatures of liquid nitrogen (LN). Initially, fruits, seeds and embryos were evaluated for their morphological characteristics. For conservation, hydrated zygotic embryos were desiccated for up to 12 h in a laminar-flow chamber and immersed directly in LN with different moisture contents. As a result, we observed morphological differences among the studied populations. The population ‘Arinos’ showed more expressive results for most of the evaluated characteristics, such as length, width of fruits and seeds. The cryopreservation of zygotic embryos proved to be efficient for the conservation of the species reaching germination rates between 70 and 86%, when the moisture content of the embryos immersed in LN were between 10 and 14%. The plants that reached the stage of the greenhouse had a rate of more than 80% survival. The variability in the characteristics of fruits and diaspores of the analyzed populations allow for establishing divergent groups for the definition of conservation strategies or genetic improvement. The developed cryopreservation protocol can be considered simple and efficient for the conservation of the genetic variability of the species