<b>Cryopreservation of the mangaba tree (<em>Hancornia speciosa</em> Gomes): a protocol for long-term storage

Abstract

ABSTRACT. The aim of this study was to evaluate the efficiency of vitrification and droplet vitrification for the cryopreservation of Hancornia speciosa shoot tips. The shoot tips were subjected to four different periods of exposure (15, 30, 45 and 60 min.) to plant vitrification solution 2 (PVS2) before plunging into liquid nitrogen. We evaluated the regrowth of H. speciosa shoot tips that were cryopreserved by the classical vitrification technique and by the droplet vitrification technique. Shoot tips were submitted to different periods of pre-culture (absence, 24 or 48h) in a medium containing 0.3 M sucrose prior to cryopreservation. With a PVS2 exposure period of 60 min., significant differences were observed between the two techniques used in this study with respect to regrowth rates; however, both cryopreservation methods allowed for a shoot tip regrowth rate of over 70%. Use of a preculture step increased the regrowth rate of cryopreserved shoot tips. Shoot tip cryopreservation techniques employing vitrification and droplet vitrification proved to be viable for the long-term storage of mangaba tree samples.Keywords: native species, in vitro conservation, recalcitrant seeds, plant genetic diversity conservation, vitrification, droplet vitrification.Criopreservação de mangabeira (Hancornia speciosa Gomes): um protocolo para armazenamento a longo prazo RESUMO. O objetivo deste trabalho foi avaliar a eficiência da droplet vitrification e vitrificação na criopreservação de ápices caulinares de mangabeira. Foi avaliada a retomada de crescimento de ápices de mangabeira criopreservados conforme a técnica de droplet vitrification utilizando diferentes tempos de tratamento com a solução de vitrificação (15, 30, 45 e 60 min.) e submetidos a diferentes períodos de pré-cultivo (ausência, 24 ou 48h) em meio com 0,3 M de sacarose antes da criopreservação. Além desta técnica, foi avaliado o efeito da técnica clássica de vitrificação utilizando quatro tempos de exposição à solução de vitrificação (15, 30, 45 e 60 min.). Foram observadas diferenças significativas no tempo de exposição para a técnica de vitrificação e droplet vitrification. Para ambas as técnicas o tempo de imersão de 60 minutos promoveu uma retomada de crescimento superior a 70% nos ápices criopreservados. O pré-cultivo promoveu o aumento na sobrevivência dos explantes criopreservados. As técnicas de criopreservação de ápices caulinares por droplet vitrification e vitrificação mostraram-se viáveis para a conservação em tempo prolongado de mangabeira.Palavras-chave: espécie nativa, conservação in vitro, sementes recalcitrantes, conservação da diversidade vegetal, vitrificação, droplet vitrification.

Genetic diversity in natural populations of Hancornia speciosa Gomes: Implications for conservation of genetic resources

“…It presents, predominantly, zoochory dispersion, with the hoary fox (Lycalopex vetulus) being one of its dispersers (Dalponte;Lima, 1999). The seeds are recalcitrant, and the propagation by asexual pathways is uncommon (Santos et al, 2015), which hinders the production of seedlings and natural regeneration.…”

Effect of Desiccation Time on Seed Moisture and Regeneration of Mangaba (Hancornia speciosa) Embryos

“…Some authors have already described research works with the cryopreservation technique applied to lateral buds and apical meristems of mangaba tree. Efficient results have been reported with the droplet vitrification and vitrification techniques with more than 70% regeneration of shoot tips after cryopreservation [12]. Using the droplet vitrification technique, the same authors obtained 90% shoot tip growth resumption.…”

Biometric characteristics of fruits, seeds and plants of Hancornia speciosa Gomes. (Apocynaceae)

“…In addition, studies have reported that the leaf extract has antihypertensive and vessel dilator effects (Pereira et al, 2012), whereas the latex has anti-inflammatory properties (Marinho et al, 2011). Due to the high economic and medicinal potential this species has been widely used in the reforestation programs of the Cerrado region (Santos et al, 2015;Almeida et al, 2016). Biometric characterization consists in evaluating morphological traits of different parts of the plant, such as fruits and seeds, or of the plant as a whole (Silva et al, 2017a).…”

“…The use of seeds is the most widely used method for the propagation of mangaba plants. However, as this species produces recalcitrant seeds, the sexual propagation is hampered (Santos et al, 2015). Therefore, the success of seed utilization depends on a rapid and uniform emergence of seedlings in the nursery or field (Barros et al, 2010;Vieira et al, 2015).…”