Micropropagation and in vitro conservation of Alcantarea nahoumii (Bromeliaceae), an endemic and endangered species of the Brazilian Atlantic Forest

Abstract

Alcantarea nahoumii (Leme) J. R. Grant is a species native to the Atlantic Forest that stands out for ornamental purposes. The objective of this work was to evaluate the in vitro germination of A. nahoumii seeds and establish a micropropagation protocol for production of seedlings so as to minimize the effects of predatory extractivism and develop an in vitro conservation system. Mature seeds were disinfested, established in three culture media (MS, MS½ and MS⅓) and incubated at four temperatures (20, 25, 30 and 35ºC) in a germination chamber. In the micropropagation experiment, stem segments were introduced in MS medium supplemented with 0.5 μM of 1-naphthaleneacetic acid (NAA) and 0.0, 2.2, 4.4 and 6.6 μM of 6-benzylaminopurine (BAP). For the in vitro conservation, plantlets were established in MS or MS½ medium supplemented with 15 g L-1 or 30 g L-1 of sucrose. The plants were acclimated with commercial substrate. The highest seed germination percentages were promoted by temperature conditions of 20 and 25ºC, with MS culture medium. The highest multiplication rate of shoots was obtained from the treatment without addition of the growth regulator or when combined with 2.2 μM of BAP + 0.5 μM of NAA. The acclimation of the plants occurred with high survival rate. The species can be conserved in vitro under slow growth condition for 24 months when incubated in MS medium supplemented with 30 g L-1 of sucrose.

Physiological responses of Aechmea setigera Mart. ex Schult. & Schult. f. (Bromeliaceae) in vitro cultured

“…The results observed for the number and length of leaves or roots and the biomass accumulation confirmed that the increased BAP concentration favored A. setigera multiplication rather than the growth of plant organs. Similar results with the use of BAP and ANA were obtained with bromeliad Alcantarea nahoumii (Silva et al, 2020), indicating that the use of this cytokinin in higher concentrations increases the multiplication rate, an important characteristic for the propagation and conservation of the species.…”

“…The in vitro propagation system of bromeliads of Aechmea genera performed from shoots presented viability and can be used as a biotechnology strategy for the conservation of bromeliads, minimizing the extractive activity, as suggested by other authors (Santa- Rosa et al, 2013;Leão et al, 2014, Silva et al, 2020. This system can also be used for clonal propagation of plants with ornamental potential (Guerra and Dal Vesco, 2010;Faria et al, 2018).…”

“…In vitro techniques have been widely used for propagation and as alternative to minimize the extraction of a high number of bromeliads, which are rare or endangered (Guerra and Dal Vesco, 2010). According Silva et al (2020) the germplasm conservation of bromeliads needs to consider the genetic diversity of the species' natural conditions, therefore, the use of in vitro germinated seeds is essential for the maintenance of diversity aiming at in vitro conservation.…”

“…Thus, plant growth regulators can lead to various responses, generate metabolic pathway activation and promote the accumulation or reduction of compounds essential for plant development (Rosa et al, 2018). Guerra and Dal Vesco (2010) (Maláet al, 2013), especially in bromeliads (Silva et al, 2020). Micropropagation studies using BAP of A. setigera are still recent (Leão et al, 2014;Vasconcelos et al, 2015).…”

Assessment of minimum growth conditions for in vitro conservation of Passiflora edulis Sims

“…Among the most popular culture media, the MS medium (Murashige and Skoog, 1962) is widespread in tissue culture research and has been used in in vitro culture of many species in specific concentrations for each of them. In a study developed by Silva et al (2020) with Alcantarea nahoumii (Bromeliaceae), for example, plants grown in MS medium with half the salt concentration had the lowest growth. According to the authors, this fact indicates a metabolism reduction useful for in vitro conservation.…”