The goal of the present study was to evaluate the germination, initial growth, and in vitro co-cultivation of Comanthera curralensis Moldenke, a "sempre viva" native of the Chapada Diamantina state of Bahia. Full strength (MS) and half-strength MS (MS1/2) growth media supplemented with two different sucrose concentrations (15 and 30g L-1) were tested for germination and initial plant growth. Three different plant densities were tested by in vitro culture (8, 10 and 12 plants per container). MS1/2 medium with 15g L-1 sucrose resulted in a higher percentage of germination and plant growth for the in vitro establishment of C. curralensis. The use of 12 plants per container is indicated for cost reduction in C. curralensis in vitro production.

Sincoraea mucugensis (Wand. & A.A. Conc.) LOUZADA & WAND, an endangered bromeliad, is confined to the central region of the Chapada Diamantina, in the municipality of Mucugê, Brazil. From various researches, it is evident that for the propagation of this species, the in vitro technique is a feasible option. However, due to the low multiplication rates reported in various papers, this study aimed to establish a micropropagation protocol of direct organogenesis for S. mucugensis. First, the inoculation of the stem explants was done in MS ½ culture medium which contained different levels of BAP (0.00; 6.66; 8.88; 11.10; 13.20 µM) and NAA (0.00; 2.60; 5.20 µM). These shoots were then subjected to a couple of distinct rooting periods (of 30-and 60-day duration) using activated charcoal; finally, these microplants were transferred to a greenhouse for acclimatization, and covered with transparent plastic cups, as a water loss prevention test method. All the data were submitted to the analysis of variance (ANOVA), and the means were subjected to regression analysis or compared using the Tukey test. The findings revealed that the S. mucugensis stem explants raised in the NAA-rich medium (6.42 to 7.43 shoots/explants) showed high multiplication rates; the shoot rooting was done for 30 days using activated charcoal with the medium. Acclimatization, which was performed by directly exposing the microplants to the ex vitro environment, showed 95% survival rate. RESUMO: Sincoraea mucugensis (Wand. & A.A. Conc.) LOUZADA & WAND é uma bromélia vulnerável de ocorrência restrita ao município de Mucugê, Chapada Diamantina. Estudos indicam que a cultura de tecidos é uma alternativa viável para a propagação in vitro destaespécie. Contudo, em função das baixas taxas de multiplicação obtidas em estudos anteriores, objetivou-se estabelecer um protocolo de micropropagação via organogênese direta para S. mucugensis. Explantes caulinares foram inoculados em meio de cultura MS ½ contendo diferentes concentrações de BAP (0,00; 6,66; 8,88; 11,10; 13,20 µM) e ANA (0,00; 2,60; 5,20 µM). Os brotos obtidos foram submetidos a diferentes períodos de enraizamento (30 e 60 dias) com carvão ativado; posteriormente as microplantas foram aclimatizadas em casa de vegetação, testando-se o efeito da cobertura com copos plásticos transparentes como estratégias contra perda de água. Os dados foram submetidos à análise de variância (ANOVA) e as médias analisadas por regressão ou comparadas pelo Teste de Tukey. Os resultados demonstram que altas taxas de multiplicação de S. mucugensis são geradas a partir de explantes caulinares cultivados em meio contendo ANA (6,42 a 7,43 brotos/explantes); o enraizamento dos brotos é realizado por 30 dias em meio com carvão ativado e a aclimatização é feita com exposição direta das microplantas ao ambiente ex vitro com 95% de sobrevivência. Palavras-chave: propagação in vitro, aclimatização, Sincoraea mucugensis, ANA.

Bromeliads are the target of predatory extractivism and consequently many species are included in the red list of threatened species, such as those belonging to the genus Neoregelia. Although Neoregelia mucugensis has not been evaluated for the degree of threat, its exploitation is exclusively extractive and its occurrence in Chapada Diamantina-BA is subject to the action of fires that affect the region annually. In this context, applying techniques aimed at protecting this genetic resource is fundamental for both the maintenance of its natural populations and the ex situ conservation of this genetic material. Plant tissue culture techniques have been successfully applied for the conservation of several bromeliad species. One of the methods used is slow growth, which consists in reducing plant metabolism and consequently decelerating its growth, which allows the maintenance of in vitro plant collections without the need for subculture. In this context, the objective of this study was to test the reduction of salts in the culture medium and the addition of osmoregulators on the induction of slow growth of N. mucugensis. Plants were subjected to treatments composed of different concentrations of MS medium and mannitol for a period of 12 months, when then analyses were conducted to evaluate growth, chlorophyll content and regeneration capacity of shoots in vitro. It was found that the treatment containing MS ½ and 7.8 g.L-1 of mannitol is indicated for in vitro conservation of N. mucugensis with maintenance of the regenerative capacity of its tissues.

No abstract

The “sempre-viva” species Comanthera mucugensis is endemic to the municipality of Mucugê, Bahia, Brazil, where it was widely exploited through extractivism to be commercialized as an ornamental, causing a drastic reduction of its population, so that it is now classified as endangered. Although its main area of occurrence is now protected for being within Chapada Diamantina National Park, the continued risks of inclement conditions and anthropic actions make it necessary to develop alternative methods for ex situ conservation of the species, such as in vitro conservation. Therefore, the objective of this study was to test the effect of different concentrations of salts and sucrose on the in vitro conservation of Comanthera mucugensis. Two salts concentrations of the medium MS (½ and ¼) and two sucrose levels (7.5 and 15.0 g L-1) were tested, and the experimental design was completely randomized with four treatments. After 365 days, the survival, growth and regeneration of the conserved plants were analyzed, achieving up to 100% survival, reduced shoot growth and maintenance of regenerative capacity. Reduction of the concentration of salts and sucrose in the culture medium is indicated to conserve the plants in vitro for a period of one year.