Physalis peruviana L. (Solanaceae) is an herbaceous fruit-bearing species that has been gaining market acceptance due to its nutritional and medicinal potential. The main limitations to its cultivation are the short reproductive cycle, the susceptibility of the fruits to pests and the lack of information about the crop management. Hence, studies are necessary to develop strategies for its propagation. This study aimed to evaluate the effects of 6-benzylaminopurine (BAP) and explants on the morphogenetic potential of P. peruviana, as well as to establish a protocol for the micropropagation of the species via direct organogenesis. To evaluate the morphogenesis, cotyledonary node, cotyledon, leaf, epicotyl, hypocotyl and root explants were inoculated in Murashige & Skoog culture medium with half the normal concentration of salts and supplemented with cytokinin BAP (0.00 µM, 2.22 µM, 4.44 µM, 6.66 µM or 8.88 µM), plus 30 g L-1 of sucrose and 7 g L-1 of agar. Aiming at a direct production of shoots, the cotyledonary node explant was submitted to 0.00 µM, 2.22 µM, 4.44 µM, 6.66 µM, 8.88 µM, 13.32 µM, 17.76 µM or 22.20 µM of BAP. The obtained shoots were tested regarding their rooting potential in media with and without the addition of activated charcoal and then were transferred for acclimatation. The cotyledonary node and leaf explants were the most efficient sources for the regeneration of shoots via direct and indirect organogenesis, respectively. The most significant results for direct shoot production were obtained with 12.50 µM of BAP. These shoots were successfully rooted in vitro in medium without activated charcoal, and the microplants acclimated in vegetable earth attained 100 % of survival after 90 days of acclimatation.

The genus Melocactus (“cabeça-de-frade”) comprises 32 species in Brazil, of which M. glaucescens and M. paucispinus are threatened with extinction. The present work evaluated the effects of different concentrations of Murashige & Skoog (MS, MS/2 and MS/4) culture medium and sucrose (15 g L-1 and 30 g L-1) on in vitro seed germination and plant growth of M. glaucescens and the efficiency of sterilization with sodium hypochlorite (NaOCl) on in vitro seed germination and plant growth of M. glaucescens when using seeds and M. glaucescens and M. paucispinus when using apical segment of cladode. In M. glaucescens, the final germination at the different MS and sucrose concentrations varied between 53.5 and 68.1% and the best results for in vitro growth were observed with the lowest mineral salt (MS/2 and MS/4) and sucrose (15 g L-1) concentrations, with lengths of the aerial portion of 9.70 and 10.76 mm, respectively. There was no difference in seed germination and plant growth in chemical and autoclave medium. It is concluded that the use of chemical sterilization with NaOCl at low concentrations of salts (MS/2 and MS/4) and sucrose (15 g L-1) are quite advantageous for producing ornamental plants germinated in vitro and/or apical segment of cladode of M. glaucescens andM. paucispinus, representing a reduction of costs for in vitro cultivation of this species.

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.

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.