RESUMO
Agaves are plants with multiple possibilities of use and are naturally tolerant to low water availability conditions and high temperatures. This makes them species of great interest in the context of the necessary substitution of crops due to climate change. Unfortunately, the overexploitation of wild specimens has endangered many species of the genus that have not been domesticated or cultivated intensively. In vitro mass culture and propagation techniques have emerged as a very efficient option to produce agave plants that can be used without damage to the natural populations. A protocol is presented here for the in vitro micropropagation of agaves in a two-stage process. In the first step, clusters of slightly differentiated shoots are generated from stem segments cultivated on a semisolid medium added with cytokinin. In a second step, these shoot clusters are cultured in temporary immersion bioreactors where they grow and complete their differentiation, and then the shoots are rooted and transferred to soil. This protocol has been successfully applied to several threatened species of the Agave genus.
Assuntos
Agave , Espécies em Perigo de Extinção , Brotos de Planta , Agave/crescimento & desenvolvimento , Brotos de Planta/crescimento & desenvolvimento , Meios de Cultura/química , Reatores Biológicos , Raízes de Plantas/crescimento & desenvolvimento , AclimataçãoRESUMO
Temporary Immersion Bioreactors (TIBs) are used for increasing plant quality and plant multiplication rates. These TIBs are actioned by mean of a pneumatic system. A failure in the pneumatic system could produce severe damages into the TIB. Consequently, the whole biological process would be aborted, increasing the production cost. Therefore, an important task is to detect failures on a temporary immersion bioreactor system. In this paper, we propose to approach this task using a contrast pattern based classifier. We show that our proposal, for detecting pneumatic failures in a TIB, outperforms other approaches reported in the literature. In addition, we introduce a feature representation based on the differences among feature values. Additionally, we collected a new pineapple micropropagation database for detecting four new types of pneumatic failures on TIBs. Finally, we provide an analysis of our experimental results together with experts in both biotechnology and pneumatic devices.
Assuntos
Reatores Biológicos , Falha de Equipamento , Reconhecimento Automatizado de Padrão/métodos , Ananas/crescimento & desenvolvimento , Área Sob a Curva , Bases de Dados como Assunto , Fatores de TempoRESUMO
Deschampsia antarctica (DA), the only species in the Gramineae family endemic to the Antarctic territory, is characterized by a combination of high levels of free endogenous phenylpropanoid compounds under normal in situ and in vitro growth conditions. In this article, we describe the design and use of a specific temporary immersion photobioreactor to produce both increased DA biomass and secondary metabolite accumulation by UV-B elicitation during cultivation. Three min-long immersions in an induction medium applied every 4 hrs at 14ºC +/- 1 and 20/4 hrs light/darkness photoperiod increased DA biomass production over previous in vitro reports. Biomass duplication was obtained at day 10.7 of culturing, and maximum total phenolics and antioxidant activity were observed after 14 day of culturing. The addition of UV-B radiation pulses for 0.5 hrs at 6 hrs intervals increased total phenolics and antioxidant activity more than 3- and 1.5- fold, respectively, compared to controls with no UV-B. Significant accumulation of scopoletin, chlorogenic acid, gallic acid and rutin was found in these plantlets. This is the first bioreactor designed to optimize biomass and phenylpropanoid production in DA.