Micropropagación y estimativa de producción de mudas de bananos para la Amazonia Occidental

Abstract

El objetivo del trabajo fue de determinar tasas de multiplicación y estimar la producción in vitro de microplantas de las cultivares del banano Preciosa, Maravilha, Pacovan Ken y Japira, durante seis subcultivos y con diferentes concentraciones de BAP. Después de multiplicadas, las microplantas enraizadas fueron aclimatadas, y la sobrevivencia fue determinada después de 30 días. Las tasas de multiplicación fueron de 2,3 y 2,1 brotes por explante de 'Preciosa' y 'Maravilha', respectivamente, y 2,7 brotes por explante de 'Pacovan Ken' y 'Japira', en 4 mg L-1 de BAP. Las pérdidas por contaminación fueron de 22,4%, y la sobrevivencia por lo menos 96%.

<b>Biochemical characterization of systemic bacteria in bananas, sensitivity to antibiotics and plant phytotoxicity during shoot proliferation

“…With these antibiotics added to the medium, the multiplication values of cultures reached approximately 2.0 shoots per explant, similar to the results obtained by Costa, Scherwinski-Pereira, Pereira, and Oliveira (2006) and Oliveira et al (2008) in multiplication experiments of bananas without the addition of any antibacterial agent. Additionally, no symptoms of phytotoxicity were visually observed in the shoots cultivated in medium containing these antibiotics, regardless of the concentrations used.…”

“…Systemic bacteria were isolated from the propagative material of the Maravilha (FHIA 01 AAAB), Preciosa (PV 4285 AAAB) and Thap Maeo (AAB) varieties, previously established in vitro by Oliveira, Costa, and Scherwinski-Pereira (2008). Contaminated material was selected approximately thirty days following establishment, and using a flame-sterilized platinum loop, the contaminants were then transferred individually to Petri dishes containing Nutrient Agar medium (NA) (peptone, 5 g L ; pH 7.0 ± 0.2) for the purpose of purification, based on the morphological characteristics of the bacteria, particularly pigmentation, texture, surface, and border.…”

“…However, the greatest evidence of the source of microbial contamination in the multiplication stage relates to endophytic organisms, as these contaminants are not generally eliminated by disinfectant agents because they are hosted inside the vegetal tissues and are protected from the action of surface disinfectants (Thomas, 2007;Scherwinski-Pereira & Costa, 2010). In the case of bananas, the initial explant for in vitro establishment, and therefore, the raw material used for micropropagation, is usually isolated from apical buds, which are protected from contact with the soil by various layers of tissue (immature leaves), which are eliminated during the sterilization process (Oliveira, Costa, & Scherwinski-Pereira, 2008 explants can present high levels of contamination during the establishment and multiplication phases, constituting the major cause of loss of material during micropropagation of the species (Thomas, Swarna, Patil, Prakash, & Rawal, 2008;Thomas & Soly, 2009). …”

Diluição celular, características do meio de cultura e biorreatores de imersão temporária na diferenciação e regeneração de células em suspensão de bananeira

“…Segundo Silva et al (2006), um dos maiores problemas do cultivo da bananeira é a falta de variedades comerciais produtivas, com porte adequado e resistentes a doenças. Além disso, a cultura também apresenta problema de disponibilidade de mudas em quantidade e qualidade para uma demanda de cultivo que vem aumentando significativamente nos últimos anos (OLIVEIRA et al, 2008a;COSTA et al, 2009).…”

“…Para a multiplicação e difusão acelerada dessas mudas tem-se utilizado a cultura de tecidos de plantas, que depende muito do estabelecimento de um protocolo seguro e que propicie uma alta taxa proliferativa das bananeiras in vitro (OLIVEIRA et al, 2008b). Assim, a cultura de células e a regeneração delas via embriogênese somática, constitui-se como uma técnica de grande aplicabilidade por permitir a obtenção de grandes quantidades de mudas com qualidade e com baixo custo de produção (MORAIS--LINO et al, 2008).…”