RESUMO
Bananas (Musa ssp.) are among the world's most important crops. In terms of gross value of production, they are the fourth most important global food crop and have an important socioeconomic and ecological role. Somatic embryogenesis (SE) is a developmental process, in which somatic cells differentiate into embryos which eventually develop and regenerate into plants. SE is exploited to generate a large quantity of very high economic value, genetically identical and disease-free plantlets. In bananas, the use of shoot apexes of axillary buds to induce SE resulted an alternative for plant regeneration through embryogenic cell suspension (ECS). The protocol has been scaled up to commercial laboratories for tissue culture (biofactories) for production of planting materials. The genetic stability of regenerated plants and high yields obtained under field conditions demonstrate the feasibility of scaling up this biotechnological protocol and adapting it to commercial production of planting materials to mitigate a critical bottleneck in the value chain of this important crop.
Assuntos
Musa , Desenvolvimento Embrionário , Musa/genética , Técnicas de Embriogênese Somática de Plantas/métodosRESUMO
El mantenimiento en campo de los Bancos de Germoplasma resulta muy costoso, además de los riesgos a que se exponen. El cultivo de tejidos constituye una solución a estos problemas siendo conveniente utilizar una combinación de técnicas de almacenamiento en los cultivos de propagación vegetativa para no depender de una sola. El cultivo in vitro ofrece nuevas alternativas para el mejoramiento de la productividad y la producción de material de siembra sano en malanga (Xanthosoma spp.). La presente investigación se desarrolló en el Laboratorio de Cultivo de Tejidos del Instituto de Investigaciones de Viandas Tropicales (INIVIT), Cuba, con el objetivo de estudiar las condiciones para la conservación en crecimiento mínimo in vitro de germoplasma de esta especie. Como material vegetal se utilizó el clon de Malanga Xanthosoma "INIVIT MX-2008". El establecimiento del material vegetal y su posterior multiplicación fueron realizadas según la metodología recomendada por García et al. (1999). Para la conservación en medio de cultivo de crecimiento mínimo se utilizó el medio basal MS y se estudiaron 15 tratamientos que combinaron concentraciones de Manitol (regulador osmótico) (1,5; 3 y 4%) y Nitrato de plata (inhibidor de la acción etileno) (0, 2, 4, 8, 10 mg.L-1). Se concluye que es posible conservar in vitro los recursos genéticos de malanga Xanthosoma durante más de 10 meses, en un medio de cultivo compuesto por sales y vitaminas MS suplementado con 4% de manitol y 4 mg.L-1 de Nitrato de plata. Las plantas propagadas a partir de este medio de cultivo se recuperaron exitosamente. La mayor concentración de manitol en el medio de cultivo pudo haber influido en la mejor recuperación del material conservado.
Maintenance field genebanks are costly, in addition to the risks they face; to that effect on tissue culture is a solution to these problems. In vegetative propagated crops is desirable to use a combination of storage technology rather than relying on just one. in vitro culture provides an alternative for improving productivity and production of healthy planting material of taro (Xanthosoma spp.). This research was conducted in the Tissue Culture Laboratory of the Research Institute of Tropical Crops. Our objective was study the conditions for minimal growth conservation in vitro germplasm in this species. As plant material was used clone of Taro Xanthosoma 'INIVIT MX-2008'. The establishment of the plant material and its subsequent multiplication were carried out according to the methodology recommended by García et al. (1999). For the maintenance in culture of minimal growth basal medium MS was used and studied 15 treatments with combined concentrations of mannitol (osmotic regulator) (1.5, 3 and 4%) and silver nitrate (Ethylene inhibitor) (0, 2, 4, 8, 10 mg.L-1). It concludes that it is possible to conserve taro Xanthosoma genetic resources in vitro, for over 10 months in a culture medium composed of MS salts and vitamins and supplemented with 4% mannitol and 4 mg.L-1 of silver nitrate. Plants propagated from this culture medium were recovered successfully. The presence of higher concentrations of mannitol, may have influenced that increases survival of preserved material. O3.
