Microtuberización en Ñame (Dioscorea alata L.) var. "Pico de Botella"

Nodal “Pico de Botella” yam segments (Dioscorea alata L.) were cultured in tuberisation médium (TM) following Mantell and Hugo's technique (1989). This was supplemented with 0.1 mg/L thiamine, 100 mg/L myoinositol, 20 mg/L L-cystein, 1 g/L activated charcoal and 0.8% agar at pH 5.8 to evaluate the effects of the photoperiod (8 and 16 hours), sucrose (3, 6 and 9%), kinetin (0.0,1.5 and 2.5 μM) and abscisic acid (0.0,1.0 and 2.0μM) on micro-tuber production. A randomised split-plot experiment was carried out. Data analysed by ANOVA revealed that those factors evaluated had a substantial effect on micro-tuber induction, formation and development. The highest number of micro-tubers was obtained in an 8-hour photoperiod when treated with 1.5μM kinetin and 9% su- crose, whilst heavier micro-tubers were generally obtained in an 8-hour photoperiod with 9% sucrose in the absence of kinetin. The highest number of micro-tubers and greatest weight were presented by treatment involv ing an 8-hour photoperiod, 6% sucrose and 1.0 μM abscisic acid. Such treatment led to 235 micro-tubers being obtained, presenting 1.3 to 22.8 mm length and 2.3 to 217.4 mg weight. These results confirm the possibility of micro-tuber in vitro induction, representing great potential as commercial seed for yam growers and an additional tool for the cloned propagation of plants contributing to better handling and conservation of this cultivar´s germplasm. Segmentos nodales de Ñame (Dioscorea alata L.) variedad “Pico de Botella” fueron cultivados in vitro en medio de tuberización (MT) de acuerdo a Mantell y Hugo (1989) suplementado con 0.1 mg/L de Tiamina, 100 mg/L de Mioinositol, 20 mg/L de L-Cisteina, 1 g/L de Carbón Activado, 0.8% de Agar-Agar a un pH 5.8 para evaluar los efectos del fotoperiodo (8 y 16 horas), sacarosa (3,6 y 9 %), kinetina (0.0,1.5 y 2.5 μM, ácido abscisico (0.0,1.0 y 2.0 μM) sobre la producción de microtubérculos. Se realizó un diseño de parcelas subdivididas y organizadas completamente al azar, los datos se analizaron mediante un ANOVA; se encontró que todos los factores evaluados tienen un efecto substancial sobre la inducción, formación y desarrollo de los microtubérculos. En los tratamientos con kinetina el número más alto de microtubérculos fue obtenido bajo un fotoperiodo de 8 horas, 9% de sacarosa y 1.5 μM de kinetina; mientras que los microtubérculos de mayor peso fueron obtenidos generalmente a un fotoperiodo de 8 horas, 9% de sacarosa y en ausencia de kinetina. P