Search

Arrow cane (Gynerium sagittatum Aubl.) is a Poaceae associated to human development of the ancient Zenú culture present nowadays in the flat lands of Córdoba and Sucre department in the Colombian north Coast. Despite its importance, arrow cane is not cultivated in large scale and extraction from natural populations is the most common way for plant exploitation with negative environmental and economic consequences for the aboriginal communities. A research program based on biotechnology was implemented to generate information related to plant genetic diversity, plant propagation and genetic resource conservation in order to provide knowledge to contribute to implement technical crop development to minimize the impact of artisans´ activity on the environment and increase sustainability on fiber source for craftsmanship. Accessions from different zones of the Colombian territory were characterized using morphological and molecular markers founding low genetic diversity. Cultivars UC121, “Criolla”, “Criolla 1”, Costera and “Martinera” were in vitro established and micropropagation results indicated that large quantities of high quality, fully adapted, homogeneous plants can be produced from any cultivar. In vitro cultured arrow cane plants can be stored by means of slow growth or modified structures such as micro rhizomes developed in vitro.

To reduce costs associated to ex vitro adaptation of arrow cane (Gynerium sagitatum Aubl.) plants Cv “Criolla”, the effect of three substrate mixes (Peat, peat + river sand and peat + rice husk) on survival, plant height and substrate associated plant cost were evaluated. Plants were micropropagated in semisolid MS medium supplied with 0,5 mg L-1 BAP. After medium removal, plants were transferred on 72-plug plastic trays filled with the respective substrate treatment. Trays were covered with translucent plastic covers during three days. Thereafter, plants were maintained in a 50% light shade house, fog irrigated twice a day for 1 minute each during 8 weeks. Treatments were distributed with a block randomized design. Data were analyzed with ANOVA and means were separated with Tukey´s mean separation test. Results allowed to evidence that peat + sand resulted in significant increase in survival, plant height and >35 decrease in substrate associated plant cost during adaptation to ex vitro conditions.

Gynerium sagitatum Aubl. (Poaceae) is an important environmental, cultural and economic species for aboriginal communities in Northern Colombia, in which the centrale central nerve is used to make precious craftsmanship products. The massive use of the plant with no restoration has dangerously decreased natural populations. Micropropagation has emerged as a way to efficiently produce planting material for cropping and restoration of affected areas. To improve cost efficiency of the micropropagation protocol, in vitro rhizome structures were induced using in vitromaintained plants as explants under three quantities of sucrose, four of benzyl aminopurine - BAP and four of abscisic acid - ABA supplied in MS with (in mg L-1) myo-inositol (100), thiamine HCL (0.4), and solidified with Phytagel® (3.000). Treatments (48) were distributed using a complete randomized design with six replicates per treatment. Cultures were stored during eight weeks at 25 °C with 12 h photoperiod (40 μmol photons m-2 s-1) provided by with cold fluorescent lamps. Statistical differences were observed with respect to number of rhizomes and rhizome length as a result of three factor interaction. Ex vitro plantlet recovery occurred at highest percentage from rhizomes developed in media supplied with sucrose at 263000 µM combined with 4.44 and 8.88 µM BAP. Data evidenced the possibility of inducing in vitro rhizome growth from arrow cane explants to use them as a way for propagation and plant conservation.

Con miras a contribuir con el desarrollo de un protocolo para la regeneración de plantas de batata (Ipomoea batatas (L.) Lam.) vía embriogénesis somática, se evaluó la capacidad de inducción y proliferación de tejidos celulares a partir de diferentes explantes (lámina foliar, pecíolo y la lámina foliar con el pecíolo adherido) establecidos en medio semisólido Murashige y Skoog (MS) suplido con (mg L-1) tiamina HCl (1,0), sacarosa (30.000), myo-inositol (100), agar (7.000) y cinco concentraciones de 2,4-D (0,0; 2,26; 4,52; 9,04 y 18,08 µM). La proliferación del tejido se evaluó en medio semisólido MS y MS3:1N líquido utilizando un diseño completamente al azar. Se determinó que el suministro de 2,4-D en el medio fue necesario para observar inducción en explantes de batata, el mayor porcentaje de inducción de tejido se observó cuando se utilizó la lámina foliar con el pecíolo adherido como explante. La inducción de tejido se evidenció a partir de las semanas seis y siete con tejidos de coloración amarillo-crema y consistencia compacta creciendo de los explantes. Se lograron tasas significativas (Pr menor o =0,05) de proliferación en medio semisólido y en medio líquido por efecto de la adición de 2,4-D.

La producción y exportación de ñame se han visto afectadas negativamente en las últimas décadas como consecuencia de la incidencia de antracnosis, la cual se ha manejado con genotipos con algún grado de resistencia, sin alcanzar un manejo eficiente de está. Con el fin de contribuir en el mejoramiento genético del Dioscorea alata se evaluó la respuesta de cultivos embriogénicos de ñame al hongo Colletotrichum gloeosporioides y a su filtrado. Cultivos embriogénicos fueron inducidos a partir de explantes foliares de la variedad “Pico de botella” en presencia de 2,4-D. Las masas proembriogénicas (MPEs) obtenidas fueron multiplicadas y posteriormente expuestas a diferentes concentraciones del filtrado, al igual que establecidas en forma de un cultivo dual entre éstas y una muestra de micelio del hongo. Ambos experimentos evidenciaron un alto grado de susceptibilidad de los tejidos inducidos a la presencia del hongo.