Cassava

Se indican las actividades de investigacion relacionadas con biotecnologia en yuca. Existe una base solida para un proyecto futuro de elaboracion de mapas moleculares del genoma de yuca. Se ha seleccionado un grupo basico de marcadores polimorfos de bancos genomicos de yuca; el siguiente paso es la generacion de un mapa de ligamiento utilizando estos marcadores. Tambien se ha regenerado yuca de embriones secundarios formando callo embriogenico a partir de meristemas apicales; esto es el punto de partida para los expt. de transformacion utilizando Agrobacterium y bombardeo de particulas. En relacion con la fermentacion de almidon de yuca, se ha investigado la caracterizacion de las actividades amiloliticas microbianas involucradas en el proceso. En relacion con los conocidos mecanismos de adaptacion de la yuca en cuanto a limitaciones climaticas como sequia y calor, sin perder productividad, se estudia la posible compartamentalizacion de enzimas fotosinteticas foliares mediante hibridacion in situ, utilizando sondas genicas marcadas. Se encontro un alto grado de homologia entre genes fotosinteticos de yuca mediante tecnicas de hibridizacion. Ahora se esta generando un banco genomico de yuca. (CIAT)

Research activities related to biotechnology in cassava are indicated. A solid basis has been worked out for a upcoming project of the molecular mapping of the cassava genome. A basic set of polymorphic markers from cassava genomic libraries has been selected; the generation of the linkage map using these markers follows. Cassava has also been regenerated from secondary embryos forming an embryogenic calli stemming from apical meristems, which is the target issue for transformation expt. using Agrobacterium and the particle gun. Regarding cassava starch fermentation, work has been carried out on the characterization of microbial amylolytic activities involved in the process. Regarding the known adaptation mechanisms of cassava for dealing with climatic constraints such as drought and heat, without losing productivity, the possible compartmentalization of photosynthetic enzymes in the leaf by in situ hybridization, using labelled gene probes, is under study. A high degree of homology has been found between maize and cassava photosynthetic genes by hybridization techniques. A genomic cassava library is now being generated. (CIAT)