CBN-V Video Archives - S4-04
Towards a Densely Saturated Molecular Genetic Map of Cassava: Applying the DarT in the Development and Genome Location of Polymorphic DNA Fragments

Mba C., E. Gaitan, D.F. Cortes and J. Tohme

Biotechnology Research Unit, International Center for Tropical Agriculture (CIAT), KM17 Recta Cali-Palmira, AA 6713 Cali, Colombia
c.mba@cgiar.org

        Our Unit had developed an RFLP framework genetic map of cassava that we have recently substantially saturated with SSR markers. Current efforts are geared towards the enhancement of the utility of this map by further saturating it with more PCR-based markers, especially those that would be amenable to high throughput genotyping. This would in addition to fine mapping important traits, permitting rapid screening of cassava diversity also rapidly achieve a high throughput MAS. The progress made in the application of the Diversity Array Technology (DarT) in isolating and mapping polymorphic DNA fragments is presented here. We prepared a representative panel by cloning and individually arraying several thousands of DNA fragments from 4 cassava genotypes that are the parents of 2 mapping populations. PCR-amplified whole genomic DNA from these individual constituent members of the representative panel were labeled with Cy3 and Cy5 dyes, respectively, and in pairs were then hybridized onto the diversity panel. The polymorphic clones, i.e. the ones that fluoresce significantly differentially between these 2 dyes were isolated and used to screen the mapping populations and the segregation data used to place the polymorphic fragments on the framework map of cassava. The implications of the results are discussed.

For further information, see spoken presentation Mba, Fregene, Tohme S4-03.

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