Abstract

VASQUEZ, Andrea  and  LOPEZ, Camilo E. Identification of polymorphisms in resistance gene candidates in cassava (Manihot esculenta Crantz). Acta Agron. [online]. 2012, vol.61, n.2, pp.133-142. ISSN 0120-2812.

Cassava production can be detrimentally affected by diseases caused for different pathogens. To defend against viral, bacterial and fungal diseases, plants have developed a group of resistance proteins (R), which are able to recognize pathogen’s molecules. A wide repertoire of R proteins has been identified in a large group of plants. Even though conferring resistance to different pathogens, these R proteins have a few conserved domains. Taking advantage of the recent release of complete cassava genome sequence, we identified cassava R-like proteins in this genome. With this information, primers were designed to amplify 13 genes showing similarity to known R genes. For 10 of them we obtained amplification in the varieties TMS30572 and CM2177-2, which represent the parents used in the construction of the cassava genetic map. After sequencing the amplicons obtained, we identified 37 SNPs (Single Nucleotide Polymorphisms) between these two cassava varieties, which represent 18 (48.6%) transitions and 19 (45.9%) transversions. The remaining are insertions/deletions (indels). This knowledge will help to develop appropriate strategies for the generation of CAPs (Cleaved Amplified Polymorphisms) markers to assess their segregation in the F1 population, allowing the localization of these markers on the cassava genetic map.

Keywords : Cassava; genetic maps; genomes; Manihot esculenta; molecular markers; resistance..

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