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Poster: Biology & Disease Mgmt: Genetics of Resistance


Identification of resistance genes and resistance gene analogs by si-RNA sequencing of the sweet potato leaf phytobiome
A. ALLEYNE (1), A. Alleyne (2), M. James (3), D. Gutierrez (4), S. Fuentes (4) (1) The University of the West Indies- Cave Hill Campus, Barbados; (2) The University of the West Indies-Cave Hill Campus, Barbados; (3) Ministry of Agriculture, Food and Water

Sweet potato (Ipomoea batatas L. (Lam) is affected by single and synergistic virus co-infections manifested as biotic stress and severe disease. Consequently, breeding for disease resistance is used in disease management. However, there are few reports of resistance genes (R-genes) against specific viruses in sweet potato virus disease complex (SPVD). This study sought to identify R- genes in the sweet potato leaf phytobiome using Next Gen-sequencing. RNA-seq has been used to characterize viruses causing SPVD while discovery of R-genes traditionally involves cloning and characterization of resistance proteins and resistance gene analogs (RGA). In this study, RNA was extracted from three sweet potato cultivars (CBS 49, CBS 32 and C-104) symptomatic with Sweet potato feathery mottle virus (SPFMV), Sweet potato leaf curl virus (SPLCV) and Sweet potato badnavirus A and B. These were then subjected to RNA-seq analysis and bioinformatics analysis of the assembled contigs for resistance genes. We report the presence of transcripts of a total of thirty-one such genes, and putative proteins representing several classes of resistance genes including nucleotide-binding site leucine-rich repeat (NBS-LRR) and RGA from sweet potato such as AB125881, DQ903328, and DQ903597 in the sweet potato phytobiome. These results provide a genome resource of R-genes for development of tagged molecular markers useful for mapping disease resistance in specific sweet potato cultivars.