Studies on Beauregard sweetpotato clones naturally infected with viruses

Abstract

The response of clonal sweetpotato naturally infected with viruses was investigated. Analyses included yield, canopy biomass, and root colour on twelve virus infected (V + ) clones and corresponding virus-tested (V−) mericlones (clones derived from meristem-tip culture) of ‘Beauregard’ sweetpotato. All V + clones tested positive for Sweet potato feathery mottle virus and some clones additionally tested positive for Sweet potato virus G (SPVG) and/or the newly identified Ipomoea vein mosaic virus (IVMV). The V− mericlones had greater marketable yields for the important US No. 1 grade in three of four plantings in comparison to their V + clonal counterparts. Comparisons within V− mericlones did not show significant yield differences, suggesting clonal variation was minimal in this randomly selected set of ‘Beauregard’ mericlones. Canopy vine weight was lower overall in two of three plantings for V + clonal variants in comparison to their V− mericlones. Skin and flesh was redder and more yellow in V− mericlones in comparison to their V + clonal counterparts, cumulatively resulting in a deeper orange tissue. Our results from mericlone comparisons suggest that clonal variation was minor on general agronomic traits of ‘Beauregard’ sweetpotato and that variation in yield, canopy, and root coloration among V + clones and V− mericlones was mostly a function of virus infection.