Different levels of ploidy as a strategy for control of dry root rot in tanier (Xanthosoma spp.)

Abstract

The objective of this study was to evaluate the level of tolerance or susceptibility of different cultivars of tanier (Xanthosoma spp.) to root rot caused by Sclerotium roifsii, Rhizoctonia solani, Fusarium solani, Pythium sp., two pathogenic bacteria, and the combination of all the above mentioned pathogens associated with the disease. Under greenhouse conditions, we studied tanier cultivars with different levels of natural and induced polyploidy.The cultivars used were Palma, natural tetraploid (2n = 52); Venezolana, natural pentaploid (2n = 65); Amarilla del País, artificial tetraploid induced with coach (2n = 52); and Amarilla del País, natural diploid (2n = 26). The artificial tetraploid developed from Amarilla del Pais showed the highest percentage of root rot for all the pathogen treatments, higher than that of the natural diploid from which it was originated. The cultivars Palma and Venezolana showed a lower percentage of infection than cultivar Amarilla del País (tetraploid).