Screening of sweetpotato genotypes for resistance to sweetpotato virus disease in Uganda
Abstract
Sweet potato is a major food crop in eastern and southern African countries. Production of sweetpotato is constrained by sweet potato weevils and sweet potato virus disease (SPVD). Previous research at National Crops Resources Research Institute, Namulonge (NaCRRI) selected eight (8) sweet potato parental clones that exhibit variations in resistance to sweet potato weevils, and these are New Kawogo, Osapat, Anyina, New Dimbuka, Tanzania, Beauregard, Tedelokeren and NKB 257. These eight parental clones were crossed in a half diallel mating design to generate 28 full-sib families but due to high level of incompatibility
and poor germination of seeds, only 27 families were generated. The aim of this study was to evaluate available genotypes for SPVD resistance. The performance of the diallel population (202 F1 genotypes) and eight parents for resistance to SPVD, dry matter content, vine weight and total root yield was assessed at NaCRRI. Results indicated a significant difference (p<0.001) among the genotypes for all the traits studied. Most of the genotypes including the parents were susceptible to SPVD. Genotype NDTZ-6 and NKOS-11 were, however, more resistant than local checks Anyiina, Tedelokeren, Beauregard. Osapat and New Dimbuka were selected for high root yield. NDTZ-6 and NKOS-11 was selected for SPVD resistance, and recommended for planting in other agro ecological zones for Genotype by Environment interaction and also as potential parents for further sweet potato breeding work.