Sweetpotato virus disease (SPVD) is a devastating disease due to the dual infection and
synergistic interaction of sweetpotato feathery mottle potyvirus (SPFMV) and sweetpotato
chlorotic stunt crinivirus (SPCSV). This study was conducted to: 1) determine the
inheritance of resistance to SPVD in sweetpotato; 2) estimate the nature of genetic variance;
and 3) evaluate methods for screening large populations for resistance to SPVD. The
genetic basis of resistance to SPVD was investigated in three studies. The first genetic
study consisted of a randomized block design at two sites in Uganda, during 1998-2000,
using 45 full-sib diallel (half) families of 10 parental clones varying in SPVD resistance.