Reversion from Sweet potato feathery mottle virus in bi-parental population of Naspot 11 and Beauregard

Abstract

Sweet potato is among the foods likely to contribute significantly to food security and hunger mitigation. Its production is constrained by several socio-economic, abiotic and biotic factors (Loebenstein and Thottappilly, 2009). Viral diseases are one of the most devastating biotic constraints in sweet potato production (Gutiérrez et al., 2003; Wambugu, 2003). Sweet potato feathery mottle virus (SPFMV) is of interest since it causes up to 50% reduction in yield (Gibson et al., 1997; Njeru et al., 2004). It and can also co-infect with Sweet potato chlorotic stunt (SPCSV) causing a severe sweet potato virus disease (SPVD) and yield reduction of up to 98% (Gibson et at., 1998).Breeding for resistance to virus infection is the most attractive approach to control viruses since it is economical and effecive. However, information is lacking if reversion from SPFMV infections is heritable in sweetpotato progenies of crosses between American varieties and East African landraces. To develop progenies from East African landrace NASPOT 11 and American variety Beauregard and to determine reversion from SPFMV of the progenies, the varieties were crossed and the resultant progenies tested for their ability to revert. The Biological indexing method of virus detection was employed using the indicator plant Ipomoea setosa. This involves grafting of the vine from the plant to be tested to susceptible indicator plants (Loebenstein et al., 2003). This was repeated on a bi-weekly basis for 8 weeks. Continuous bi-weekly observation and data collection was also done. The data acquired was analyzed for significance using repeated measures analysis of variance with XLSTAT software (Addinsoft, 2007). It was observed that there was a low number of seeds from the cross and this was attributed to a lot of incompatibilities in sweet potato crossing (Gurmu et al., 2013). The progenies were able to show significant reversion. This implies that this trait is possibly heritable. The reversion potential varied among the progenies and there replicates. The reversion potential was generally higher than the parent Beauregard with low reversion potential (Gibon et al., 2014: Adikini et al., 2016) and higher, similar or lower than that displayed by the parent Naspot 11 which has a high reversion potential (Gibon et al., 2014).