ABSTRACT

 The productivity of sweetpotato (Ipomoea batatas (L.) Lam.) is mainly dependent on the acquisition of genotypes which posses desirable traits and development of high yielding varieties with desired quality attributes. For this purpose, a field experiment was carried out at the National Root Crops Research Institute, Umudike, Nigeria, to characterize and evaluate the level of diversity within and across eight different sweetpotato families (Ligri X Sauti, Sauti X 442162, Ligri X Faara, Ligri X Apomoden, Sauti X Bohye, Sauti X Ligri, Ligri Poly cross and Sauti Poly Cross). A total of one hundred and forty one sweetpotato genotypes obtained from eight different families of sweetpotato seeds sourced from the International Potato Center, Kumasi, Ghana were used for this research work. The sweetpotato families which were poly-cross (half-sib) and controlled cross (full-sib) were characterized morphologically using International Potato Centre (CIP) descriptors. The study was conducted during the 2015 and 2016 cropping seasons to characterize and evaluate agronomic attributes of the sweetpotato genotypes. The 141 genotypes and two checks (UMUSPO3 and TIS87/0087) were laid out in an augmented design. Varied numbers of genotypes recorded significantly higher values than the mean ofthe checks for days to physiological maturity, storage root fresh weight/plant, total storage root yield, marketable storage root yield. However, non significant differences were observed between genotypes for unmarketable root weight. Ligri PC/17 had the highest storage root yield in 2015 cropping season, while Sauti X Bohye/8 had the highest storage roots yield in 2016 cropping season. Most of the genotypes had pink skin color 58% and 55% for both full-sib and half-sib families respectively while 34% of the genotypes had creamy flesh color for both full sib and half sib families. The cluster analysis revealed that all the genotypes belonging to the different eight families were grouped into 4 different classes based on the morphological and yield related attributes. Principal component analysis showed presence of variations among genotypes for considerable number of traits and the possibility of selecting genotypes for further breeding objectives. Findings would also be useful for conservation planning of sweetpotato using molecular techniques to confirm the variations observed