ABSTRACT

 Sweet potato (Ipomoea batatas (L) Lam) is one of the most important root crops in the world, particularly in sub-Sahara Africa. Collecting and characterizing plant material has been the basis for crop improvement, Diversity studies has long been seen as vital for rational management and use of crops. Thirty-two newly developed clones (progenies) and their parents [Tis 8164 (Ml), Centennial (F2), Umuspo 3 (mother delight) Fl, Umuspo 2 (M3) and Tio Joe (F5)]were obtained from sweet potato breeding program of National Root Crops Research Institute Umudike and planted at western farm of the Institute , replicated three times in randomized complete block design and characterized to determine the expressions of character using International Potato Centre (CIP) descriptors. Eighteen (18) morphological characters were used [Plant growth characteristics: plant type (PT), ground cover (GC); mature vine characteristics: vine internode length (VIL), predominant vine colour (PVC), secondary vine colour (SVC), vine tip pubescence (VTP); mature leaf characteristics: general outline of leaf (GOL), leaf lobes number (LLN), mature leaf size (MLS), shape of central leaf lobe (SCLL), mature leaf colour (MLC), immature leaf colour (ILC); flowering habit (FH); Storage root characteristics: predominant skin colour (PSC), secondary skin colour (SSC), predominant flesh colour (PFC), secondary flesh colour (SFC), distribution of secondary flesh colour (DSFC) and storage root shape (SRS)]. This study therefore sought to morphologically characterize the selected progenies; to identify those important descriptor traits that contributed most to the observed variation among all the progenies. Also, to determine the progenies that are parent-like and to evaluate the progenies that are less susceptible to sweetpotato virus disease (SPVD). The data generated were analyzed . for morphological diversity using principal component analysis (PCA), which was used in identifying the few characters that significantly influenced the observed variation among the progenies. In summary, this study revealed that ground cover, vine internode length, predominant skin colour, secondary skin colour, flower colour, flower habit, mature leaf, leaf lobe type and leaf lobe number were important descriptor traits in segregating sweet potato and also indicated progenies and parents that were less susceptible to SPVD for breeding purposes and, to farmers for a good yield