Morphological intraspecific variabilities in African yam bean ( AYB ) ( Sphenostylis stenocarpa Ex . A . Rich )

Intraspecific variabilities in 25 IITA accessions of African yam bean (AYB) (Sphenostylis stenocarpa Ex. A. Rich.) Harms were assessed through characterization of 36 morphological characters. The intraspecific variabilities among the accessions were evaluated by the following statistical analysis tools: Analysis of Variance (ANOVA), principal component and cluster analysis (Semi partial Rsquared method). The accessions showed significant differences in a number of morphological characters and the P values indicated significant differences (p 0.0001) in 27 characters. Statistical analysis showed that terminal leaflet length, terminal leaflet width, peduncle length, pod length, pod width, number of locules per pod and number of seeds per pod contributed significantly to seed set percentages in all the studied populations. Cluster analysis on the morphological data clustered the accessions into six distinct groups with pod and seed traits contributing significantly to the grouping. Pod lengths, number of seeds per pod and seed weight were observed to be useful characters for genetic improvement of AYB.