Germplasm characterization and evaluation are essential for the genetic improvement of crops. In this study, a collection of 204 groundnut accessions including 13 checks held by Plant Genetic Resources Research Institute, Ghana were evaluated under optimal conditions for 2 years. The objectives were to characterize the groundnut collection using 18 qualitative and 14 quantitative traits and to determine the relationships between the traits. Combined analysis of variance based on augmented design revealed significant differences (P < 0.05) among the accessions for majority of the traits. Results of principal component analysis showed that all the quantitative traits were relevant in discriminating the accessions. Primary seed colour was the most diverse qualitative trait based on Shannon diversity index (n = 0.77). Frequency distribution analysis showed predominance of decumbent growth habit and pale tan seeds. Cluster analysis using qualitative traits identified five major groups of accessions and three each based on quantitative traits and joint analysis of quantitative and qualitative traits. Number of main branches (NMB) and pod width (PW) appeared the most important traits with positive contribution to yield based on correlation and path coefficient analysis. Ten promising trait-specific accessions were identified for earliness along with desirable pod and seed traits. GH 9672 and GH 9665 were identified as promising for higher grain and fodder yield. Five accessions (GH 9833, GH 9829, GH 9830, GH 9835 and GH 9750) produced ~5–30% more grain yield than the best check. This study underscored ample phenotypic variation that would ultimately be exploited for genetic improvement of groundnut.

International Institute of Tropical Agriculture maintains 2544 cassava accessions (Manihot esculenta Crantz) from 28 countries in its field bank. Being vegetatively propagated, this poses challenges in maintenance in terms of cost as well as in labour requirements. A core collection representing the range of phenotypic diversity present in the entire collection would enhance the conservation aspects and increase the potential for its exploitation in crop improvement programmes. The present study aimed to establish a core collection using 40 agro-morphological traits evaluated at two locations using a different number of accessions in each location. To meet the challenges generated by the types of variables and include maximum diversity in the core collection, a sequential strategy based on five major concepts was used: hierarchical multiple factor analysis allowing the mixture of variables of different kinds; three-way analysis that included the effect of genotype × environment interaction in the clustering process; linear discriminant function to assign all those individuals who were included in one location but not in the other to the groups that were generated from the common number of accessions evaluated in both locations; and D-allocation method to select samples from each cluster. The representativeness of the core subset to the entire collection was further estimated by comparing means and variances, range, and distances between accessions. The established cassava core collection consisted of 428 accessions that conserved 15% higher phenotypic diversity with no redundancies. The phenotypic diversity represented in this core collection will be a guide to users of cassava germplasm in their crop improvement programmes.