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Interesting small mammal diversity is currently being uncovered in Nigeria, much of it through molecular analyses. The cytogenetic aspects of this diversity, however, remain largely unknown. In this study, diploid number and chromosome morphology viewed on Giemsa-stained slides for seven small mammal species trapped in Southwestern Nigeria are reported. The specimens were also sequenced for cytochrome b to assist in making accurate taxonomic designations. To our knowledge, chromosomal information is presented for four of these small mammal species for the first time from populations within Southwestern Nigeria. The respective diploid numbers detected in this study for Lophuromys sikapusiand Dasymyssp. differ from diploid numbers published for these species in previous studies. Cytochrome b sequencing helped us to correctly identify Mastomys erythroleucus(2n = 38), where specimens with this same chromosome number in our study area were erroneously assigned to other Mastomysspecies. Cytogenetic data combined with other lines of scientific evidence will help us appreciate and understand more the bountiful diversity of small mammals across Nigeria.

Multivariate analyses were carried out on fifty-nine germplasm accessions of cashew derived from both local and exotic populations established at the research plots of Cocoa Research Institute of Nigeria (CRIN), Ibadan, southwestern Nigeria, to assess the extent of variability and pattern of genetic diversity among these cashew populations. Data collected on 36 quantitative and 33 qualitative plant characters were subjected to taximetric tools of Euclidean distance of complete linkage (furthest neighbour) and principal component analysis (PCA). The multivariate analyses tentatively grouped the selections into four distinct morphogenetically diverse clusters. The groupings appear to be a function of origin, eco-geographical distribution, genetic and/or agronomic affinity of the selections. Brazilian populations distinctly clustered together in two major groups while local clones and Indian selections dominated the other two major clusters with each group having its unique fruiting and tree growth habits. The clustering pattern at sub-cluster levels clearly reflects affinity of each genetic population. The principal component analysis and the potency indices showed that fruit characters are the most discriminating parameters for delineating cashew at the varietal level.