A field experiment was conducted at Department of Agricultural Research in Sebele in the 2012 to 2013 season using nine accessions that were sourced from the National Plant Genetic Resource Centre (NPGRC), Gaborone, Botswana. Multivariate statistical procedures such as clusters and principal component analysis were used on 15 selected characters to assess agro-morphological variability among tepary bean landraces collected in Botswana. Few characters were statistically significant which suggest lower genetic diversity among the Botswana tepary beans. The first three PCA accounted for 77.12% of accumulated variation. Traits which revealed significant contribution to variation among accessions were number of leaves, plant spread, pod width, 100 seed weight and seeds per pod. The dendrogram results also showed that these characters contributed significantly to the grouping of accessions into three clusters. Three accessions GK011, MTS (Motsumi) and GK012 were separated from the rest of the accessions. However, GK012 and MTS (Motsumi) with highest number of valuable traits are recommended for plant breeders to use as parents in future breeding programs.

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Characterization of cowpea (Vigna unguiculata[Areas not yet explored and those that need additional sampling were identified. The study demonstrated a significant amount of diversity among the germplasm based on the analysis of variance (ANOVA) and Shannon Weaver Diversity Index (H'). The majority of accessions had their first flowering more than 50 days after sowing and 100 days for 95% of maturity which shows that they are more inclined towards late maturing cowpeas. Early maturing accessions with less than 110 days to maturity are found in Ngamiland, Southeast and unknown origin. The accessions from Central districts had the largest variation for most characters (11) followed by Southeast with 10 among the 22 quantitative characters evaluated. Principal components analysis (PCA), revealed characters which discriminated more efficiently between accessions than others such as peduncle length, 10 seeds weight, seed width, seed thickness, pods per peduncle, and 100 seed weight. Cluster analysis delineates germplasm into three clusters, based on the origin of the germplasm according to different agro-ecological zones. Germplasm accessions originating from Ngamiland formed a separate cluster from the rest and had several peculiar materials, which could be a potential source for new germplasm for cowpea improvement. Further molecular studies are required to complement and validate the current agromorphological variation observed in the Botswana cowpea germplasm.

Jatropha curcas L. is an undomesticated plant species that has recently received great attention for its utilization in biofuel production in many countries including Botswana. The experiment investigated 30 J. curcas accessions, and the results revealed high significant differences (P<0.01) among accessions for peduncle length, number of seed per fruit, length of fruit stalk, fruit length, fruit width, seed length, seed width, seed weight, leaf length, leaf width, petiole length, total flower per cluster, female and male flower per cluster, and number of fruit per cluster. The qualitative characters revealed substantial amount of variability among the accessions except in fruit shape, stem color and flower color. Multivariate cluster analysis based on morphological characters and molecular characterization grouped the accessions into four clusters at dissimilarity coefficient of 1.37 and 0.85, respectively. The clustering based on morphological characters slightly matched that of groupings derived through molecular analysis with group A and B having some similar accessions. One Ghana accession used as reference was clearly separated from other accessions by both morphological and molecular markers, and also by seed weight and inflorescence compactness. Eight morphological characters and six molecular markers correlated positively with correlation coefficient values ranging from 0.56 to 0.66.

Jatropha (Jatropha curcas L.) has been identified as a potential bioenergy feedstock in arid regions, but knowledge of the diversity of its chemical characteristics is limited. In this study, 61 Jatropha accessions growing in Botswana, where both severe drought and winter frosts frequently occur, were analyzed for their seed chemical properties. Histogram analyses and meta-analysis comparisons with seeds from other countries/continents showed that the median/mean dry seed weight, toxic compound phorbol esters, and C18:0 fatty acid levels in the Botswanan accessions were lower than those from other countries/continents. A clustered heat map analysis indicated five clades for the Botswanan accessions, and their physicochemical traits were also categorized into five groups. Many positive and negative correlations were observed among the chemical traits, including negative correlations between the C18:3 (linolenic acid) content and yield-related traits (lipid content and dry seed weight). Principal component analysis highlighted the existence of accessions with highly deviated seed chemical compositions, such as those enriched in C18:0/C18:1 and C16:0/C16:1/C18:3 fatty acids. Overall, the present study suggests considerable diversity in the seed chemical compositions of Botswanan Jatropha accessions. Various accessions could be useful as feedstock for specific industrial products, as well as for breeding materials for the fortification of specific chemical ingredients.