Seed yield of selected Nigerian Bambara Groundnut landraces under two varying water conditions was evaluated. Twenty eight (28) Bambara groundnut accessions were planted in a randomized complete block design with two treatments (Nonwater stressed and Water stressed) and replicated five times. The experiment was conducted at the Experimental Garden of the Department of Biological Sciences, Federal University of Technology, Minna, Niger State. The accessions were planted in planting bags during the cropping season of 2016 between July and October. The two treatments were rain fed until maturity except during the period of exposure to water stress where the water stressed plants were transferred to a screen house made with polyvinyl ceiling to prevent water during the flowering stage for two weeks. It was observed that water stress reduced the yield of the Bambara groundnut landraces by 47%. Accessions NGB-01646-B, NGR-NI-20-H and NGB-01491 which had relatively high yield in the stressed and non-water stressed condition were considered the most drought tolerant accessions and accession NGR-KG-02-C with low yield both in stressed and non-stressed conditions was identified as the most susceptible accession. Accessions which had high yield only in water stressed conditions could serve as elite line for Bambara groundnut for areas which have problem of drought. These drought tolerant accessions identified in the research can serve as potential parent lines in breeding programmes aimed at the development of drought tolerant varieties of Bambara groundnut.

In order to assess the genetic diversity of Roselle (Hibiscus sabdariffa L.) in Nigeria, a survey was undertaken to collect the germplasm of the crop. The survey cut across 56 towns and 20 villages in 17 states including the Federal Capital Territory (FCT). Sixty three (63) farmers were interviewed and 60 accessions of Roselle were collected from them. Results showed that 41.7% of these accessions were having green calyx, while 31.7% were with red calyx. On the other hand, 20.0% of the accessions possessed deep red calyx while only 6.7% have light red and pink calyx. Collections from the North Central, North Eastern, North Western and South Western parts were replicated over states, towns and villages. The highest number of Roselle accessions was collected from Kaduna State (8 accessions) followed by Niger State (6 accessions); Jigawa State (6 accessions) while FCT and Bauchi State have 4 accessions each. This is an indication that these areas have the greatest diversity of the crop genetic resources in Nigeria and the states might be secondary centre of origin of the crop. However, morphological as well as molecular characterizations are required to arrange the Roselle accessions collected into a suitable group; this will eventually provide the raw materials needed for the Roselle improvement programme in Nigeria.

Castor oil plant (Ricinus communis L.) is an important oil crop with little research attention in Nigeria. In the present research, extent of genetic diversity among 20 Nigerian castor genotypes was determined using morphological descriptors and molecular markers. The genotypes were laid out on a randomized complete block design with three replicated plots. Molecular genotyping of the genotypes was carried out using genomic Simple Sequence Repeats (SSR). The genotypes revealed high divergence in seed colour, seed shape, seed mottle, seed caruncle and seed sizes. Seedling establishment varied from 70.18% (in Acc. 006) to 93.25% (Acc. 001) with average mean of 81.53%. Raceme length ranged from 15.90 cm to 29.54 cm with population mean of 20.80 cm. The highest seed yield (1222.98 kg/ha) was recorded in Acc. 001 and the least (611.46 kg/ha) was observed in Acc. 006. Seed oil content varied between 32.15% in Acc. 042 and 54.03% in Acc. 006. Agglomerative cluster dendrogram constructed from morphological data showed random distribution of the genotypes into three cluster groups irrespective of the sources/collection points. The genetic diversity based on SSR Marker Analysis revealed high average expected heterozygosity (0.74), Polymorphic information content (0.68), Nei’s gene diversity index (0.72) and Shannon's Information index (1.43). The dendrogram constructed from molecular data grouped the twenty genotypes into three groups at coefficient of 0.34. From these findings, it showed that the twenty genotypes evaluated are divergent in nature and they could serve as good genetic material for castor breeding in Nigeria.

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Estimates of some pollen parameters where used to assess the genetic diversity among some newly selected Nigerian Roselle (Hibiscus sabdariffa L.). Standard procedures were used to determine the pollen parameters such as: percentage pollen fertility, percentage pollen sterility, pollen diameters as well as anther diameters. The cytological results revealed significant (P ≤ 0.05) variation in the diameters of anther cap and pollen grains. Anther morphology and pollen grain morphology of the H. sabdariffa genotypes under light microscope showed fair diversity in the Anther and pollen grain sizes. The Roselle genotypes were grouped according to their anther sizes into small (< 400 μm), medium (400-700 μm) and large (> 700 μm); such character should be included in examining genetic diversity in this crop. The dendrogram produced from the cluster analysis of the different genotypes of the roselle based on diameters of the pollen grains and that of the anther cap-sizes also separate the genotypes into different groups. The results obtained in terms of percentage pollen fertility also showed some interesting variations. It is not untrue that larger pollen grain could serve as a better pollinizer than a smaller pollen grain; moreover, successes in crossing among such plants could be dependent on the sizes of the pollen. The pollen grain size variations obtained from this study is of good taxonomic value. The variation in the anther and pollen grain sizes could also be as a result of different genetic make of the Roselle genotypes and could serve as important diagnostic tool in differentiating Nigerian Roselle genotypes and achieving the cytotaxonomy of the crop. It is therefore concluded that there exist genetic variability among the pollen grains and anthers of the new selected Nigerian Roselle (H. sabdariffa) genotypes; these characters are good taxonomic parameters that could be used in evaluating genetic diversity of the crop in the study area. It is recommended that other pollen viability staining techniques should be employed to ascertain the level of the pollen fertility among the Roselle Genotypes. In addition, DNA-PCR technique should be used to further confirm the variability observed in this present study.