Browsing by Author "McBenedict, Billy M."

Now showing 1 - 2 of 2
  • Thumbnail Image
    Item
    Bacteriological analysis of household water from hand-dug wells in the Cuvelai-Etosha basin of Namibia
    (University of Namibia, 2017) McBenedict, Billy M.; Wanke, Heike; Hang' ombe, B.M.; Chimwamurombe, Percy M.
    Communities in Oshikoto, Omusati, Ohangwena and Oshana regions of Namibia widely utilize the Cuvelai-Etosha Basin by constructing hand-dug wells to provide water to sustain agriculture and households. Since these regions lack a developed water pipeline system and deeper ground water maybe saline in large parts of the Basin, people rely on domestic water supply from private hand-dug wells which are near their houses for convenience and preference. However, the microbial water quality and safety of hand-dug wells being utilized for household consumption in the Cuvelai-Etosha Basin is unknown and this is undesirable since water is a habitat for some pathogenic microorganisms there by posing a health risk. Thus, a bacteriological water quality study that focuses on the identification of microbial contaminants was conducted on 25 wells in the Cuvelai-Etosha Basin of Northern Namibia during two sampling campaigns. Molecular methods indicated the presence of Bacillus aerophilus, Bacillus amyloliquefaciens, Bacillus aquimaris, Bacillus aryabhattai, Bacillus cereus, Bacillus licheniformis, Bacillus pumilus, Bacillus safensis, Bacillus samanii, Bacillussp.M37,Bacillussp. M26, Bacillus stratophericus, Bacillus subtilis, Pseudomonas mendocina, Staphylococcus haemolyticus and Streptomyces celuloflavus.
  • Thumbnail Image
    Item
    The genetic diversity of Pennisetum Glaucum (L.) R BR. (Pearl Millet) Landraces in Namibia
    (University of Namibia, 2015) McBenedict, Billy M.
    The current Pennisetum glaucum (L.) R. Br. cultivars in Namibia have overall poor performance and this poses a threat to the nation's food security because this crop is staple for over 70% of the Namibian population. The crop suffers from a range of undesirable production traits such as; susceptibility to diseases, low yield and prolonged reproductive cycle due to lack of genetic diversity. This study was aimed at understanding the genetic diversity of the crop in Namibia by means of Internal Transcribed Spacer (ITS) sequence data analysis, and SSR and RAPD techniques, and evaluating the most informative technique of the three. A total of 1441 genotypes were collected from the Gene Bank representing all the Namibian landraces. Samples of 96 genotypes were further analyzed using the Shannon-Wiener diversity index and revealed values of 0.45 for SSR and 0.7 for RAPD indicating low genetic diversity. Ordination results using Principal Coordinate Analysis (PCoA) for RAPD, morphology and SSR data confirmed the same clusters as generated by Un-weighted Pair Group Method with Arithmetic Mean (UPGMA) for the same data sets. UPGMA generated phenograms of 29 morphological characterized genotypes were generated for SSR, RAPD and morphology data. The ITS sequences of the same 29 accessions were used to construct a phylogenetic tree. This tree revealed clades with highest similarity with the phenogram generated from morphology (78%) data, followed by the SSR data (68%), and lastly the RAPD (50%) data. Lodging susceptibility, tillering attitude, spike density, bristle length, fodder yield potential, early vigour, number of nodal tillers and spike shape were identified as the phenotypic characters upon which some clusters were based in all data sets used. It is recommended that efforts be made to widen the available gene pool in order to increase genetic diversity in Namibia by introducing genetically diverse accessions from other countries and maintaining the diversity through breeding programs.