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With the ever-increasing pace of urban life, many people now rely a lot on processed foods. Some of these processed foods are prepared hygienically and yet some are prepared in homestead and brought to the open market, without having gone through any microbial quality checks. This has in the recent past led to outbreaks of food -borne diseases such as Cholera and Salmonellosis to mention a few. In this study, processed food samples were collected from three open markets in Windhoek namely Single quarters, Soweto market and the Okuryangava Bus stop. The samples included maize (flour), dried Cleome gynandra leaves, mopane worms, roasted groundnuts, minnos, and cooked beef steaks. Morphological identification was done based on the macroscopic characters based on the colour, shape, and texture and microscopic characterization using lactophenol cotton blue wet mount. DNA was extracted from the fungal isolates and PCR was performed using ITS1 and ITS4 primers. The PCR products were sequenced, and the results were used for identification using the BLAST search program in NCBI. Dried Cleome gynandra contained most of the isolated fungal species which were identified Pichia burtonii, P. macrostoma, Dothidealus, and A. parasiticus. However, Aspergillus species were present in all the food samples and A. parasiticus was found in all food samples except the ground nuts. These could be an indication of that the fungus prefers low water activity and possibly high salt concentrations to survive.

The influence of organic hydroponic nutrient solution on tomato growth and yield was studied using a randomized complete block design (RCBD) with three treatments (organic nutrient solution, conventional hydroponic fertiliser (as positive control) and plain tap water (as negative control)) replicated three times. Determinate tomato seeds were germinated and transplanted into the 3 treatments. Twenty days after transplanting, vegetative response variables were recorded at fifteen days intervals from each treatment. Vegetative response variables included plant height, number of leaves and stem diameter. The reproductive parameters included number of flowers per plant, number of fruits per plant, average fruit weight (g), yield (kg) per plant and yield (kg) per treatment. Furthermore, the organic nutrient solution formulated from goat manure positively improved plant growth and yield performance of a tomato crop, and provided a technique feasible and alternative to conventional hydroponics. These results open further possibilities for other crops currently grown in hydroponics using conventional fertilisers. Key words: Organic nutrient solution, growth, yield, goat manure, tomato.

Legumes have been used as food by indigenous people of Africa yet their full potential as food sources has not been completely realized. With modern technologies such as marker-assisted selection and mutational breeding, there is scope for rapid improvement of germplasm in these underutilized species. One approach is to induce genetic mutations through irradiation of plant tissues with neutrons or gamma rays generating molecular changes. The irradiation leaves residual radiation in the exposed tissues creating offspring with new features. Genetic mutations in plants can improve their performance, germination, quality, size and disease resistance. The effects of radiation applied to marama bean (Tylosema esculentum) were explored. The aim of this study was to screen individuals of T. esculentum derived from seeds irradiated with gammarays using microsatellite markers. There were two irradiation treatments -50 and 100 gamma ray irradiations that were compared to non-irradiated seeds as controls. For each treatment, seeds were imbibed and germinated. Seed emergence rates and percentages were ascertained. Each set of seeds was genotyped using a SSR marker - MARA039, located in a sub-unit of a polygalacturonase – an enzyme that mainly regulates seed germination. In regard to emergence, significant differences between the irradiated seeds and non-irradiated counterparts were noted. Irradiated seeds germinated faster and in adosage-dependent manner compared to non-irradiated counterparts (p>0.05). Genotyping revealed that the total number of AGA repeats in the microsatellite region shifted from its original five in the controls to between four and seven in the irradiated seeds. Furthermore, there were several point mutations in the irradiated seeds as compared to the controls. The study findings, suggest that irradiation may induce beneficial mutational changes such as faster germination rate of the marama bean, considering that the mutated microsatellite repeat region is located in gene encoding the enzyme regulating seed germination in plants. Key words: Marama bean, Tylosema esculentum, mutational breeding, irradiation, seed cycle, SSR.

Tylosema esculentum (marama bean) is one of the underutilized legumes that have potential to provide protein and fatty acids to ensure food security in dry parts of Southern Africa. In order to establish rapid domestication programs for the plant, it is important to explore the plant’s genome and identify functional genes molecular markers like microsatellites in order to develop molecular tools. With the advent of high-throughput sequencing technologies and associated bioinformatics methods, expressed sequence tags (ESTs) have been developed for many plant species. These are being developed as an economic means of obtaining large numbers of gene sequences. The aim of this study was to identify genes with important roles for valuable agronomic traits and microsatellite sequences for marama bean. The authors reported the identification of genes associated with embryonic development and microsatellite sequences. The future direction will entail characterization of these genes using gene over-expression and mutant assays. Key words: Namibia, simple sequence repeats (SSR), data mining, homology searches, bioinformatics, Tylosema esculentum.

A diverse group of soil bacteria known as plant growth promoting rhizobacteria (PGPR) is able to inhabit the area close to plant roots and exert beneficial effects on plant growth. Beneficial interactions between rhizospheric bacteria and plants provide prospects for isolating culturable PGPR that can be used as bio-fertilizers for sustainable crop production in communities that cannot easily afford chemical fertilizers. This study was conducted with the aim of isolating rhizospheric bacteria from grasses along the Kavango River and screening the bacterial isolates for plant growth promoting characteristics. The bacteria were isolated from rhizospheres of Phragmites australis, Sporobolus sp., Vetiveria nigritana, Pennisetum glaucum and Sorghum bicolor. The isolates were screened for inorganic phosphate solubilization, siderophore production and indole-3-acetic acid (IAA) production. The nitrogen-fixing capability of the bacteria was determined by screening for the presence of the nifH gene. Up to 21 isolates were obtained from P. australis, Sporobolus sp., S. bicolor, P. glaucum and V. nigritana. The genera Bacillus, Enterobacter, Kocuria, Pseudomonas and Stenotrophomonas, identified via 16S rDNA were represented in the 13 PGPR strains isolated. The isolates exhibited more than one plant growth promoting trait and they were profiled as follows: three phosphate solubilizers, four siderophore producers, eight IAA producing isolates and five nitrogen-fixers. These bacteria can be used to develop bio-fertilizer inoculants for improved soil fertility management and sustainable production of local cereals.

Sorghum is an important cereal that is processed into a variety of foods and leisure beverages across the African continent. Low sorghum yields experienced in agriculture is a result of major production constraints such as soil nutrient deficiency and plant disease. It is important that the methods for crop production are of a sustainable nature as the chemical fertilizers in current use are detrimental to the natural environment. The aim of this study was to determine the effects of plant growth promoting (PGP) bacteria on growth of Sorghum bicolor. PGP bacteria isolated from the rhizosphere of Pennisetum glaucum (Pseudomonas stutzeri ACM2-32, Kosakonia cloacae FCM2-50, Bacillus subtilis ASM1-59 and Bacillus amyloliquefaciens LSM1-61) and S. bicolor (Stenotrophomonas maltophilia LCS2-11) plants in Kavango (Namibia), were used as peat-based inoculants to evaluate their effects on the growth of S. bicolor. The combination treatment T9 (B. amyloliquefaciens LSM1-61: K. cloacae FCM2-50: P. stutzeri ACM2-32) significantly (p = 0.032) enhanced the biomass of S. bicolor as compared to the water control. Single inoculants consisting of S. maltophilia LCS2-11, K. cloacae FCM2-50 and B. amyloliquefaciens LSM1-61 and combination inoculants T7, T8 and T9, enhanced S. bicolor root biomass as much as a commercial fertilizer control. These results indicate that the plant growth promoting bacteria induced a beneficial effect on growth of sorghum seedlings. The future work involves testing these promising inoculants on growth of these sorghum plants to maturity stage to determine effects on seed yield over three seasons in multi-location trials. Key words: Rhizosphere bacteria, peat based inoculants, plant growth promoting bacteria, Sorghum bicolor.

The Kavango region (Northern part of Namibia) were the study was carried out, is extensively involved in agriculture and is also known to be dominated by the sandy aerosols soils. The bad soils in the region, which have poor nutrients and water holding capacity, combined with a fast rate of climate change in the region has contributed in the reduction in yield of most crops grown in the area. The main aim of the study was to determine cowpeas response to bio-inoculants by assessing yield of the pulse. Six different cultivars of Vigna unguiculata (Cow pea) were evaluated for their response to bio-inoculants. These cultivars were subjected to 3 different treatments. One with chemical fertilizer, another with Bradyrhizobium strains (14-3) and (1-7) bio-inoculants and a third which was a negative control with no treatment. After 90 days post seeding the cultivars were harvested and different yield parameters assessed. The cowpeas that were subjected to the bio-inoculant treatments yielded a later grain yield in kg per hectare as compared to the negative control and the fertilizer treatments. The outcome of this study therefore provided the local subsistence farmers with a cheaper eco-friendly alternative to mineral fertilizers.

During one of our greenhouse experiments on the marama bean plant (Tylosema esculentum) at the University of Namibia, various signs of necrosis and spotting were observed on leaf tissues of the newly developed seedlings. In this study, we hereby describe findings of the investigations undertaken to attempt and determine the possible causative agent(s) of such plant leaf infections. In brief, infected seedling leaves were first surface-sterilized and then used in form of leaf-discs (2 x 2 mm), to inoculate potato dextrose agar (PDA). Alongside this, control leaves were also similarly treated and overlaid onto PDA. While fungal growths were observed on all infected leaf-discs, no growth was observed on control discs. For each of the various fungal strains growing on the infected leaf discs, pure cultures were obtained by repeatedly sub-culturing the strains onto PDA. Subsequently, single spore cultures were also aseptically isolated from each of the obtained pure cultures and further developed into mycelia through inoculation and incubation in potato dextrose broth (PDB). All in all, a total of eight single spore cultures were obtained from the overall inoculations and sub-culturing. Subsequently, the total genomic DNAs of each of the obtained single spore cultures were isolated followed by amplification of their internal transcribed spacer (ITS) regions. The amplified ITS regions were then sequenced followed by a comparison of their nucleotide patterns with the GeneBank. Such a comparison then revealed the presence of a complex of several fungal isolates with eight commonly known species: Penicillium brevicompactum, Epicoccum sorghi, Rhizopus stolonifer, Alternari solani, Fusarium equiseti, Penicillium olsonii, Fusarium chlamydosporum and Fusarium incarnatum. These fungal species are commonly known to cause various diseases and infections in legumes and other agronomically important crops. Ideally, the presence of these fungal species in marama bean and their involvement in leaf tissue decay should be noted with great concern and interest since this plant has recently been proposed as a potential leguminous crop for possible adoption and utilization in domestication efforts. Key words: Marama bean, Tylosema esculentum, fungi, Namibia, leaf infection, internal transcribed spacer (ITS).

Aim: The purpose of this research was to determine the prevalence of Salmonella in raw beef produced from selected commercial abbatoirs in Namibia. Methodology: A total of 9508 of beef samples from three different types of samples; meat cuts, carcass swabs and meat fluid were collected from the three local abattoirs over a period of two years starting from January 2008 to December 2009. Pre - enrichment for isolati on of Salmonella was done in Buffered peptone water followed by enrichment in the Rappaport - Vassiliadis and selenite cystine broth. The isolation of Salmonella was done on Xylose Lysine Desoxycholate and Brilliant Green agar followed by biochemical confirm ation and serotyping according to Kauffman White scheme. Results: The overall prevalence of Salmonella was 0.85 % for beef samples derived from meat cuts, meat fluid and carcass swabs. The prevalence of Salmonella in carcass swabs (2.67 %) was significantly different ( P = 0.0 5) from that of meat cuts (0.50 % ) and meat fluid (0.43 %). No significant difference ( P = 0.05) on the prevalence of Salmonella existed between the meat cuts and meat fluid. A total of 34 different types of Salmonella serovars were identified with S. Chester being the most frequently isolated serovars (n = 12), followed by S. Reading and S . Bredeney (n = 6) and S. Typhimurium (n = 5). Conclusions: The prevalence of Salmonella in raw beef found in this survey was lower than those observed in Sub Sahara Africa with S. Chester being the most prevalent serovar. Original Research Article

CurrentPennisetum glaucum(L.) R. BR. cultivars in Namibia have overall poor performance posing a threat to the nation’s food security because this crop is staple for over 70% of the Namibian population. The crop suffers from undesirable production traits such as susceptibility to diseases, low yield, and prolonged reproductive cycle. This study aimed to understand the genetic diversity of the crop in Namibia by simple sequence repeats (SSRs) and morphology analysis. A total of 1441 genotypes were collected from the National Gene Bank representing all the Namibian landraces. A sample of 96 genotypes was further analyzed by SSR using Shannon-Wiener diversity index and revealed a value of 0.45 indicating low genetic diversity. Ordination using Principal Coordinate Analysis (PCoA) on SSR data confirmed clusters generated by UPGMA for the 96P. glaucumaccessions. UPGMA phenograms of 29 morphological characterized genotypes were generated for SSR and morphology data and the two trees revealed 78% resemblance. Lodging susceptibility, tillering attitude, spike density, fodder yield potential, early vigour, and spike shape were the phenotypic characters upon which some clusters were based in both datasets. It is recommended that efforts should be made to widen the current gene pool in Namibia.

Marama bean (Tylosema esculentum) is an indigenous non-nodulating legume to the arid agro-ecological parts of Southern Africa. It is a staple food for the Khoisan and Bantu people from these areas. It is intriguing how it is able to synthesize the high-protein content in the seeds since its natural habitat is nitrogen deficient. The aim of the study was to determine the presence of seed transmittable bacterial endophytes that may have growth promoting effects, which may be particularly important for the harsh conditions. Marama bean seeds were surface sterilized and gnotobiotically grown to 2 weeks old seedlings. From surface-sterilized shoots and roots, 123 distinct bacterial isolates were cultured using three media, and identified by BOX-PCR fingerprinting and sequence analyses of the 16S rRNA and nifH genes. Phylogenetic analyses of 73 putative endophytes assigned them to bacterial species from 14 genera including Proteobacteria (Rhizobium, Massilia, Kosakonia, Pseudorhodoferax, Caulobacter, Pantoea, Sphingomonas, Burkholderia, Methylobacterium), Firmicutes (Bacillus), Actinobacteria (Curtobacterium, Microbacterium) and Bacteroidetes (Mucilaginibacter, Chitinophaga). Screening for plant growth-promoting activities revealed that the isolates showed production of IAA, ACC deaminase, siderophores, endoglucanase, protease, AHLs and capacities to solubilize phosphate and fix nitrogen. This is the first report that marama bean seeds may harbor endophytes that can be cultivated from seedlings; in this community of bacteria, physiological characteristics that are potentially plant growth promoting are widespread.

The fungus Fusarium circinatum causes pitch canker disease on mature pine trees and root rot and damping-off of pine seedlings. Endopolygalacturonases (endoPGs) play a major role during penetration of plants by fungi. Digestion of the pectic polysaccharides in the plant primary cell walls is one of the earliest functions of endoPGs during infection. The research objective was to clone and characterize the gene encoding endopolygalacturonase in F. circinatum. A 970-bp DNA fragment was cloned by using degenerate PCR amplification from F. circinatum DNA. Sequence data for this fragment were used to design specific primers for use in genome walking to amplify and sequence the remaining portion of the F. circinatum endoPG gene (Fcpg). The amino acid sequence predicted from this gene showed 90% and 87% similarity to Fusarium oxysporum and Fusarium moniliforme endoPGs, respectively.