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Tylosema esculentumis a perennial legume that is predominant in Namibia, Botswana, and South Africa. It is rich in nutrients, drought-tolerant, and a climate change contender for future agriculture. The objectives of this study were to isolate and identify culturable bacterial endophytes. Our study assessed the mean CFUs/mL among the tuberous roots, stems, and leaves to determine the density and diversity using ANOVA. It was a quantitatively controlled experiment in which seeds were grown in a greenhouse. The bacteria number varied from 1.29 × 108to 3.5 × 108CFU/ml of broth, with the highest in the tuberous roots and the lowest in the leaves. At a 5% significant level, we revealed that there is a difference among the bacterial densities of the plant parts. Shannon-Weiner diversity showed that there is a higher diversity of bacteria in the tuberous roots. Of the isolates that were obtained, 53.8% belonged toEnterobacter, 15.4% toBacillus, 15.4% toPantoea, and 7.67% toBurkholderia. These discoveries have made us more aware of the endophytic bacteria we now have. These strains might thus be used in food crops to boost productivity, enabling food security, especially in Africa. The significance of the isolates in biological control, agriculture, and biotechnology for growth promotion will be determined by further research.

International scientific partnerships are key to the success of strategic investments in plant science research and the farm-level adoption of new varieties and technologies, as well as the coherence of agricultural policies across borders to address global challenges. Such partnerships result not only in a greater impact of published research enhancing the career development of early and later stage researchers, but they also ensure that advances in plant science and crop breeding technologies make a meaningful contribution to society by brokering acceptance of emerging solutions to the world problems. We discuss the evidence showing that despite a lack of funding, scientists in some African countries make a significant contribution to global science output. We consider the criteria for success in establishing long-term scientific partnerships between scientists in developing countries in Southern Africa (“the South”) and developed countries such as the UK (“the North”). We provide our own personal perspectives on the key attributes that lead to successful institutional collaborations and the establishment of sustainable networks of successful “North-South” scientific partnerships. In addition, we highlight some of the stumbling blocks which tend to hinder the sustainability of long-term “North-South” scientific networks. We use this personal knowledge and experiences to provide guidelines on how to establish and maintain successful long-term “North-South” scientific partnerships.

With the Climate change effects becoming more and more undoubted in the world populations, the reality of food production trends taking a negative curve is clear. This bring up the questions of whether the farmers will be able to produce food for the sustenance of the world population or not? The rate of developing food shortage coping mechanisms in this regard is slower that the ravaging negative climate change effects of drought and floods on farm performance. This commentary has the aim of requesting a fresh discussion around the fundamentals of what is food, what is a food security and what is nutritional security? It is possible that the humanity has a perception that needs refocusing. This is a perception that some people may choose out of non-food safety issues not to eat certain foods while other however healthily eat such food. It therefore becomes hard to technically accept that food is in short supply for those the opt not to eat that which is edible.

The genus Moringa is a phenotypically varied group of trees and shrubs, widely distributed in the tropical and subtropical regions, whose species are mostly sought after for nutritional, nutraceutical and industrial use. The Namibian Moringa ovalifolia consists of phenotypically different populations scattered across the country and occurring in different ecological systems. In the present study, species boundaries of the Moringa ovalifolia from Halali, Uis, Sesfontein, Sprokieswoud (Etosha) and Namib Nauflukt Park were assessed using internal transcribed spacer sequences of nuclear ribosomal DNA data. In order to reconstruct the phylogenetic relationships of the populations under investigation, Cylicomorpha parviflora Urb. was used as an out group to root the phylogenetic trees. Results from all the phylogenetic analysis methods used in this study, provided evidence for one monophyletic group for all the Namibian Moringa ovalifolia populations. All the three phylogenetic analysis methods inferred that the Namibian Moringa ovalifolia is a sister clade to other Moringa species. Furthermore, the Moringa ovalifolia from different Namibian populations nested together in all analyses forming a monophyletic clade, inferring a relatively recent separation from each other. The results demonstrate that the different populations of the Namibian Moringa ovalifolia are phylogenetically similar despite their morphological differences and geographic isolations.

Water is a global need for the health and survival of all life forms and a habitat to some. However, approximately one billion people in developing countries do not have access to safe drinking water in which Namibia is not an exception. Rural communities of Ohangwena and Omusati regions of Namibia construct hand-dug wells as a source of water. However, these hand-dug wells are not monitored for water quality and are generally poorly constructed. In addition, these hand-dug wells are easily accessed by both humans and animals making them a potential reservoir for zoonotic bacteria partly known to aid antimicrobial resistance development, a global health concern. A metagenomics analysis targeting the 16S rRNA gene was used to detect the bacterial communities in a total of 40 hand-dug well water samples, with 20 being from the wet season and the rest from the dry season. A total of 57 bacterial pathogens were detected with a diverse of zoonotic assemblage. Analysis revealed significant differences in diversity and evenness, and no significant difference in richness of zoonotic bacterial pathogens in hand-dug wells between the wet and dry seasons (P < 0.05) with the dry season having a higher diversity and evenness compared to the wet season. The analysis showed that the hand-dug well water was not definitely safe for human and livestock consumption and their exposure to zoonotic pathogens was pronounced in the dry season.

Namibia is a large country with a population slightly above 2 million of which 73% live in rural areas. It is the driest country in sub-Saharan Africa with unpredictable rainfall patterns which occur between October and May. The Cuvelai Etosha Basin is a rural setting in which most people depend on groundwater to circumvent water scarcity by the construction of hand-dug wells. Communities consume hand-dug well water throughout the year without; knowledge of its safety, and treatment prior to use. Hence, this study aimed at evaluating the seasonal safety and quality of hand-dug well water for human consumption. A 16S rRNA metagenomics study was conducted to explore the influence of season on the human pathogenic bacterial species richness, diversity, evenness and abundance in the hand-dug wells. Bacterial pathogens were identified and analysis revealed no significant difference in species richness and diversity, and a significant difference in species evenness and abundance between the wet and dry seasons. Hence, seasonality had an influence on human bacterial pathogens evenness and abundance but had no influence on species richness and diversity. In addition, the water in hand-dug wells of the Cuvelai Etosha Basin is not safe for consumption and domestic use unless sanitized. It is recommended that efforts should be made to treat the water prior to use, and hand-dug wells should be properly constructed to reduce contamination.

To determine the prevalence of pathogenic bacteria in street vended ready-to-eat meats in Windhoek, Namibia, a total of 96 street vended ready to eat meat samples were evaluated. Prevalences of 42%, 52%, 15%, 6% and 83% were observed for Escherichia coli, Staphylococcus aureus, Listeria monocytogenes, Shigella and Enterobacteriaceae respectively, while the highest aerobic plate counts were 7.74 Log10 cfu/g, 5.67 Log10 cfu/g, 5.12 Log10 cfu/g, 4.56 Log10 cfu/g, 3.3 Log10 cfu/g, 5.75 Log10 cfu/g respectively. Unsatisfactory microbial levels were 32% for aerobic plate count, 26% for Enterobacteriaceae, 35% for Escherichia coli, 11% for Listeria monocytogenes, 7% for Staphylococcus aureus and 6% for Shigella. Salmonella was detected in 11% and 40% of samples from two suburbs. The unsatisfactory microbiological quality of some ready-to-eat meats necessitates the provision of training on food safety and hygiene to street vendors for consumer protection.

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.

For many years, the generation of nitrates from organic sources in order to create nutrient solutions for hydroponics had proved a challenge until lately when microorganisms were introduced to perform this task. The objectives of the current study therefore were to use local microbial consortium to nitrify goat manure in water and to determine microbial diversity in the inoculated consortium. Therefore, microorganisms were sourced from garden soil and natural compost at the Sam Nujoma Marine resources Research Centre (SANUMARC) in Henties Bay Namibia to convert organic nitrogen in goat manure from Utuseb farm near Walvis Bay into nitrates. Results show that microbial consortium from the compost source produced significantly (P< 0.05) more nitrates followed by the garden-soil source, suggesting that it is necessary to add inoculum in order to generate nitrate from goat manure. The ammonia oxidising bacteria (AOB) community from the compost sample’s was dominated by uncultured ammonia-oxidising species followed by uncultured bacterium (both not identified), with the least being Nitrosomonas species. The AOB community from the garden source was dominated by uncultured bacterium, followed by uncultured ammonia-oxidising species and the least being Nitrosomonas species. NOB community from the compost source was dominated by uncultured bacterium, followed by Nitrobacter winogradskyi and Nitobacter vulgaris with the least being Nitrococcus mobilis and Nitrospira moscovensis. For the garden soil microbial source, uncultured nitrite-oxidising bacteria dominated followed by uncultured bacterium, whereas the least species were N. moscovensis and Nitrobacter alkalicus. Moreover, community composition of the compost sample was more diverse than the community from the garden sample. These results maintain that there are other unculturable yet important microbes doing the same job if not better than the known ones, in this case suggesting that there may be other local nitrite-oxidizing bacteria responsible for oxidizing ammonia other than the traditionally known Nitrobacter, Nitrospira and Nitrococcus species. Key words: Organic hydroponics, ammonification, nitrification, ammonia-oxidizing bacteria, nitrite-oxidizing bacteria.

The Cuvelai Etosha Basin of Namibia is characterised by complex aquifer systems with multi-layered aquifers and various water qualities. Some parts of the basin have been covered with a pipeline system that supplies purified surface water from the Kunene River. Locations that lack a pipeline system utilise hand-dug wells as a source of drinking water. These wells draw water from shallow perched aquifers and are not protected from surface contamination nor is the water quality monitored. Sanitised water supply is relevant for the growth and development of societies and is a priority of the United Nations Millennium Development Goals. A bacteriological water quality study aimed at investigating the presence and seasonal variation of; Citrobacter, Escherichia, Klebsiella, Enterobacter, Proteus, Salmonella, Shigella, and Pseudomonas species was conducted on 44 hand-dug wells in the Ohangwena and Omusati regions of the Cuvelai Etosha Basin. Samples were collected from both the wet and dry seasons. Results disclosed the presence of Salmonella, Shigella, Citrobacter, Escherichia, Klebsiella, Enterobacter, Proteus, and Pseudomonas species. Chi-square confirmed a significant seasonal variation in Salmonella (P 0.05), Escherichia (P > 0.05), Klebsiella (P > 0.05), Enterobacter (P > 0.05), Proteus (P > 0.05) and Pseudomonas (P > 0.05) species. Water from these hand-dug wells is not safe for drinking unless it is subjected to appropriate treatment. It is recommended that hand-dug wells should be properly constructed at safe distances from contaminating structures such a pit latrines and routinely assessed for pathogens, and the water should be sanitized prior to consumption.

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.

Vachellia tortilis is a tree belonging to the family Fabaceae that inhabits high temperature and dry environments of the world. It is ecologically and economically significant amongst others of the genera Vachellia and Senegalia. It is native to Namibia and several other countries. Various parts of the V. tortilis plant are used for different therapeutic purposes both in the traditional and pharmacological settings. However, V. tortilis is vulnerable to pathogenic infection to which they lack natural resistance and little is known regarding the pathogens responsible for such infections. The aim of the study was to isolate and identify the fungal species associated with twig dieback disease in V. tortilis. Pure cultures from diseased V. tortilis were grown using potato dextrose agar (PDA) and DNA was subsequently isolated and later amplified in a PCR reaction using ITS1 and ITS4 primers. Sequencing and BLAST search revealed the identity of the isolates as; Penicillium rubefaciens, Penicillium herbarum, Trichoderma longibrachiatum and Trichoderma harzianum. Results indicated that P. herbarum was associated with disease symptoms in A. tortilis, T. longibrachiatum and T. harzianum were antagonistic fungi while the effect of P. rubefaciens on V. tortilis remained unknown. It is recommended that further investigations using Koch’s postulates should be performed on V. tortilis using the isolates.

Detection of phytopathogens that are involved in causing disease symptoms in plants and crops is of prime importance as a key step in disease treatment and management. Ziziphus mucronata is a species endemic in temperate and tropical climates and used traditionally in the treatment of infectious diseases. The common bean (Phaseolus vulgaris) is a rich source of nutrients for the human diet. Just like most crops, it is not immune to fungal diseases and reports had been received of P. vulgaris showing signs on disease. The aim of this study was to isolate and characterize the fungal species associated with the disease symptoms in the Z. mucronata and P. vulgaris. Fungal species where isolated from surface-sterilised symptomatic bark of Z. muconata and fresh green bean pods. These where grown on petri dishes containing Potato Dextrose Agar and incubated at room temperature. Pure cultures where then obtained by transferring small segments of fungal growth to a new petri dish that contained PDA. During DNA extraction the pure cultures where first homogenized using liquid nitrogen and then the rest of the extraction carried out as stipulated in the Zymo extraction kit. The Nanodrop was used for quantifying the DNA and amplification of the conserved Internal Transcribed Spacer (ITS) region of Ribosomal RNA genes was carried out using ITS1 and ITS2. The PCR products were sequenced at Inqaba Biotech Industries in South Africa. The obtained sequences were then compared by alignment with known sequences in the Genbank using Basic Local Alignment Search Tool (BLAST). The BLAST searches were able to reveal the fungi isolated from the Z. mucronata as Fusarium penzigii and Fusarium dimerum while the fungi isolated from P. vulgaris shown to be Phoma destructiva, with 100 %, 95% and 100% sequence similarity respectively. The next step in this work is carry out Koch‘s postulates to determine which of this fungi is the causal agent of the observed diseases symptoms in order to start a targeted diseases management programme.

Advances have been recently made in the breeding and characterization of three major legume crops of the semiarid tropics, chickpea, pigeon pea, and groundnut. However, other wild‐growing legumes, called “orphan legumes,” with potential as crops, but are not yet cultivated would benefit from further attention. This review considers the domestication of one such plant, marama bean (Tylosema esculentum). Marama has long been recognized as a potential crop particularly for southern Africa, but coordinated, long‐term research and development has been lacking. Marama is a perennial, outcrossing hexaploid, growing under extreme conditions in a restricted geographic range; only natural stands exist that are likely to be overexploited. Marama has two potential units of economic yield, seed and tuber. The seed is protein‐ and oil‐rich, with potential in the pharmaceutical and cosmetic industries while the tuber is high in carbohydrates. In this review, the different aspects of bringing a wild plant into cultivation are considered, together with the additional socioeconomic benefits of developing a breeding program. An international collaboration is analyzing aspects of the plant structure and physiology, molecular biology, and its interactions with environment with a view to developing marama as a crop, with a role in food security, that could be harvested by local communities. Molecular topics considered include next‐generation sequencing for developing molecular maps, genotyping by sequencing, identification of quantitative trait loci for important agronomic traits, protein quality, and incompatibility mechanisms. To achieve domestication requires seed gardens and fields, and the phenotyping of marama material from different locations. Community engagement will also ensure agronomic sustainability and farmer participation. This review describes an approach for a successful outcome of a breeding program to introduce improved marama and highlights the challenges in achieving this, which is a paradigm for the difficulties in the cultivation of “orphan species.”

Agriculture is one of the most important sectors in the world. It provides food for the growing world populations while also creating employment opportunities. This sector, however, is greatly threatened by climate change, increased water scarcity, droughts, land degradation and poor management of resources. The state of drylands in the world raises great concern given that it largely affects third world countries particularly subsistence farmers. This raises questions with regards to the extent of drylands and the progression of land degradation and water availability. This article presents current efforts to track development of land degradation and developing systems that improve agricultural productivity in drylands. Our review finds that given the climatic and environmental threats to agricultural productivity suitable solutions such as improved research and resource management can lead to increased production for food security and even commercialization. Therefore, it is imperative to allow access to advanced technology to subsistence farmers.

Malnutrition is a medical condition caused by an unbalanced diet, typically characterised by stunting and wasting in children. Malnutrition causes approximately a third of all deaths in children between 0-59 months mostly in developing countries. In Namibia, 24% of children under the age of 5 years are stunted while 6.2% are wasted. Tylosema esculentum, commonly known as marama bean is an underutilised legume of high nutritious value. Indigenous to Namibia, marama bean seeds have comparably high protein and lipid content. Marama bean is an appealing crop to Namibia in particular due to its low cultivation demands as it grows in sandy soils with minimal water requirements and no need for fertilisers. Ten accessions of marama bean seeds were analysed for their nutritional composition. The results indicate that ash content was found ranging between 2.13% and 3.46%. Minerals analysed were calcium, iron, magnesium, phosphorus and zinc. Their range of concentrations were 750.1-2306.2 mgkg-1, 53.9-322.4 mgkg-1, 1764.1-7415.0 mgkg-1, 4300.8-5267.9 mgkg-1 and 32.2-48.8 mgkg-1 respectively with no significant difference in concentration among the ten accessions. Correlation analysis of the minerals within the accessions showed that the correlations between zinc-magnesium and zinc-phosphorus concentrations were significantly different as compared to the rest of the pairs for all accessions. When analysed, the maximum and minimum amounts of crude fat and carbohydrates were 29.9%-44.1% and 19.4%-39.0% respectively which were found to not have a significant difference. However, the protein analysis determined that there was a significant difference with PMBC2 (mean content 34.6%) being the most significant accession. Therefore, PMBC2 was found to be the most suitable accession for crop development and domestication. This study’s main contribution with respect to the domestication of marama bean was the identification of the most superior accession based on nutritional composition.

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.

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.

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

During the past few years, disease symptoms in many Acacia trees in the Windhoek Mu‐ nicipality area and the rest of Namibia have been observed. This observation triggered the investigation of phytopathological aspects that are reported in this chapter. The im‐ portance of indigenous trees of the Namibia flora is apparent considering that Namibia has two old deserts within its borders: the Namib Desert and the Kalahari Desert. Nam‐ bia’s tourism and meat industry are dependent on the indigenous trees of Nambia flora. The trees are the primary source of vegetation land cover (attracting tourists), and they provide browsing food matter to domestic livestock and wild animals (sources of meat). Hence, it is important to ensure that a healthy vegetation is maintained in this area.. This survey is the first dedicated step to find ways of protecting them from disease-causing agents. The aim of this survey is to investigate the possible causes of disease symptoms in trees. It is important to understand the biology of the pathogenic agents to propose a pos‐ sible method to control the diseases. The survey involved sampling leaves, stems and roots from dying trees that show symptoms such as branch girdling, gum oozing and de‐ foliation, suspicious general twig wilting and die-back. The survey was carried out in pla‐ ces where symptoms were observed. The tree surveys were done on Aloe zebrina, Tylosema esculentum, Syzygium and Acacia species. Primary isolations from plant material and then single-spore pure cultures were made for identification. In this chapter, we re‐ port isolation and identification of Microsphearopsis sp., Dreschelra sp., Botryosphearia spp., Acremonium spp., Coniothyrium sp., Phellinus spp., Cytospora sp., Fusarium sp., Scytalidium sp., Phoma spp., Gliomastix sp., Trichoderma koningii, Peacilomyces variotii, Alternaria citri and Curvularia palescens from the diseased trees. This work is still ongoing. This study paves way for proper designing of control methods to protect crops, trees and their biodi‐ versity. The protection of plant biodiversity ensures better reaping of food products and other ecosystem services and products. Without knowledge of the identity of these dis‐ ease-causing agents, it is not possible to accurately identify and manage threats to food production and threats to the native botanical biodiversity of Namibia.

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.

Effects of mine dump pollution on semiarid savanna vegetation were investigated in Kombat, Namibia. Vegetation structure, species richness, composition and diversity were compared between polluted and control sites. Concentrations of arsenic, chromium, copper, lead and zinc in soils were significantly higher closer to a 99-year-old mine dump than in a control site and exceeded internationally recommended guidelines by as high as 11 times. Mine dump pollution has significantly reduced woody plant densities, species richness and diversity in the affected area due to disappearance of pollution-sensitive species and preponderance of tolerant ones. Species composition and structure of vegetation close to the mine dump significantly changed, possibly due to negative impacts of heavy metals on recruitment as pollution-sensitive species died off, whereas tolerant species invaded the vacated ecological niches. Ordination analyses confirmed a strong pollution gradient, with measured heavy metals accounting for 57.3...

Seven strains of symbiotic bacteria from root nodules of local races of Bambara groundnut (Vigna subterranea) and peanuts (Arachis hypogaea) grown on subsistence farmers' fields in the Kavango region, Namibia, were previously characterized and identified as a novel group within the genus Bradyrhizobium. To corroborate their taxonomic status, these strains were further characterized using a polyphasic approach. All strains possessed identical 16S rRNA gene sequences with Bradyrhizobium yuanmingense CCBAU 10071T being the most closely related type strain in the 16S rRNA gene phylogenetic analysis, and Bradyrhizobium daqingense CCBAU 15774T in the ITS sequence analysis. Phylogenetic analysis of concatenated glnII-recA-rpoB-dnaK placed the strains in a highly supported lineage distinct from named species of the genus Bradyrhizobium, most closely related to Bradyrhizobium yuanmingense CCBAU 10071T. The species status was validated by results of DNA–DNA hybridization. Phylogenetic analysis of nifH genes placed the novel strains in a group with nifH of ‘Bradyrhizobium arachidis’ CCBAU 051107 that also nodulates peanuts. The combination of phenotypic characteristics from several tests including carbon source utilization and antibiotic resistance could be used to differentiate representative strains from recognized species of the genus Bradyrhizobium. Novel strain 58 2-1T induced effective nodules on V. subterranea, Vigna unguiculata and A. hypogaea, and some strains on Lablab purpureus. Based on the data presented, we conclude that our strains represent a novel species for which the name Bradyrhizobium subterraneum sp. nov. is proposed, with 58 2-1T [ = DSM 100298T = LMG 28792T = NTCCM0016T (Windhoek)] as the type strain. The DNA G+C content of strain 58 2-1T was 64.7 mol% (T m).

The Kombat tailings dam, surrounded by agricultural lands, has been exposed to water and wind erosion over a long period of time. The objectives of this research were: (1) to characterize the tailings and the surrounding agricultural soils with respect to the mineral and trace element composition; (2) to determine the degree of soil pollution using soil contamination indicators; (3) to assess the environmental risk of polluted agricultural soil; and (4) to identify dominant type (mechanical and/or chemical) and dominant agent (water and/or wind) of metal dispersion from the tailings. A sequential extraction procedure was used to determine binding mechanisms involved in the retention of metals in tailings and soils under the influence of tailings, which indicate the trace metals bioavailability, the threat to groundwater pollution, as well as the dominant type of dispersion. Among seven analysed elements, copper and lead showed significantly high concentrations in tailings, especially in dry season (up to 9086 mg/kg and 5589 mg/kg, respectively). As a consequence, adjacent arable soils have high concentrations of Cu and Pb (up to 150 mg/kg and 164 mg/kg, respectively). Enrichment factors for lead and copper reveal severe contamination, while geoaccumulation indices disclose moderate to strong contamination by both elements. The combined pollution index points out high contamination. The main binding phase for Cu and Pb is the reducible fraction (oxides, hydroxides, oxyhydroxides). Similar metal distributions in the sequential extraction fractions of tailings and soils support the assumption that wind and water disperse tailings predominantly by mechanical transport to the surrounding agricultural soil. Although agricultural soils are contaminated with Pb and Cu, these metals are relatively strongly bound to the soils and are of medium risk for their mobilisation after The Risk Assessment Code (up to 20% for Cu and up to 36% for Pb). Though rehabilitation of tailings dam, as well as limitation of certain crop use on polluted agricultural land, is recommended.

Plants produce polygalacturonase-inhibiting proteins (PGIPs) as part of their defense against disease. PGIPs have leucine-rich motifs, a characteristic shared by many proteins involved in plant resistance against pathogens. The objective of this study was to clone and analyse the partial sequences of the pgip genes from five selected commercially important Eucalyptus species. Genomic DNA from E. grandis, E. urophylla, E. camaldulensis, E. nitens and E. saligna was isolated from young leaves and used as the template in PCR reactions. Primers PC1, previously described, and Per3, developed in this study, were used in a degenerate PCR reaction to amplify a pgip fragment. A PCR fragment of 909 bp was amplified from each Eucalyptus spp., cloned and sequenced. The Eucalyptus pgip genes were highly conserved (98–100% identity). Analysis of the deduced amino-acid sequences revealed high similarities (44–94%) with other known PGIPs. In general, PGIPs have high homologies within genera as is the case in the genus Citrus. These observations strengthen the belief that PGIP plays an important role in plants.

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 occurrence of Salmonella is a global challenge in the public health and food production sectors. Our study investigated the prevalence, serovar and antimicrobial susceptibility of strains of Salmonella serovars isolated from animal feed (meat-and-bone and blood meal) samples from two commercial abattoirs in Namibia. A total of 650 samples (n=650) were examined for the presence of Salmonella. Results showed that 10.9% (n=71) were positive for Salmonella. Of the Salmonella serovars isolated, S. Chester was the most commonly isolated serovar (19.7%), followed by S. Schwarzengrund at 12.7%. From the Salmonella isolates, 19.7% (n=14) were resistant to one or more of the antimicrobials (nalidixic acid, trimethoprim-sulfamethoxazole, sulfisoxazole, streptomycin and/or tetracycline), whereas 80.3% (n=57) were susceptible to all 16 antimicrobials tested. Resistance to sulfisoxazole and the trimethroprimsuflamethoxazole combination were the most common. The resistant isolates belonged to ten different Salmonella serovars. The susceptibility of most of the Salmonella isolated to the antimicrobials tested indicates that anti-microbial resistance is not as common and extensive in Namibia as has been reported in many other countries. It also appears that there is a range of antimicrobials available that are effective in managing Salmonella infections in Namibia. However, there is some evidence that resistance is developing and this will need further monitoring to ensure it does not become a problem.

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.

The morama bean is an underutilized leguminous oilseed native to the Kalahari Desert and neighboring sandy regions of Botswana, Namibia, and South Africa (Limpopo, North-West, Gauteng, and Northern Cape provinces), and forms part of the diet of the indigenous population in these countries. It is also known as gemsbok bean, moramaboontjie, elandboontjie, braaiboonjie, marama, marumana, tsi, tsin, gami, and ombanui. It is reported as an excellent source of good quality protein (29–39%); its oil (24–48%) is rich in mono- and di-unsaturated fatty acids and contains no cholesterol. Morama is a good source of micronutrients such as calcium, iron, zinc, phosphate, magnesium, and B vitamins including folate. It is also reported to be a potential source of phytonutrients including phenolic compounds (e.g., tannins), trypsin inhibitors, phytates, and oligosaccharides, components which have been shown in other foods to contribute to health in particular, prevention of noncommunicable diseases such as cardiovascular diseases, diabetes, and some cancers. From a nutritional and health perspective, the morama bean has potential commercial value as a cash crop and value-added products, particularly in the communities where it is found.

Cryphonectria cubensis causes a serious Eucalyptus canker disease. Fungal cell wall degrading enzymes (CWDEs) are important during the early stages of interaction of the fungus with Eucalyptus. To improve our understanding of the molecular regulation of the interaction of Eucalyptus and C. cubensis, the relevant genes involved in this interaction should be identified, cloned and studied. The aim of this study was, therefore, to clone the endopolygalacturonase (endoPG) gene of C. cubensis. C. cubensis was grown on a medium supplemented with Eucalyptus cell wall extracts. Degenerate primers were designed to amplify part of the endoPG gene from C. cubensis genomic DNA. The resulting sequence was used to design specific primers for use in inverse PCR to amplify the entire endoPG gene of C. cubensis (ccen-1). The endoPG sequence of C. cubensis has 93% amino acid sequence similarity to that of the chestnut blight pathogen, Cryphonectria parasitica.