Factors facilitating sustainable scientific partnerships between developed and developing countries.

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.

Genetic Diversity of Namibian Pennisetum glaucum (L.) R. BR. (Pearl Millet) Landraces Analyzed by SSR and Morphological Markers.

Current Pennisetum 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 96 P. glaucum accessions. 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.

Bradyrhizobium subterraneum sp. nov., a symbiotic nitrogen-fixing bacterium from root nodules of groundnuts.

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 DNA­DNA 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).

Molecular Detection and Characterization of Rickettsia Species in Ixodid Ticks from Selected Regions of Namibia.

Rickettsial pathogens are among the emerging and re-emerging vector-borne zoonoses of public health importance. Reports indicate human exposure to Rickettsial pathogens in Namibia through serological surveys, but there is a lack of data on infection rates in tick vectors, hindering the assessment of the relative risk to humans. Our study sought to screen Ixodid ticks collected from livestock for the presence of Rickettsia species in order to determine infection rates in ticks and to determine the Rickettsia species circulating in the country. We collected and pooled Hyalomma and Rhipicephalus ticks from two adjacent regions of Namibia (Khomas and Otjozondjupa) and observed an overall minimum Rickettsia infection rate of 8.6% (26/304), with an estimated overall pooled prevalence of 9.94% (95% CI: 6.5-14.3). There were no statistically significant differences in the estimated pooled prevalence between the two regions or tick genera. Based on the nucleotide sequence similarity and phylogenetic analysis of the outer membrane protein A (n = 9) and citrate synthase (n = 12) genes, BLAST analysis revealed similarity between Rickettsia africae (n = 2) and Rickettsia aeschlimannii (n = 11), with sequence identities ranging from 98.46 to 100%. Our initial study in Namibia indicates that both zoonotic R. africae and R. aeschlimannii are in circulation in the country, with R. aeschlimannii being the predominant species.

Assessing the adoption and application of the Namibian biosafety labelling regulations and determining their impact on Namibian food and feed importers.

The study was carried out to investigate the implications of the Namibian biosafety regulations on Namibian food and feed importers. After the Biosafety Act, 2006 (Act No. 7 of 2006), the biosafety regulation was gazetted in 2016, which saw the implementation of the national framework, the impact of food and feed importers was not known. The objective of the study was to assess the adoption and application of the national biosafety labelling regulations by food and feed importers. In addition, the impacts of these regulations on Namibian food and feed importers were assessed. The study used a structured online and hard copy survey questionnaire based on responses from 340 Namibian importers of food and feed products from eight identified Namibian regions: Khomas, Erongo, Kavango West, Kavango East, Omusati, Oshana, Ohangwena, Oshikoto, and Zambezi who have the knowledge required for the adoption and application of the Namibian biosafety labelling regulations. Using the Mann-Whitney test, the study confirmed that individuals who are aware of the biosafety Act, 2006 (Act No. 7 of 2006) are less likely to agree with statements such as experiencing problems in fulfilling requirements under the biosafety regulations. It was further concluded that there is a need to reduce the current administrative burdens for handling applications and improve dialogue between regulators and the food and feed importing industry while increasing the competence of regulators and creating more labelling regulation awareness for food and feed importers. The study further suggests that public awareness is required beyond food and feed importers.

Exploring the benefits of inoculated cowpeas under different climatic conditions in Namibia.

Cowpeas (Vigna uniculata L. Walp) are grown by many smallholder farmers in sub-Saharan Africa for food and their ability to fix nitrogen even under stress. Their performance depends on the indigenous rhizobial strains that live in symbiotic association with the roots; it can be enhanced if the seeds are inoculated with more effective ones. Data of the effectiveness of the technique under a variety of climatic conditions is rare. Here, we thus use a model to upscale two field experiments conducted in Namibia to include different climate change scenarios. The simulations show that non-inoculated cowpeas have mean yields of 0.5 t/ha and inoculated cowpeas 1 t/ha. If climatic conditions are favorable (cool and wet), estimated yield differences increase to over 1 t/ha. In dry years (< 200 mm), the average yield difference is only 0.1 t/ha. In the far future (2080-2100), instances of dry and hot years will increase. Using inoculated cowpea seeds instead of non-inoculated ones thus does not benefit farmers as much then as in the near future (2030-2050). In conclusion, using cowpea seeds inoculated with an efficient rhizobial strain can significantly increase yields under varying climatic conditions, but yield advantages decrease markedly in very dry and hot years.

Prevalence of pathogenic bacteria in street vended ready-to-eat meats in Windhoek, Namibia.

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.

Orphan Legumes Growing in Dry Environments: Marama Bean as a Case Study.

Plants have developed morphological, physiological, biochemical, cellular, and molecular mechanisms to survive in drought-stricken environments with little or no water caused by below-average precipitation. In this mini-review, we highlight the characteristics that allows marama bean [Tylosema esculentum (Burchell) Schreiber], an example of an orphan legume native to arid regions of southwestern Southern Africa, to flourish under an inhospitable climate and dry soil conditions where no other agricultural crop competes in this agro-ecological zone. Orphan legumes are often better suited to withstand such harsh growth environments due to development of survival strategies using a combination of different traits and responses. Recent findings on questions on marama bean speciation, hybridization, population dynamics, and the evolutionary history of the bean and mechanisms by which the bean is able to extract and conserve water and nutrients from its environment as well as aspects of morphological and physiological adaptation will be reviewed. The importance of the soil microbiome and the genetic diversity in this species, and their interplay, as a reservoir for improvement will also be considered. In particular, the application of the newly established marama bean genome sequence will facilitate both the identification of important genes involved in the interaction with the soil microbiome and the identification of the diversity within the wild germplasm for genes involved drought tolerance. Since predicted future changes in climatic conditions, with less water availability for plant growth, will severely affect agricultural productivity, an understanding of the mechanisms of unique adaptations in marama bean to such conditions may also provide insights as to how to improve the performance of the major crops.

Isolation and characterization of culturable seed-associated bacterial endophytes from gnotobiotically grown Marama bean seedlings.

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.

Molecular analysis of an endopolygalacturonase gene from a Eucalyptus canker pathogen, Cryphonectria cubensis.

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.

Prevalence and antimicrobial resistance pattern of Salmonella in animal feed produced in Namibia.

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 morama bean (Tylosema esculentum): a potential crop for southern Africa.

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.