Evaluation of genotype x environment interaction using GGE-biplot on dry beans (Phaseolus vulgaris L.) in Limpopo province of South Africa

Dry bean is the second most important legume crop in South Africa due to its high protein content. GGE- Biplot was used to evaluate genotype x environment interaction (GEI) and stability performance of dry bean genotypes during 2011 and 2012 growing seasons. Eight dry bean genotypes were planted at different locations in the Limpopo province, South Africa with different agro-climatic characteristics. The genotypes used were OPS-RS1, Jenny, Kranskop, DBS310, OPS-RS4, DBS 360, OPS-RS2 and OPS-RS5. The ANOVA analysis results for grain yield, number of pods per plant and number of seeds per plant revealed that the environment contributed more to the total variation followed by GEI and finally genotype. According to GGE biplot for grain yield, OPS- RS1 was regarded as the more stable genotype and had the highest mean yield, DBS 360 had the highest mean number of pods per plant and DBS 310 produced the highest mean number of seeds per plant. The GGE biplot methodology clearly presented the GEI relationship among environments and genotypes.The Limpopo Department of Agriculture and Rural developmenthttp://www.cropj.com/about.htmlam2017Plant Production and Soil Scienc

Effects of heat-moisture treatment on the thermal, functional properties and composition of cereal, legume and tuber starches: a review

Several methods are currently employed in the modification of starch obtained from different botanical sources. Starch in its native form is limited in application due to retrogradation, syneresis, inability to withstand shear stress as well as its unstable nature at varying temperatures and pH environment. Modification of starch is therefore needed to enhance its food and industrial application. A primary and safe means of modifying starch for food and industrial use is through hydrothermal methods which involves heat-moisture treatment and annealing. Heat-moisture treatment (HMT) is a physical modification technique that improves the functional and physicochemical properties of starch without changing its molecular composition. Upon modification through HMT, starches from cereals, legumes and tuber crops serve as important ingredients in diverse food, pharmaceutical and industrial processes. Although changes in starch initiated by HMT have been studied in starches of different plant origin, this work further provides insight on the composition, thermal and functional properties of heat-moisture treated starch obtained from cereals, legumes and tuber crops

The effect of drought stress on yield, leaf gaseous exchange and chlorophyll fluorescence of dry beans (Phaseolus vulgaris L.)

Global food production relies on irrigation, especially in low rainfall areas such as South Africa. The study was conducted to determine the effect of drought stress on growth, yield, leaf gaseous exchange and chlorophyll fluorescence parameters of dry bean under field conditions and the after effects of drought stress upon lifting drought stress. A rain shelter field trial was conducted at the Hatfield Experimental Farm of the University of Pretoria, Pretoria, South Africa. Dry bean cultivar DBS 360 was subjected to five levels of moisture stress arranged in a randomized complete block design with six replications. The plants were exposed to the following drought stress levels: the control: Irrigated to field capacity (S1), Withholding irrigation from 36 days after planting (DAP) for 24 days (S2), Withholding irrigation from 49 DAP for 24 days (S3), Withholding irrigation from 73 DAP to the end of the growing season (S4) and irrigated to field capacity on a fortnightly bases for the rest of the season from 36 DAP to the end of the growing season (S5).The results revealed that drought stress reduced dry matter production, leaf area index, number of pods per plant, number of seeds per plant, hundred seed weight and grain yield. Treatments S1, S4 and S5 produced statistically similar grain yield. Drought stress towards the end of the growing season may not cause serious harm in grain yield. Drought stress resulted in a reduction in photosynthetic rate, intercellular carbon dioxide concentration, stomatal conductance and transpiration. Chlorophyll fluorescence was also affected by drought stress. The highest WUE was found in the treatment which was irrigated on fortnightly bases from 36 DAP. This indicates that with appropriate irrigation it is possible to save water without a great yield loss in dry bean.http://www.elsevier.com/locate/agwat2018-01-31hb2017Plant Production and Soil Scienc

Expression of TN5 transposase for next generation sequencing protocol of HIV ad selected oncoviruses

MSc (Microbiology)Department of MicrobiologyObjective: The development of HIV drug resistance is a significant challenge in maintaining suppressed viral load in the management of patients. Next generation sequencing (NGS) is a more sensitive approach to determine the burden of HIV drug resistance. We aimed to describe the uptake of NGS in HIV drug resistance studies in Africa. Methodology: Electronic search was done for studies published between 2005 and 2019, from three databases: Pubmed, Web of Science and Google scholar. The search approach was carried out according to PRISMA guidelines. Studies included in the analysis were those that reported the use of NGS on HIV drug resistance using samples from Africa or in which the studies were done in Africa. Only articles published in English were included in the analysis. Results: Four thousand one hundred and eighty articles were identified according to the search criteria. Out of these, 238 studies met the inclusion criteria and were included in the analysis. Thirty studies (12.6%) used NGS, 194 (81.5%) used Sanger sequencing, and 14 (5.9%) used both techniques. Evidence of in-country application of NGS was observed in six studies (13.6%), all from South Africa. In other studies, NGS was either done outside of Africa using samples obtained from Africa or the country in which NGS was done was not indicated. From 2005 to 2012, only one study was reported on HIV drug resistance using NGS; however, 44 studies were published by 2019. Out of the 54 African countries, investigators from 13 countries (24.1%) published data on HIV drug resistance using NGS, as at end of 2019. Conclusion: There is an uptake in the application of NGS in HIV drug resistance studies in Africa, albeit in a slower pace, with investigators from about a quarter of African countries applying the technology for this purpose.NR

Influence of head-moisture treatment on functional, colour and thermal properties of bambara ground-nut starch

MSCFSTDepartment of Science and TechnologyHeat-moisture treatment (HMT) is a physical modification that alters the physicochemical properties of starch without changing its molecular structure. The objective of the study was to investigate the influence of HMT on the functional, colour and thermal properties of bambara groundnut (BG) starch. A central composite rotatable design comprising two independent factors (temperature and time) was used for the study. The central composite rotatable design was generated using Design-Expert software version 8.0.1.0. Bambara starch extraction was done by milling BG into flour (5 Kg), suspension in 15 L, 0.3% sodium hydroxide and centrifugation followed by washing using distilled water. The starch was then HMT treated in an air oven at 80 - 120 °C for 30 - 90 min under 15 % moisture content (MC) (HMT 15), 25% MC (HMT 25) and 35% MC (HMT 35). The highest L* and WI values for HMT treated BG starch were observed at HMT 80 °C for 30 min under 15% MC; 100 °C for 60 min (25% MC); and 100 °C for 17.57 min (35% MC) while the lowest was observed in HMT 100 °C for 102.43 min (15% MC); 120 °C for 90 min (25% MC); and 120 °C for 90 min (35% MC). In HMT 15-BG starch, the gelatinisation parameters onset (To), peak (Tp) and concluding temperature (Tc) of the samples decreased as treatment time and temperature increased whereas gelatinisation enthalpy of BG starch increased with increase in HMT treatment temperature and time. In HMT 25-BG starch Tp, and gelatinisation enthalpy of the starch increased with increase in HMT treatment temperature and time. While in HMT 35-BG starch, To, Tp, Tc and gelatinisation enthalpy of the starches decreased with increase in HMT treatment temperature and time. In HMT 15-BG starch, the water absorption capacity (WAC), solubility and swelling power (SP) decreased as treatment time and temperature increased while oil absorption capacity (OAC) of the starch increased with increase in HMT treatment temperature and time. In terms of HMT 25-BG starch, the WAC and OAC increased as HMT treatment time and temperature increased while SP and solubility of the starch decreased with increase in HMT treatment temperature and time. In HMT 35-BG starch, OAC, solubility and SP decreased as treatment time and temperature increased while WAC of the starch increased with increase in HMT treatment temperature and time. The optimum HMT conditions for BG starch were found to be 80 °C for 30 min (HMT 15), 105.74 °C for 30 min (HMT 25), and 113.16 °C for 30 min (HMT 35). Desirability of the obtained optimum conditions were 0.63 (HMT 15), 0.56 (HMT 25) and 0.64 (HMT 35). Information obtained from scanning electron micrograph indicates oval and round shape for bambara starch granules, with varying sizes. The range of the granule size width was 4.2 – 4.7 mm and 10 μm for length. The modified starches showed some changes in granule morphology as they seem to disintegrate with application of HMT. Unmodified and HMT - BG starches showed characteristic FTIR bands linked with common starches. All the samples displayed complex vibrations in the region below 1000 cm-1 due to the skeletal vibrations of the glucose pyranose ring. Statistical analysis on colour, thermal and functional properties of HMT 15-BG, HMT 25-BG and HMT 35-BG starch showed that effects of temperature and treatment time had no significant (p ≥ 0.05) effect on these properties of HMT-BG starch. However, treatment time had a significant linear effect (p ≤ 0.05) on swelling power, for HMT 15-BG starch. In HMT 35-BG starch, WAC was significantly affected by quadratic effect of temperature and time while solubility was significantly affected by linear effect of time and quadratic effect of temperature.NR

Maximizing dry bean (Phaseolus vulgaris L.) production through selected agronomic practices

Dry bean production in South Africa is lower than required for human consumption. Dry beans are rich in protein and thus an ideal replacement for expensive meat protein, especially for rural and poor communities in South Africa. To meet local demand, efforts to improve the yields obtained by small scale and subsistence farmers are needed. Therefore a series of experiments were conducted to investigate how dry bean production can be improved or optimized using selected agronomic practices. The objectives of the study were to determine the stability of dry bean varieties under the climatic conditions of Limpopo, to determine the impact of planting dry bean at lower or higher than recommended planting populations, to determine the effect of deficit irrigation and drought stress on dry bean production and to calibrate and validate SWB model in dry bean. The latter is of huge importance in South Africa where water resources are limited. The desirable genotype in terms of high mean yield was OPS-RS1 and the desirable environment in terms of high mean yield was Tshiombo irrigation scheme. The GGE biplot analysis resulted in meaningful and useful summary of GE interaction data and assisted in examining natural relationships and variations in genotype performance across tested environments. According to GGE biplot OPS-RS1 can be characterized as the genotype with the highest mean yield and high in stability. The results revealed that the interaction relationship between dry bean varieties and plant populations significantly influenced the grain yield per area, grain yield per plant, chlorophyll content, and plant height at 62 and 98 DAP (days after planting), while it affected dry matter production at 30, 62 and 98 DAP. The highest grain yield was achieved with OPS-RS2 at 150 000 plants per hectare (3.802 t ha-1) in 2012. The number of seeds per plant was influenced by plant population and dry bean variety. The number of pods per plant was only influenced by plant population. A plant population of 150 000 plants per hectare was found to be the most suitable for both determinate and indeterminate dry bean varieties. The introduction of deficit irrigation resulted in a significant reduction in plant height, number of seeds per plant and number of pods per plant. The reduction in number of seeds per plant and number of pods per plant resulted in a significant reduction in grain yield. The shelling % and 100 seed mass were not significantly influenced by deficit irrigation. Treatment S3 resulted in the poorest results throughout. The results revealed that deficit irrigation can result in substantial yield reduction in dry beans. There is thus a need for further research to develop drought tolerant varieties of dry beans. The introduction of drought stress resulted in a reduction in dry matter production, leaf area index, number of seeds per plant, number of pods per plant, seed size and finally grain yield. The treatments S2 and S3 performed poorly throughout. The results also revealed that 100 seed mass, number of pods per plant, number of seeds per plant, total dry matter yield at 92 DAP and leaf area were all positively correlated to grain yield. Water use efficiency was significantly affected by drought stress. The results suggest that drought stress towards the end of the growing season may not cause serious harm in grain yield. The results of the study indicate that drought stress effects on photosynthetic rate were highly significant, with a reduction of up to 45%. The reduction of photosynthesis at 63 and 105 DAP was greatly due to reduced stomatal conductance. Drought stress resulted in a reduction in intercellular carbon dioxide concentration, stomatal conductance and transpiration. Chlorophyll fluorescence was also affected by drought stress. The minimal chlorophyll fluorescence (F0) was increased by drought stress, accompanied by a reduction in the maximal chlorophyll fluorescence (Fm) and Fv/Fm. Drought stress can have serious effects on leaf gaseous exchange rate and chlorophyll fluorescence, depending on the growth stage of the plant and the duration of drought stress. The SWB model was successfully calibrated and validated for dry beans. The results revealed that the model can be used for scenario simulation for future planning.Thesis (PhD)--University of Pretoria, 2017.Plant Production and Soil SciencePhDUnrestricte

Development of a Budget Management Model for Managers in Public Hospitals in the Limpopo Province, South Africa

Budget management remains a challenge in public hospitals with regard to the delivery of cost effective health services. This article is based on a study undertaken to develop a budget management model for managers in public hospitals in the Limpopo Province of South Africa. The question is: How can the management of the budget in public hospitals be improved? The study investigates budget management in the public hospitals. The research methodology used for this study is both quantitative and qualitative research design to generate data required to achieve its aim and objectives. The targeted population for the study was all public hospitals in the Limpopo Province, which comprises 40 public hospitals. The findings showed that, as there is improvement in budget management, much needs to be done to improve budget management in the public hospitals. In this study a budget management model is recommended for consideration by managers

Optimisation of the techno-functional and thermal properties of heat moisture treated bambara groundnut starch using response surface methodology

This work optimised the techno-functional and thermal properties of heat moisture treated Bambara groundnut starch (BGS). A central composite rotatable design (Design-Expert software v8.0.1.0) comprising two independent factors of temperature and time was used. Extracted BGS were subjected to heat-moisture treatment (HMT) at 80–120 °C for 30–90 min at different moisture levels of 15% (HMT 15-BGS), 25% (HMT 25-BGS) and 35% (HMT 35-BGS). The optimum HMT conditions for BGS were found to be 80 °C for 30 min (HMT 15), 105.74 °C for 30 min (HMT 25), and 113.16 °C for 30 min (HMT 35). The desirability values of the obtained optimum conditions were 0.63 (HMT 15) and 1.00 (HMT 25 and 35). In HMT 35-BGS, water absorption capacity was significantly affected by the quadratic effect of temperature and time. In contrast, solubility was significantly affected by the linear effect of time and the quadratic effect of temperature. Temperature and treatment time had no significant effect (p ≥ 0.05) on the differential scanning calorimetry thermal properties of HMT 15, 25 and 35-BGS. Scanning electron micrographs of optimised BGS showed round and oval-shaped starch granules ranging from 4.2 to 4.7 mm (width) and 10 μm for length. Unmodified and optimised HMT–BGS showed characteristic FTIR bands linked with common starches. All BGS samples displayed multiple vibrations in the region below 1000 cm−1 due to the skeletal vibrations of the glucose pyranose ring

Prevalence and Molecular Epidemiology of Human Coronaviruses in Africa Prior to the SARS-CoV-2 Outbreak: A Systematic Review

Coronaviruses, re-emerging in human populations, cause mild or severe acute respiratory diseases, and occasionally epidemics. This study systematically reviewed human coronavirus (HCoVs) infections in Africa prior to the SARS-CoV-2 outbreak. Forty studies on the prevalence or molecular epidemiology of HCoVs were available from 13/54 African countries (24%). The first published data on HCoV was from South Africa in 2008. Eight studies (20%) reported on HCoV molecular epidemiology. Endemic HCoV prevalence ranged from 0.0% to 18.2%. The prevalence of zoonotic MERS-CoV ranged from 0.0% to 83.5%. Two studies investigated SARS-CoV infection, for which a prevalence of 0.0% was reported. There was heterogeneity in the type of tests used in determining HCoV prevalence. Two studies reported that risk factors for HCoV include exposure to infected animals or humans. The quantity of virologic investigations on HCoV on the African continent was scant, and Africa was not prepared for SARS-CoV-2