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Abstracts
Heavy metals contamination in the environment is a concern worldwide. Most of the methods already in use to clean up the environment from these heavy metals are costly and difficult to get optimum results. Currently; focus is on phytoremediation as an effective and affordable solution. This study evaluated the heavy metal uptake potential of Egeria densa (a submerged plant) as a possible candidate in phytoremediation of polluted water. Concentrations of heavy metals [Cadmium (Cd), copper (Cu), iron (Fe), lead (Pb), manganese (Mn), and zinc (Zn)] in water, sediments and E. densa plant samples of two ponds were evaluated. Pb, Fe, Mn, and Cu contents were very high in the water samples of both ponds and raged from 0.104 to 35.36 mg/L, while Cd and Zn were not detected. Evaluation of the sediments from both ponds revealed that Fe contents were high in the sediments of both ponds and Cu contents were very low. Heavy metal content in E. densa plant samples from both ponds showed that manganese was high in plant sample from pond 1, while zinc concentration was greater in plants sample from pond 2. These results suggested that E. densa has the potential to accumulate heavy metals especially Mn and Zn. doi:10.1016/j.sajb.2016.02.106
Antidiabetic and cytotoxic activities of Aloe ferox Mill R. Mhaladi, I.T. Madamombe-Manduna, S.S. Mashele Drug Discovery Unit, Department of Health Sciences, Central University of Technology, Free State, Private Bag X20539, Bloemfontein 9300, South Africa With over 86 recorded uses, Aloe ferox Mill. is part of a multimillion dollar business that is rapidly growing and a major interest in the pharmaceutical industry. It is for that reason that more research must be done to prove and validate its use and safety and in the process discover even more medicinal benefits. This project focused on investigating the antidiabetic and cytotoxic potential of A. ferox methanoic and aqueous extracts. The C2C12 muscle cells were grown in Dulbecco's Modified Eagle Medium (DMEM) with 10% foetal bovine serum at 37 °C in humidified air with 5% CO2. Chang cells were grown and maintained in Eagle's Minimal Essential Medium (EMEM) at 37 °C with 10% foetal bovine serum with 5% CO2 humidified air. Both were used to model and determine the effect of A. ferox extracts on glucose uptake. Mosmann Tetrazole Test (MTT) and the Sulforhodamine B assays were used to determine the cytotoxic effects of the extracts on C2C12 muscle and Chang cells and normal human foetal lung fibroblasts. The extracts enhanced glucose uptake in the C2C12 cells from 100 μg/ml to 109.57 μg/ml (methanoic) and 138 μg/ml (aqueous) which was more effective than the vehicle control Metformin. The extracts caused an insignificant decrease in glucose uptake by Chang cells from 100 μg/ml to 90 μg/ml (aqueous) and 98 μg/ml (methanoic). Both extracts did not show any toxicity to the normal cells they were tested against. The extracts caused only an insignificant decrease in cell viability deeming it a very low hazard. doi:10.1016/j.sajb.2016.02.107
c
University of the Free State, PO Box 339, Bloemfontein 9301, South Africa
Sugarcane requires 12:30 h day-length and N21 °C for flowering and fertile pollen production. At the South African Sugarcane Research Institute in KwaZulu-Natal, where sugarcane breeding is undertaken, these conditions are manipulated in controlled facilities as they do not occur naturally. The objectives were to evaluate the effect of photoperiod treatments on time to flowering and pollen production by genotypes over 19 years. Glasshouse (G) and photoperiod house (P) treatments were designed to differ in the time of artificial dawn and in incremental lengths to maintain the 12:30 h day-length. The data collected and analysed (variance analyses) were (a) natural date to flowering (number of days to panicle emergence) and (b) percentage pollen stain (starchiodine stain). There were significant (P b 0.0001) differences among photoperiod treatments for time of flowering and pollen viability by genotypes. The genotypes in P treatments produced more fertile pollen and delayed flowering (53–64% viability and 179–188 days to flowering) than in the G treatments (39–51% viability and 158–183 days to flowering). Since sugarcane pollen is only viable for 20 min, it is desirable that flowers to be used as ‘male parents’ from the P treatments should flower later than the ‘female parents’ in the glasshouse as stigma receptivity generally lasts for 7 days. Although synchronisation among genotypes was partially achieved, the flowering times still need to be narrowed to enhance the production of hybrids. doi:10.1016/j.sajb.2016.02.108
The comparison of the uses of Sclerocarya birrea (A Rich.) Hochst. subspecies caffra (Sond) among the Bapedi and the Vhavenda cultural groups in the Limpopo Province, South Africa T.A. Mocheki, M.H. Ligavha-Mbelengwa Department of Botany, School of Mathematical and Natural Sciences, University of Venda, Private Bag X5050, Thohoyandou 0950, South Africa Sclerocarya birrea is one of the most commonly used fruit-bearing tree species found throughout sub-Saharan Africa. It is one of the most highly valued indigenous trees of Southern Africa due to its wide variety of uses and its multifaceted uses which are recognised as commercially, medicinally and culturally important in Africa. It is widely used by local communities as a source of food and for ethnomedicinal as well as cultural practices. The main aim of this study was to compare the uses of S. birrea among the Bapedi and Vhavenda people. The study was conducted in the Limpopo Province whereby one village per cultural group was visited and 30 homesteads were randomly selected per village. To get the information about the uses of S. birrea a questionnaire was used. The results showed that the Bapedi cultural group has a higher number of uses for the fruits and the stem than the Vhavenda cultural group, whereas the Vhavenda cultural group has higher number of uses for the bark than the Bapedi cultural group. Both cultures have an equal number of uses for the leaves and roots of S. birrea. The fruits were mostly used by both cultures since they have the highest number of uses in both cultures followed by the bark. doi:10.1016/j.sajb.2016.02.109
Assessment of photoperiod treatments on flowering and pollen production in a sugarcane breeding programme in South Africa N.Y. Mhlongoa,b, M.M. Zhoua,c, S.J. Snymana,b, M.P. Wattb a South African Sugarcane Research Institute, Private Bag X02, Mount Edgecombe 4300, South Africa b University of KwaZulu-Natal (Westville Campus), School of Life Sciences, Private Bag X54001, Durban 4000, South Africa
Effect of P-fertilization and Bradyrhizobium-inoculation on nodulation and growth of cowpea at Mbombela, South Africa M.S. Mochosaa, S.T. Masekoa, F.D. Dakorab a Department of Crop Sciences, Tshwane University of Technology, 175 Nelson Mandela Drive, Private Bag X680, Pretoria 0001, South Africa
Abstracts b
Department of Chemistry, Tshwane University of Technology, 175 Nelson Mandela Drive, Private Bag X680, Pretoria 0001, South Africa The application of P-fertilizers to cowpea or its inoculation improves its growth and yield. Synthetic P-fertilizers as well as rhizobial inoculants are accessible in South Africa; however, these are hardly used by smallholder farmers. This study was conducted at the Mbombela campus of the University of Mpumalanga to evaluate the effect of application of 10 or 20 kg P/ha, P application with Rhizobium-inoculation as well as Rhizobium inoculation to nodulation and growth of cowpea genotypes IT98K205-8 and IT99K529-1. At the flowering stage, plants were dug out and nodules counted whilst shoots were packed in paper sample bags, oven-dried and weighed. Bradyrhizobium-inoculated plants had significantly more nodules than un-inoculated controls. Furthermore, Bradyrhizobium-inoculated plants fertilized with 10 kg P/ha exhibited greater nodule number. Nodule dry weight of Bradyrhizobium-inoculated cowpea plants was significantly greater than that recorded in un-inoculated controls. In general, Bradyrhizobium-inoculated cowpea plants established with the application of 20 kg P/ha recorded significantly higher nodule dry weight that their counterparts. The results also revealed that cowpea plants of both test genotypes that were inoculated grew significantly better than their un-inoculated counterparts. Overall, the test cowpea plants grown with Bradyrhizobium-inoculation grew best than their un-inoculated counterparts where established with the application of 10 and 20 kg P/ha. Results from the field experiment generally showed that, Bradyrhizobium-inoculation as well as inoculation with application of 10 or 20 kg P/ha improved nodulation and growth of plants of the IT98K 205-8 and IT99K 529-1 cowpea genotypes at Mbombela.
doi:10.1016/j.sajb.2016.02.110
Amino acid and mineral composition of indigenous watermelon (Citrullus lanatus (Thunb) Matsum. and Nakai)) landrace seeds from the Sekhukhune and Capricorn districts in the Limpopo Province E.A. Mogotlane, P.W. Mokwala Department of Biodiversity, School of Molecular and Life Sciences, University of Limpopo, Private Bag 1106, Sovenga 0727, South Africa Watermelons are one of the major underutilised fruits grown in the warmer parts of the world. Watermelon seeds are high in protein content and are naturally complete with essential amino acids. Seeds of the watermelon are said to contain considerable amounts of minerals, which assist in growth and development of a healthy body. Amino acids were hydrolysed according to the method of the Association of Official Analytical Chemists and identified using thin layer chromatography. Iron, zinc and copper were determined by atomic absorption spectrometry. Sulphur was determined gravimetrically as barium–sulphate while calcium was determined using titrimetry. It was found that leucine is the most abundant amino acid in watermelon landrace seeds. Landraces from Capricorn district were found to have a high content of copper (0.078 mg/g) and zinc (0.231 mg/g). The presence of the amino acids indicates that the seeds can be a good food supplement for infants. Landrace seeds have showed to contain sufficient quantities of minerals and essential amino acids to have the potential to meet the nutritional needs of many people in developing countries.
doi:10.1016/j.sajb.2016.02.111
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Variations in N2 fixation of field-grown Kersting's groundnut (Macrotyloma geocarpum) landraces in response to inoculation with two Bradyrhizobium strains in the northern region of Ghana M. Mohammeda, E.N.K. Sowleyb, F.D. Dakorac a Department of Crop Sciences, Tshwane University of Technology, 175 Nelson Mandela, Private Bag X680, Pretoria 0001, South Africa b Department of Agronomy, University for Development Studies, PO Box TL 1882, Tamale, Ghana c Department of Chemistry, Tshwane University of Technology, 175 Nelson Mandela, Private Bag X680, Pretoria 0001, South Africa Studies of N contribution by the legume-Rhizobium symbiosis have neglected under-utilized crops such as Kersting's groundnut. The present study assessed N2 fixation of eight Kersting's groundnut landraces in response to inoculation with two Bradyrhizobium strains (Bradyrhizobium japonicum CB756 and Bradyrhizobium sp. BR3267) at two locations (Savelugu and Tamale) in the northern region of Ghana. At early podding, plants were assessed for nodulation and shoot biomass. Oven-dried shoot samples were ground (0.5 mm sieve) and subjected to 15N isotopic analysis to determine N2 fixation. The landraces exhibited marked variations in nodule functioning as evidenced by differences in their shoot δ15N values. As a result of their lower δ15N values, most landraces in the present study obtained more than 60% of their N requirements from atmospheric N2 fixation. The amounts of N-fixed by the landraces closely mirrored patterns of plant growth and shoot N accumulation. Values of N-fixed ranged between 41 to 72 kg N ha− 1. There was a tendency for both Bradyrhizobium strains to decrease the δ15N values of plants at both locations relative to the un-inoculated plants, translating into greater dependence on N2 fixation by the inoculated plants at both locations. Analyses of interaction effects suggest differences in N2-fixing efficacy of indigenous rhizobia between the two locations, as well as possible variations among landraces in their choice of microsymbionts. doi:10.1016/j.sajb.2016.02.112
Antimicrobial activity of extracts and fractions of Hermannia geniculata Eckl. & Zeyh. against selected bacteria and fungi P.J. Mojau, A.O.T. Ashafa Phytomedicine and Phytopharmacological Research Group, Department of Plant Sciences, University of the Free State, Qwaqwa Campus, Private Bag X13, Phuthaditjhaba 9866, South Africa Hermannia geniculata has been used widely as traditional medicine for treatment against infectious human pathogens. The aim of the study was to determine the antibacterial and antifungal activities of H. geniculata root extracts and their fractions against 16 microbial strains. The dried plant materials were extracted separately in 150 ml of methanol, acetone, ethanol, water and 150 ml (50/50) of hydroethanol. Acetone extract inhibited the growth of microorganisms with minimum inhibitory concentration (MIC) values of 1.56 mg/ml against all the tested strains except for Salmonella typhimurium and Candida rugosa at the concentration of 6.25 mg/ml. The ethanol, hydro-ethanol and methanol extracts inhibited bacterial growth with MIC values ranging from 3.13 mg/ml to 12.50 mg/ml, whilst water extract had MIC of 12.50 mg/ml against all tested bacterial and fungal strains. Acetone extract had maximum bactericidal concentration (MBC) values ranging from 1.56 to 3.13 mg/ml against most microorganisms. Butanol fraction of acetone extract had MIC of 0.78 mg/ml against Staphylococcus aereus (OK2b) and Staphylococcus aureus (ATCC 6538), whilst the ethyl acetate had the lowest MBC of 1.56 mg/ml against S. aereus (OK2b), S. aureus