Molecular identification of viruses infecting maize (Zea mays L.) in Ekiti State, south-western Nigeria

Maize is one of the most commonly cultivated crops in southwestern Nigeria, but its production is constrained by virus diseases. Information on viruses infecting maize within the region is still limited. Therefore, a survey was conducted to identify the viruses infecting maize on randomly selected farmers' cultivated maize fields in 16 local government areas in Ekiti State, southwestern Nigeria using molecular detection tools. Four cultivated maize fields were randomly surveyed in each local government area with an average size of 50 m x 50 m. The sampling was done on fifty randomly selected plants per field. Viral diseases were confirmed on maize plants through visual symptoms observations and serological diagnosis, although severity and incidence varied per location. Visible symptoms observed include chlorotic patches, severe streaking, red pigments and venation along mid rib and vein with stunted growth. Although only Maize streak virus (MSV) and Maize chlorotic mottle virus (MCMV) were targeted, serological assay indicated the occurrence of only MSV. Polymerase chain reaction (PCR) confirmed the presence of MSV while MCMV was negative. This provides additional information to the prevalence of MSV as an ongoing threat to maize production in southwest Nigeria.Keywords: Maize streak virus, Maize chlorotic mottle virus, ELISA, Polymerase chain reaction, Symptom

Agro-ecological incidence and severity of Pepper veinal mottle virus, genus Potyvirus, family Potyviridae, on cultivated pepper (Capsicum annuum L.) in Nigeria

A survey for the agro-ecological distribution of Pepper veinal mottle virus (PVMV) (Family Potyviridae, genus Potyvirus) its incidence and severity on cultivated pepper was conducted between 2003 to 2005 in six agro-ecological zones in Nigeria, comprising the major pepper producing areas of the humid forest, derived savanna, southern Guinea savanna, mid-altitude, northern Guinea savanna and Sudan savanna The virus was isolated and its physical properties determined.PVMV was confirmed to be present in cultivated pepper fields in the six agro-ecological zones surveyed but with significant difference in disease incidence and severity within the agro-ecological zones. Out of the three thousand suspected viral infected pepper leaves sample collected from the fields in the six agro-ecological zones, 88% were confirmed to be PVMV positive through the serological test while 12% were found to be negative. The Electron micrograph photograph showed antiserum decorated PVMV particles, having flexuous filamentous particles of 750nm in length and 10 nm wide. The thermal inactivation point of the virus was 70OC and still infective up to the 12th day, while the dilution end point in which PVMV extract from Capsicum annuum L. was still infective was 10-4.The incidences of PVMV diseases were observed to be high in the derived savanna and the humid forest compared with the other agro-ecological zones. The percentage PVMV disease incidence ranged between 39.14% with 34.48% severity in the Sudan savanna to 50.12% incidence and 43.85% severity in the derived savanna zone. The high incidence and severity of PVMV in these two agro-ecological zones that are characterized by thick vegetation and warm humid climate, with the presence of many secondary host plants for the virus. suggest that ecological characteristics, climate and vegetation in the different ecological zones appeared to play a major role in determining the incidence and severity of PVMV infection on pepper in the fields.Keywords: Pepper veinal mottle virus, Incidence, Severity, Pepper, Agro-ecological, Zone

Multinational Corporations\u27 Return on Investment Optimization in Nigeria\u27s Business Environment

Trade between the United States and Africa decreased 32% from US$125 billion, in 2011, to US$85 billion, in 2013; however, MNCs from other regions have continued to increase investments in Africa. Multinational corporations (MNCs) generate most of their return on investment (ROI) from the Western world. Globalization, increasing middle classes in emerging markets, and decreasing population in the Western world have lead to unsustainable ROI. Nigeria, the most populous and largest economy in Africa and the 27th largest economy in the world, offers new opportunities with an annual growth rate forecast of 6% to 8%. Utilizing the diamond theory of competitive advantage of nations, this single case study was an exploration of the strategies that managers of MNCs have used to optimize Nigeria\u27s higher ROI. Interview questions on new entry challenges, operational obstacles, and strategies to mitigate the challenges contributed to answering the overarching research question related to the strategies that managers of MNCs have used successfully to take advantage of Nigeria\u27s high ROI. The participants were 5 executives at the Nigerian operation of a global technology conglomerate with presence in 166 countries. Data collection included a series of semistructured face-to-face interviews. Data analysis using modified van Kaam method resulted in 5 themes: business environment, effective entry strategies, challenges in Nigeria, mitigating challenges in Nigeria, and volatility of Nigerian market and mitigation strategies. Findings may contribute to ROI optimization and influence social change by providing more jobs, thereby increasing standard of living in Nigeria

Agro-ecological incidence and severity of Pepper veinal mottle virus, genus Potyvirus, family Potyviridae, on cultivated pepper (Capsicum annuum L.) in Nigeria.

A survey for the agro-ecological distribution of Pepper veinal mottle virus (PVMV) (Family Potyviridae, genus Potyvirus) its incidence and severity on cultivated pepper was conducted between 2003 to 2005 in six agro-ecological zones in Nigeria, comprising the major pepper producing areas of the humid forest, derived savanna, southern Guinea savanna, mid-altitude, northern Guinea savanna and Sudan savanna The virus was isolated and its physical properties determined. PVMV was confirmed to be present in cultivated pepper fields in the six agro-ecological zones surveyed but with significant difference in disease incidence and severity within the agro-ecological zones. Out of the three thousand suspected viral infected pepper leaves sample collected from the fields in the six agro-ecological zones, 88% were confirmed to be PVMV positive through the serological test while 12% were found to be negative. The Electron micrograph photograph showed antiserum decorated PVMV particles, having flexuous filamentous particles of 750nm in length and 10 nm wide. The thermal inactivation point of the virus was 70OC and still infective up to the 12th day, while the dilution end point in which PVMV extract from Capsicum annuum L. was still infective was 10-4. The incidences of PVMV diseases were observed to be high in the derived savanna and the humid forest compared with the other agro-ecological zones. The percentage PVMV disease incidence ranged between 39.14% with 34.48% severity in the Sudan savanna to 50.12% incidence and 43.85% severity in the derived savanna zone. The high incidence and severity of PVMV in these two agro-ecological zones that are characterized by thick vegetation and warm humid climate, with the presence of many secondary host plants for the virus. suggest that ecological characteristics, climate and vegetation in the different ecological zones appeared to play a major role in determining the incidence and severity of PVMV infection on pepper in the fields

THE EFFECT OF AGRO-ECOLOGICAL ZONES ON THE INCIDENCE AND DISTRIBUTION OF APHID VECTORS OF PEPPER VEINAL MOTTLE VIRUS, ON CULTIVATED PEPPER (CAPSICUM ANNUUM L.) IN NIGERIA

The distribution of aphid vectors of Pepper veinal mottle virus (PVMV) was studied on cultivated pepper between 2003 and 2005 in the major pepper producing areas of the six agro-ecological zones in Nigeria. The aphids were isolated, identified and their transmission ability determined. Population of aphid vectors increased progressively in all the agro-ecological zones from March at the onset of raining season reaching a peak in August and then declining from September at the on set of the dry season. The Humid forest and Derived Savanna agro-ecological zones recorded highest mean population of aphids / leaf and types of aphid’s species compared with other agro-ecological zones. Six species of aphid, Myzus persicae (Sulzer), Aphis gossipii (Glover), Aphis craccivora (Koch), Aphis spiraecola (Patch), Aphis fabae (Blanchard), and Rhopalosiphum maidis (Fitch), were identified on the pepper fields surveyed in all the agro-ecological zones. There was no significant difference in the occurrence of M. persicae, A. gossipii, A. craccivora, and R. maidis while A. spiraecola and A. fabae that varied in occurrence in all the zones. Ability to transmit PVMV to a healthy pepper plants varied in all the identified aphid species but R. maidis was not able to transmit PVMV from infected to a healthy pepper plant. A more sustainable approach to controlling pepper viruses is by targeting the aphid vectors and preventing the vectors from reaching the crops because the aphid vectors which are virus specific are the major means of transmitting virus to healthy plant

Short Communication Report: An analysis of Human African Trypanosomiasis (HAT) in Nigeria.

No Abstrac

Propagation of Coleonema album (Thunb.) Bartl. & J. C. Wendl. : a horticultural and medicinal plant.

Thesis (M.Sc.)-University of KwaZulu-Natal, Durban, 2012.Coleonema album is a South African green treasure, endemic to the Cape region and hard to find in other parts of the country. It is ranked among the most highly utilized medicinal plants at present. The plant extracts exhibit a wide range of pharmacological activities due to its bioactive compounds. Immunat, a tincture from this plant is marketed commercially. Medicinal plant gatherers are on the lookout for this plant due to its high demand and market price. Several natural product companies in South Africa are now exporting Coleonema album oil. Its showy beautiful white flowers make it a valuable ornamental plant. There is no accredited germination protocol available for this medicinal and ornamental plant till date. In this study, the chemical and environmental conditions required for optimum seed germination and seedling growth were studied. The effect of light, temperature shifts, cold and warm stratifications, smoke-water, butenolide, pH levels, plant growth regulators (kinetin, 6-benzyladenine, indole acetic acid and α-Naphthalene acetic acid), salt solutions (sodium chloride and ammonium nitrate) on seed germination were investigated. Seeds showed favourable response of germination at low temperatures (10 and 15 ºC). Seeds exposed to continuous darkness at low temperatures showed highest germination at 15 ºC. Temperature shift (from 20 ºC to 15 ºC) favoured seed germination. pH 6 is the most conducive pH level for Coleonema album seed germination (52.5%). Sodium chloride and ammonium nitrate solutions (pretreatment for 2 weeks) significantly improved germination at a 10-2 M concentration with 62.5 and 75% germination respectively. Coleonema album seeds exhibit a temperature-dependent physiological dormancy. Seed germination of this plant is quite erratic as seed germination started 21 days after incubation and lasted for over 90 days. Germination rate of the seeds is too slow to meet the local and international demand for this plant. Plant tissue culture techniques have been used as an alternative for mass cultivation of plants that are difficult to propagate from seeds. Therefore, an effective micropropagation protocol was developed as a measure to conserve this highly utilized medicinal plant. The effects of the cytokinins: BA, kinetin, TDZ and topolins on in vitro shoot formation of Coleonema album were investigated. Of all the cytokinins tested, 5 μM mT gave the highest number of shoots (14.50) per explant. Combination of 5 μM mT with various concentrations of IBA and NAA significantly increased shoot production. Shoots cultured on IBA supplemented medium produced roots. Root production from NAA cultures is unfavourable as most of the shoots developed callus at the base of the stem. The result of this study has shown that mT has potential as a highly active alternative to BA and other cytokinins for Coleonema album in vitro shoot production. Over 1,000,000 plantlets could be produced annually using the in vitro propagation protocol developed in this study. The results of this study will be useful as a guide for mass cultivation of this ornamental and medicinal plant. It will also provide an opportunity for propagation of Coleonema album in other parts of the country. By virtue of this, the pressure on the wild population of this species could be greatly reduced

Effect of Rutaceae plant's essential oils and leaf extracts on dermatophytic fungal cell morphology : a hope for the development of an effective antifungal from natural origin.

Ph. D. Botany. University of KwaZulu-Natal, Pietermaritzburg 2016.Abstract available in PDF file

Comparative bone marrow responses of albino rats experimentally infected with single and mixed species of Trypanosoma congolense and Trypanosoma brucei and ability to control anaemia

Effect of Trypanosoma congolence and T. brucei mixed infection on ability of the bone marrow to respond to anemia was investigated in albino rats. This was with the view of assessing the possible impact on recovery rate from anemia following chemotherapy of African trypanosomosis. The investigation involved descriptive evaluation of packed cell volume and corresponding bone marrow cytological changes associated with single and mixed infection of T. congolense and T. brucei. It involved laboratory based experimental infection of albino rats as research models. A total of 32 adult albino rats of mixed sexes were used for this investigation. The rats were randomly grouped into three groups, A, B, C made up of 8 rats each, and infected with T. congolense, T brucei and mixed infection of these species.. Eight other rats served as the uninfected control group.Parameters measured included weekly packed cell volume (PCV) and differential bone marrow cytology of the different groups of infected and control rats at the end of 21 days post infection (PI). At the end of 21 days PI, the anemia characterized by drop in PCV was most severe in the mixed infection group, and least in T. brucei group with tendency for self-recovery from anemia. The bone marrow responses in the mixed infection group was however weak and inferior to that of T. brucei and T. Congolense groups. Poor erythropoietic response in the mixed infection group despite significant fall (P < 0.05) in PCV level was believed to arise from severe renal and hepatic pathology resulting to subnormal erythropoietin release and severe stem cell injury. This is believed would cause longer time to be taken by mixed infection animals to recover from anemia after chemotherapy. It is concluded that T. congolense and T. brucei mixed infection result to marked incapacitation of the bone marrow and ability for recovery from anemia. This suggests that supportive administration of synthetic erythropoietin may be required in trypanosome specie mixed infection situation due to severe pathological effects on the kidney and liver resulting to impaired erythropoietinbiosynthesis and slow recovery from anemia following chemotherapy in African trypanosomiasis.Keywords: Anemia, bone marrow, mixed infection, rats, trypanosomiasis, erythropoieti