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A framework addressing barriers to utilization of Elimination of Mother- to -Child Transmission of HIV services among pregnant women and lactating mothers in Gauteng Province
No full textPhD (in Public Health)Elimination of mother-to-child transmission of HIV (EMTCT) is a global health priority, ensuring that no child is born with HIV. Poor utilization of EMTCT services leads to burdensome consequences such as vertical transmission of HIV and an increase in maternal and neonatal mortality rates. Despite the progress made to reduce new HIV infections in children, barriers to the utilization of the Elimination of Mother-to-Child Transmission service remain the bottleneck that affects the program’s effectiveness. Pregnant and lactating women face many challenges that can contribute to loss of follow-up during their prenatal and postnatal care.
This study developed a framework to enhance the utilization of the Elimination of Mother-to-Child Transmission of HIV services among pregnant women and lactating mothers in Gauteng province. A convergent parallel mixed methods design was used, where exploratory-descriptive qualitative approaches were concurrently run with the quantitative approach employing a cross-sectional descriptive design. A convenience sampling method was used to select these women based on accessibility and availability, ensuring the study's comprehensive coverage. A self-administered questionnaire was utilized to assess 681 pregnant and breastfeeding women. The data was analyzed using descriptive statistics using STATA 15.0. Validity and reliability issues were considered in the study to ensure the consistency of the work. For the qualitative approach, a convenience and purposive sampling method was used to select eligible pregnant and lactating women. A semi-structured interview guide was used to collect data until data saturation occurred after interviewing 25 participants. Qualitative data was analyzed thematically. Trustworthiness was ensured through Credibility, Confirmability, Transferability, and Dependability for the quantitative approach. Ethical principles were adhered to throughout the study. The findings were conceptualized using the health belief model.
The results were interpreted and integrated. The combined qualitative and quantitative data gave a deeper understanding of the barriers to EMTCT utilization and perceived strategies to enhance its utilization. Strengths, Weaknesses, Opportunities, and Threats analysis were employed to guide the development of the framework using the BOEM model. Validation of the developed framework was done through stakeholder consultations and the Delphi technique. Experts and stakeholders participated in the process of validating and confirming the effectiveness of the developed framework to enhance the utilization of EMTCT services in Gauteng province. The framework can improve the utilization of EMTCT services among pregnant and lactating women with continued efforts to enhance the accessibility and utilization of EMTCT services, promoting the health and well-being of both mothers and their children. It is believed that the implementation of the developed framework will benefit all women of childbearing age throughout Gauteng province
Thuthuwedzo ya tshofhinga tsha tshanduko ya kumalele kwa Vhavenda: ho sedzwa lumalo
No full textMA in TshivendaDepartment of African LanguagesṰhoḓisiso iyi yo ḓisendeka kha tshanduko ya kumalele kwa Vhavenḓa zwo ṱuṱuwedzwa nga tshifhinga tshine ra khou tshila khatsho. Zwithu zwi khou ḓi shanduka zwi tshi ya na tshifhinga, naho tshanduko i tshi tea u vha hone ndi zwa ndeme u tevhela maitele oṱhe a mvelele yau. Thaidzo ya ṱhoḓisiso iyi ndi u shanduka ha lumalo u bva kha u vhumba vhushaka vhukati ha miṱa mivhili u ya kha vhushaka ha tshifhinganyana. Ndivho ya ṱhoḓisiso iyi ndi u bvisela khagala masiandoitwa a tshanduko ya lumalo lwa Vhavenḓa zwine zwo ṱuṱuwedzwa nga tshifhinga tsha musalauno. Kha ṱhoḓisiso iyi ho shuma thyori ya modenaizesheni ine i amba nga ha tshanduko ya matshilele a vhathu na zwithu. Ṱhoḓisiso iyi ndi ya lushaka lwa khwaḽithethivi. Muṱoḓisisi o kuvhanganya mafhungo awe kha vhathu vhane vha vha na nḓivho na tshenzhemo nga ha tshanduko ya lumalo lwa Vhavenḓa. Afha muṱoḓisisi o kuvhanganya mafhungo awe nga nḓila ya inthaviyu. Muṱoḓisisi o shumisa ṱhumbulo i si na khonadzeo ya u nangiwa (nonprobability sampling) ine ya dovha ya vha na matavhi o fhambanaho a ngaho ṱhumbulo yo livhaho (purposive sampling) vhunga hu tshi ḓo nangiwa vhathu vhane vha vha na nḓivho na tshenzhemo nga ha kumalele kwa Vhavenḓa. Afha vhavhudziswa ndi vhakalaha, vhakegulu, vhafunzi, vhavhera, vhabvana, vhanna na vhafumakadzi vha mbingano ntswa na vhomakhadzi. Vhavhudziswa avho ndi vhane vho nangiwa uri vha ḓo ṋea mafhungo a ndeme nga ha tshanduko ya kumalele kwa Vhavenḓa vhunga vhe na nḓivho na tshenzhemo. Ṱhoḓisiso iyi yo itwa kha vunḓu ḽa Limpopo kha tshiṱiriki tsha Vhembe fhasi ha masipala wa Thulamela, muvhunduni wa Itsani. Ṱhoḓisiso iyi i ḓo fhaṱusa vhathu vhoṱhe vhane vha khou tea u malisa uri vha ḓivhe nga ha kumalele kwo teaho khathihi na u wana nḓivho nga ha maitele oneone o teaho a kumalele kwa mvelele ya Vhavenḓa
The assessment of water supply system efficiency and water quality in Standerton, Lekwa Municipality, Mpumalanga, South Africa
No full textMENVSCI in Hydrology and Water ResourcesDepartment of Earth SciencesMost municipalities in South Africa face significant challenges in managing their water treatment plants effectively, often due to a lack of technical expertise, insufficient staffing and poor maintenance planning. These result in poor water quality, frequent supply interruptions and failure to comply with regulatory standards. Furthermore, difficulties in retaining skilled personnel and misallocation of resources exacerbate the problem, exposing communities to health risks and unreliable water services that undermine sustainable water supply efforts. This study evaluated the efficiency of the water supply system and assessed water quality at the Standerton Water Treatment Plant (SWTP) in Lekwa Local Municipality, Mpumalanga, South Africa. The assessment focused on operational performance, distribution effectiveness and compliance with national and international water quality standards. Data were collected through field observations, water meter readings and five years of water quality data obtained from the Department of Water and Sanitation (DWS) Mpumalanga from 2016 to 2020. Efficiency analysis involved comparing water quantity against demand, quantifying water losses and assessing distribution reliability. Water quality was evaluated by comparing measured parameters to guidelines set by the World Health Organization (WHO), South African National Standard (SANS-241), and Department of Water Affairs (DWA). Parameters analyzed included microbiological indicators such as Escherichia coli and total coliforms, as well as physicochemical variables like pH, turbidity, free chlorine, electrical conductivity (EC), total dissolved solids (TDS), manganese (Mn), and iron (Fe). The results showed that pH, EC, and TDS consistently met the acceptable limits throughout the five-year period, indicating stable performance in these aspects. However, free chlorine, turbidity, manganese and iron persistently exceeded regulatory limits, signaling systemic issues within the treatment process. These ongoing exceedances point to challenges such as inadequate chemical dosing, poor filtration, ineffective disinfection and possible contamination within the distribution network. Of particular concern was the detection of E. coli, suggesting faecal contamination and increased risk of waterborne diseases. The elevated turbidity, Mn and Fe levels also affected water aesthetics, leading to consumer complaints and diminished trust in the municipal water supply. Operational challenges identified include aging infrastructure, poor maintenance practices, inaccuracies in chemical dosing and delayed responses to equipment failures such as
malfunctioning pumps and burst pipelines. The plant operates beyond its designed capacity; although licensed for 27 ML/day with a design capacity of 37 ML/day, SWTP treated 43 ML/day while the estimated demand was approximately 45 ML/day. This overcapacity strains the plant, contributing to the suboptimal treatment performance. Additionally, the plant did not comply with regulatory requirements mandating the measurement of critical parameters pH, turbidity and EC at two-hour intervals, due to a lack of necessary analytical equipment. Staffing issues were prevalent, with many process controllers lacking formal training and qualifications necessary for effective plant management. The study also highlighted real-world impacts on local businesses, such as Goldie Chicken, which experiences water outages lasting up to two days per week. These interruptions have resulted in reduced production, workforce retrenchment and the inability to meet market demand. To improve water service delivery, it is imperative for the municipality to invest in upgrading water treatment infrastructure, ensure that plant personnel meet minimum qualification standards and implement continuous training programs to build technical capacity. Strengthening operational management and maintenance practices is essential to achieving regulatory compliance, safeguarding public health and securing a sustainable water supply for the Standerton community.Department of Water and Sanitatio
Effectiveness of flood response mechanisms for enhancing resilient livelihoods in Tsholotsho District of Zimbabwe
No full textPhD (Rural Development)Institute of Rural DevelopmentFlooding is a recurrent natural disaster that disrupts livelihoods, damages infrastructure and affects economic stability, particularly in vulnerable communities. Due to geographical and environmental factors, Tsholotsho District in Zimbabwe is highly susceptible to flooding. This study aimed to evaluate the effectiveness of flood response mechanisms for enhancing resilient livelihoods in Tsholotsho and provide actionable insights for policymakers and rural development practitioners. The research used an exploratory sequential mixed methods design, combining qualitative (semi-structured interviews, focus group discussions and document analysis) with quantitative methods (closed-ended questionnaires) This approach gave a understanding of flood response challenges by triangulating findings from various sources. The study focused on flood victims who received aid from organizations, as well as key stakeholders in disaster response, including government departments, NGOs and community leaders. The study specifically targeted wards 6, 7 and 8, in the district which all have a history of severe flooding. Tsholotsho’s vulnerability is heightened by its location on the low-lying Gwayi River, the prevalence of Kalahari and clay soils and the lack of water storage infrastructure. These environmental factors, coupled with climate variability, have resulted in recurrent floods, severely impacting livelihoods. Key findings included significant barriers to effective flood response, such as inadequate financial and technical resources. Government departments struggled to implement proactive measures and an overreliance on donor aid and centralized national funding mechanisms weakened preparedness and delayed recovery efforts. Institutional gaps, including poor coordination among stakeholders and the absence of context-specific disaster management policies, also undermined flood resilience. The study highlighted the need for localized, participatory approaches that integrate both indigenous knowledge and scientific expertise. Key recommendations included the establishment of resilient infrastructure, such as water storage facilities and the enhancement of early warning systems. Strengthening institutional capacity through improved coordination and capacity-building efforts was identified as critical for sustainable flood response. The study emphasized the importance of improving the capacity of local institutions, as government departments often lack the resources and expertise to implement disaster risk reduction strategies effectively. Additionally, better coordination between government, NGOs and communities is essential to ensure that flood response mechanisms are effective and equitable. The research underscored the role of community participation in disaster management. The lack of community involvement in decision-making has led to interventions that do not fully address local needs. Therefore, empowering communities to actively engage in disaster planning, response and recovery is crucial for long-term resilience. Through integrating local knowledge into flood risk management strategies, communities can contribute
valuable insights that enhance disaster response effectiveness. This study challenges top-down disaster management approaches, advocating for inclusive, bottom-up frameworks that empower local communities. The proposed framework stresses the importance of integrated strategies that combine community participation and institutional strengthening. The findings provide valuable insights for flood-prone rural areas globally, offering a roadmap for transforming flood response mechanisms into sustainable development tools. The research contributes to rural development theory by highlighting the intersection of environmental vulnerability, institutional capacity and community participation in disaster resilience, offering a foundation for future research and policy innovation in disaster management
The dilemmas of womanhood and belonging in a Patriarchal Society: A Stiwanist analysis of Selected Radical Female African Novels
No full textM.A. in English LiteratureDepartment of English, Media Studies and LinguisticsThis study thoroughly examined how African women writers reinterpreted and reshaped the concepts of womanhood and belonging in environments influenced by patriarchal beliefs. Based on the theoretical framework of STIWANISM (Social Transformation Including Women in Africa), the study examined two chosen texts: Woman at Point Zero (1983) by Nawal El Saadawi and The Girl with the Louding Voice (2020) by Abi Daré. These novels were analysed using Stiwanism theory and revealed the psychological and socio-economic effects of systemic gender-based oppression. This study showed how patriarchal systems operated to marginalise and silence women through institutions such as society, family, religion, and government, while also enforcing strict gender roles that limited their womanliness. The selected texts highlighted African women's overlapping challenges in their search for identity, purpose, and belonging through the protagonists’ transitions from voicelessness to empowerment. Woman at Point Zero (1983) illustrated a bold rejection of patriarchal authority by refusing to conform, while The Girl with the Louding Voice (2020) exemplified the empowering influence of education and vocal self-expression in defeating patriarchal oppression. The study confirmed that the goals and objectives were effectively achieved. It was determined that educational access, financial autonomy, and regaining voice were vital tools for breaking patriarchal standards and fostering a renewed sense of belonging for African women in their communities and elsewhere
Perceptions and attitudes of adolescents towards contraceptive use at selected village in Thulamela Muicipality in Limpopo Province
No full textMaster of Public HealthDepartment of Public HealthContraceptives are methods endorsed by the World Health Organization to aid in family planning for everyone who is sexually active. While their primary function is to prevent unplanned and unwanted pregnancies. Some contraceptive methods, such as condoms, also play a vital role in preventing sexually transmitted diseases (STIs). Despite the availability of these methods, a significant number of adolescents globally continue to experience unintended pregnancies and STIs, largely due to limited contraceptive use. This study aimed to explore the perception and attitudes of adolescents towards contraceptive use in a selected village within Thulamela municipality, Limpopo Province. A qualitative research approach was employed, using an explorative design. The study population comprised 23 adolescents aged 15 to 19 years. A non-probability sampling method, specifically convenience sampling, was used to select participants. Data were collected through semi-structured interviews, which were audio-recorded and transcribed verbatim. The sample included 23 adolescents, of whom 9 were males and 14 were females. The analysis of the data was conducted using thematic methods. To ensure trustworthiness, the researcher placed a strong emphasis on credibility, confirmability, and authenticity. Ethical considerations were adhered to. The findings revealed that adolescents were generally aware of contraceptives and familiar with different types, of contraceptives, with condoms being the most recognised and commonly used method. However, several barriers to contraception use were identified. These included cultural and religious beliefs, stigma from health professionals, societal pressures, and general fears. The study highlights the urgent need for comprehensive health education on sexual and reproductive health. It also underscores the importance of educating communities to foster more supportive attitude towards adolescent contraceptive use. Furthermore, healthcare providers should enhance the accessibility of adolescent-friendly services including dedicated time slots for adolescents and appointment of youth champions within their facilities, to improve contraceptive uptake among adolescents
Thodisiso nga ha tshivhangi tsha pfudzungule dzo disendekaho nga luambo mitani ya vharema mbinganoni
No full textPhD (African Languages)Department of African LanguagesNdivho ya ṱhoḓisiso ino ndi u ṱoḓisisa nga tshivhangi tsha pfudzungule dzo ḓisendekaho nga luambo miṱani ya vharema mbinganoni ho sedzwa Vhavenḓa. Ṱhoḓisiso ino yo sedzesa pfudzungule dza miṱani dzo ḓisendekaho nga luambo sa tshone tshivhangi tshihulwane tsha thaidzo kha lushaka musalauno. Kha vhana na vhafumakadzi hu khou vhonala vha vhone vhane vha khou kwamea vhukuma nga pfudzungule dza miṱani. Miṱa i khou pwashekana na miṅwe miraḓo ya miṱa i khou xelelwa nga vhutshilo nga thaidzo iyi. Pfudzungule dza miṱani dzi itea nga nḓila dzo fhambanaho, hu nga vha nga luambo kana nga u vhaiswa kha muvhili. Ṱhoḓisiso yo itwa kha Tshiṱiriki tsha Vhembe vunduni ḽa Limpopo. Khonadzeo ya u sa nangwa ya ndivho (purposive) na sambula nga u laedzwa (snowball) zwo shumiswa kha u dzhia tsheo ya vhavhudziswa kha ṱhoḓisiso ino. Sambula ya khonadzeo ya ndivho ya u sa nanga yo shumiswa ho sedzeswa vhathu vhane vha khou kwamea tshoṱhe nga thaidzo iyi. Sambula yo shumiswa musi muṱoḓisisi a tshi khou ṱoḓa vhathu vho kwameaho nga pfudzungule dza miṱani. Ho shumiswa muelo wa sambula wo linganelaho. Ngona ya khwaḽithethivi yo shumiswa na ngona ya khwanthithethivi fhedzi ho shumesa vhukuma ngona ya khwaḽithethivi. Ho sedzwa na tshenzhemo ya vhathu vhenevho vho dzhenelelaho kha ṱhoḓisiso. Thyiori ya “Afrocentric” yo shumiswa kha ṱhoḓisiso ino vhunga i tshi ṱuṱuwedza uri musi muthu a sa athu dzhia ḽiga ḽa u bula ipfi u fanela u thoma a humbula zwine a tea u amba. Thyiori ya Afrocentric i katela kuhumbulele, nyito, lutamo na mvelele. Data yo kuvhanganywa nga nḓila dza mbudzisavhathu dza u tou ṅwalwa zwi tshi bva kha mbudzisavhathu u wana mafhungo nga ha pfudzungule dzi vhangwaho nga luambo miṱani. Muṱoḓisisi o khethekanya data yawe u ya nga thero, nga murahu ha konwa u senguluswa data. Kha tsenguluso ya data ho shumiswa nḓila dza u khouda. Dzenedzo ndi u khouda hu re khagala “open coding”, u khouda ha mbuedzo “axial coding” na u khouda ha u nanguludza” selective coding” fhedzi. Musi ṱhoḓisiso yo no fhela ho wanala mawanwa na themendelo zwi bvaho kha data yo kuvhanganywaho. Ri tshi lavhelesa mawanwa, hu khou vhonala uri hu na mbilaelo nnzhi dzine dza sa khou tshimbila zwavhuḓi miṱani vhukati ha munna na mufumakadzi zwi tshi katela na mashaka zwi tshi kwama luambo. Mbilaelo idzo arali dza nga sedzuluswa zwavhuḓi zwi nga thusa vhukuma kha u khwinifhadza nzulele dza miṱani mbinganoni kha Vhavenḓa uri hu dzulwe nga mulalo.National Research Foundation (NRF
An exploration of the use of social media as a vehicle to enculturate Vhavenda youth in the Vhembe District, Limpopo Province of South Africa
No full textPhD (African Studies)This qualitative study explored the use of social media as a vehicle to enculturate Vhavenḓa youth in the Vhembe District of Limpopo Province, South Africa. The study examined the possibility of using social media platforms to enculturate youth with the indigenous knowledge system (IKS). IKS mainly relies on information being passed on by word-of-mouth from adults; hence, it requires direct interactions between the older and younger generations. Social media have taken over the socialisation role played by older adults; however, how social media can be used to enculturate the youth is unclear due to the nature and beliefs associated with IKS. The major issues at the heart of this study are how people perceive the function of social media in enculturating youth with indigenous knowledge system content and what strategies can be employed to integrate IKS with social media. In-depth unstructured interviews and focus-group discussions were used to collect data from 25 youth and 25 elderly indigenous knowledge holders from 11 local communities from the Vhembe District Municipality.
Using a Thematic Content Analysis (TCA) to examine the collected qualitative data, the study concluded that to present to the present generation what speaks to their identity and way of being, various social media platforms need to be fed with content that discusses cultural programs, practices, values, and standards. The study’s key conclusions were that social media sites like Facebook, Twitter, Instagram, YouTube, WhatsApp and many more could be utilized to ingrain IKS. This process can be facilitated if the government provides financial resources to familiarise communities with IK. The study advised that various media outlets should develop programs that broadcast IKS content using indigenous languages to enculturate the current and upcoming generations. This was made possible by adopting the theory of socialisation as the study sought to find ways in which social media could be utilised to enculturate Vhavenda youth. The study found that social media platforms such as WhatsApp, Facebook, Instagram, Internet, and YouTube are the main vehicles for enculturating youth.National Research Foundation (NRF
Computational study of selected antimalarial and anticancer acylphloroglucinols
No full textPhD (Chemistry)Department of ChemistryMalaria and cancer tend to become drug-resistant few years after a drug is introduced into clinical use. This prompts the search for new molecular structures that are sufficiently different from the drugs for which resistance has developed. Acylphloroglucinols (ACPLs) are natural compounds with several biological activities. They are considered as possible lead structures for developing drugs against degenerative and other diseases. Computational studies are particularly important for biologically active compounds because their activities depend on their molecular properties, and knowing these properties (descriptors) is necessary for drug development.
Representative ACPLs with anticancer and/or antimalarial activities were selected and computationally studied in vacuo and in three solvents with different polarities. All the calculations were done with completely relaxed geometry, using the Hartree Fock (HF) and Density Functional Theory (DFT) methods; second-order Moller-Plesset perturbation theory (MP2) calculations were also performed in vacuo. Structure-based virtual screening was used to study the interactions between these molecules and relevant proteins. The conformational studies identified conformational preferences and conformers’ stabilizing factors, among which intramolecular hydrogen bonds (IHBs) have dominant roles. The highest-occupied molecular orbital (HOMO) - lowest-unoccupied molecular orbital (LUMO) energy gap decreases and the dipole moment increases as the medium polarity increases. The solvent effect depends on the conformer type and the solvent polarity. The molecular docking analysis shows that most of these compounds bind well with the selected proteins and highlights the type of molecule-protein interactions for each case. These results indicate that the selected molecules are interesting for further steps in view of their possible development into antimalarial and anticancer drugs.National Research Foundation (DST-NRF) Innovation Doctoral Scholarship and the S and F- Sasol Inzalo Foundatio
Characterization and potential for the genetic improvement of pigeonpea (cajanus cajan ) landraces
No full textPhD (Agronomy and Crop Sciences)Department of Plant and Soil SciencesPigeonpea (Cajanus cajan) is an important grain legume that provides highly nutritious food for human consumption, livestock feeds and fixes considerable amounts of atmospheric nitrogen, thus improving soil fertility. Local farmers utilize traditional unimproved cultivars that are inherently low yielding limiting the adoption of the crop. The narrow genetic base of pigeonpea limits plant breeding efforts aimed at improving the species. Determining the genotypic variation in agronomic and nutritional attributes among pigeonpea genotypes is essential for improving crop productivity and nutritional content of the crop. Nonetheless, there is a dearth of information regarding the characterization and the genetic diversity in agronomic and nutritive attributes in the pigeonpea germplasm pool maintained at the University of Venda. Therefore, the aim of this study was to characterize and evaluate the potential for the genetic improvement of the agronomic and nutritive attributes of pigeonpea landraces. The specific objectives of the study were to: (i) determine the genetic diversity in agro-morphological attributes (ii) determine the genetic diversity in selected nutritive attributes among pigeonpea landraces (iii) characterize the seed storage proteins in pigeonpea landraces and (iv) determine the general and specific combining abilities for agronomic attributes among pigeonpea landraces.
For the first objective of the study, the genetic variation for agronomic and morphological traits among fourteen pigeonpea landraces from the germplasm pool maintained at the University of Venda was evaluated. The genotypes were raised in pots filled with top (up to 25.0 cm deep) soil from the field in the shadehouse for two consecutive seasons. In each season, the experiment was laid out in a completely randomized design replicated three times. Qualitative traits such as the branching pattern, stem colour, flower colour, pod colour and testa colour were recorded. The quantitative traits that were recorded included plant height at flowering (PHF), number of primary branches (NPB), number of secondary branches (NSB), number of seeds per pod (NSP), number of pods per plant (NPP), pod length (PL), hundred seed weight (100-SW) and grain yield per plant (GYPP). The Shannon Weaver diversity index (H’) revealed that the testa colour (1.254) and seed colour pattern (1.301) were the most divergent qualitative traits. There were marked differences in the duration to flowering ranging from 84.67 to 132.83 days with a mean of 117.05 days. The genotype ‘T1’ required 16.0 g per 100 seeds). The grain yield per plant varied between 19.9 – 51.7 g. The best performing genotypes (with mean GYPP > 45.0 g) were ‘L1’ and ‘L5’. The principal component analysis (PCA) revealed that the first two principal components with eigenvalues of more than one accounted for 58.04% of the variation among the pigeonpea genotypes. Positive correlations observed between most
secondary traits showed that multiple trait selection is possible. The NPP, 100-SW and GYPP were the most important agronomic attributes for assessing genetic variation due to their high contribution to the variation accounted on PC1 and PC2. The findings revealed the potential for exploiting genetic diversity to improve pigeonpea agronomic performance.
The second study objective focussed on determining the diversity in nutritional attributes among pigeonpea landraces. Seed samples (5.0 g each) from each of the genotypes harvested from the study of the first objective were harvested and processed for determining mineral composition using the Inductively Coupled Plasma Emission Spectrometer. Relatively high amounts of calcium (2103.43 mg/kg) and manganese (73.11 mg/kg) were observed in ‘L3’. High amounts of zinc (38.56 mg/kg) were observed for ‘L9’ whereas ‘L4’ produced high levels of phosphorus (4945.12 mg/kg). The PCA showed that the first two principal components cumulatively explained 62.06% of the total variation among the pigeonpea genotypes. On the PCA biplot, Ca, Mg, Mn and P were associated with ‘L3’, ‘L4’ and ‘L5’ respectively. Genotypes producing high crude protein and high mineral concentrations in most nutritional traits (i.e., ‘L1’, ‘L3’, ‘T1’ and ‘T4) could be used as parental lines for the genetic improvement of nutritional attributes in pigeonpea. The variability in the range of mineral elements among pigeonpea genotypes indicated that there was genetic potential for selection of parental lines for nutritional quality improvement of the crop.
The third study objective was designed to characterize the seed storage proteins of pigeonpea using initially the sodium dodecyl sulphate polyacrylamide gel electrophoresis (SDS PAGE) in a 12.0% separating gel in a discontinuous buffer system. The SDS PAGE resolved the pigeonpea seed storage proteins into 21 protein bands with molecular weights ranging from 10 to 250 kDa. The absence of the 42, 58, 130 and 250 kDa subunits in genotype ‘L2’ and the presence of the 58 kDa in genotype ‘T5’ could be used for genotypic identification. Thereafter, gel fractions were excised and prepared for the Liquid Chromatography – Mass Spectrometry analysis (LCMS) to evaluate the proteomic variation in seed and determine their functional spectrum. The spectroscopic analysis identified 446 proteins from pigeonpea seed constituted mainly by stress related proteins such as heat shock protein, proteases and chaperones amongst others. Proteases were localized in the nucleus, cytoplasm, proteasome regulatory particle and complex. The amino acid sequence alignment revealed functional motifs such as the Walker A, Walker B and the DEVD. The MPN (Mpr1, Pad1 N-terminal), PCI (Proteasome, COP9, Initiation factor 3) and AAA+ ATPase were the protein superfamilies recognized from the proteases. There was 97.31% similarity between the 26S proteasome regulatory subunit 4 homolog A (A0A1S2XSJ5) and the 26S proteasome regulatory subunit 4 homolog A-like (A0A1S2XWG8) when the amino acid residues were aligned with each other. The proteomic analysis identified large number of stress related proteins probably due to pigeonpea’s ability
to withstand harsh environmental conditions such as drought, salinity and extreme temperatures.
The final study objective estimated the general and specific combining ability effects as well as the gene action controlling agronomic traits in pigeonpea at the vegetative stage. Nine progenies derived from three lines and three testers in a line x tester mating design were evaluated for agronomic traits at the vegetative growth stage together with their parents in the shadehouse. Crosses were carried out manually by emasculation using forceps prior to flower opening. Each cross was labelled for subsequent identification. The six parents and their nine F1 progenies were raised simultaneously in the shadehouse in pots (as described above). Agronomic traits such as the PH, NPB, and the branching angle (BA) were recorded. The experiment was laid as a completely randomized design with three replications. Line ‘L3’ was the best general combiner for the NPB and BA exhibiting desirable positive GCA effects of 4.00 and 5.37 in the desirable direction. The tester ‘T4’ had positive and significant GCA effects of 11.815 for PH. The crosses ‘L3xT5’, ‘L4xT2’, ‘L5xT4’ and ‘L5xT5’ were good specific combiners for PH with significant and positive SCA estimates of 13.730, 48.396, 25.352 and 15.185, respectively. The best specific combiners for NPB were ‘L4xT2’ (4.778) and ‘L5xT5’ (5.556). For canopy width, the cross ‘L4xT2’ produced a SCA value of 16.363 followed by ‘L5xT5’ with 15.196 in a desirable direction. The narrow sense heritability for all the traits was low (<12.0%) indicating that there is a predominant role of non-additive gene actions for the traits evaluated in this stud