School of Molecular & Cell Biology (ETDs)

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Browsing School of Molecular & Cell Biology (ETDs) by SDG "SDG-15: Life on land"

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    Isolation and characterisation of entomopathogenic fungi
    (University of the Witwatersrand, Johannesburg, 2024) Kwinda, Fhatani; Lephoto, Tiisetso E.
    The purpose of the study was to isolate and identify fungal isolates in soil samples, followed by virulence characterisation to study their effectiveness in controlling insect pests using Tenebrio molitor as our model organism. Lastly, a combination study was conducted to evaluate the effectiveness of the joint use of two entomopathogenic microorganisms. For isolation, T. molitor was used as bait then the isolated fungal isolates were identified using molecular and morphological characterisation. Morphological characterisation included macroscopic (fungal cultures) and microscopic (conidia shape and size) analysis while molecular characterisations included extraction of DNA, amplification of the internal transcribed spacer region and sequence alignment. Once identification was done, virulence was assessed through in-vitro virulence parameter like vegetative growth and in-vivo assessment where bioassays were done against T. molitor. Lastly, entomopathogenic fungi were combined with Cruznema sp. NTM-2021 in a soil assay. From the study, two of the five isolates were identified as entomopathogenic fungi, Metarhizium anisopliae ARSEF 7487. M. anisopliae had the slowest vegetative growth but was the highest in virulence. When used for a single application in a soil environment it reaches 97.8% mortality and its combination with Cruznema sp. NTM-2021 resulted in a 57.8% mortality and an additive interaction. In conclusion, M. anisopliae used alone was effective in its control of T. molitor
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    Moving towards landscape initiatives: an analysis of environmental frameworks, protected areas, and community perspectives in the vhembe district, limpopo province, South Africa
    (University of the Witwatersrand, Johannesburg, 2024) Dalziel, Alexandra; Evans, Mary
    ConservaBon strategies have shiMed towards a landscape-centric approach, emphasising conservaBon corridors and ecological networks. However, exploraBon of these strategies within the South African context is incomplete. This research aims to address this gap by applying various methods, including a systemaBc literature review, policy analysis, spaBal analysis using GIS, and conducBng interviews and surveys, resulBng in four key contribuBons invesBgaBng the potenBal for conservaBon corridors and networks. The first is a comprehensive literature review underscoring the significance of corridors and networks while highlighBng the discourse surrounding these emerging approaches in South Africa. The findings revealed a substanBal global interest in landscape iniBaBves. However, South Africa’s contribuBon is geographically limited, with 82% of studies focusing on the KwaZulu-Natal province. Understanding the efficacy of these studies in South Africa necessitates a comprehensive examinaBon of the underlying regulatory frameworks governing protected areas and conservaBon efforts. Therefore, the second contribuBon evaluated protected areas and conservaBon legislaBon and policies to assess their alignment with landscape-focused iniBaBves. The study reveals a lack of explicit provisions supporBng landscape-based conservaBon methods. The third study draws on these findings and uses the Vhembe District in the Limpopo Province as a case study to illustrate the overlooked potenBal of landscape iniBaBves. IniBally, the protected areas in the district were evaluated. Subsequently, the analysis employed Key and CriBcal Biodiversity Areas to highlight the inadequacies within the exisBng protected area network. The findings revealed that although protected areas cover 38% of the Vhembe District, over 70% of CriBcal Biodiversity Areas and 60% of Key Biodiversity Areas lack protecBon. Over 2,000 km2 of unprotected CriBcal and Key Biodiversity Areas were idenBfied along the Soutpansberg Mountain Range and marked as ideal for a conservaBon corridor. The fourth contribuBon centres on community engagement, an essenBal consideraBon for sustainable long-term conservaBon. The results underscored strong community support for a corridor in the Vhembe District, primarily moBvated by the anBcipated socio-economic benefits. However, while landscape iniBaBves promise socio-economic improvement, such outcomes are not guaranteed. Moreover, other potenBal challenges, including development, land rights, and financial constraints, were idenBfied as possible impediments to corridors in the Vhembe District. The invesBgaBon into corridors and networks in South Africa, specifically the Vhembe District, revealed that the discourse on landscape iniBaBves is in its nascent phase. Nevertheless, when prioriBsing community engagement, these iniBaBves harbour tremendous potenBal. New legislaBon and policies that account for these factors will guide proponents of these iniBaBves and propel landscape iniBaBves into South Africa’s conservaBon toolbox.
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    The genome sequence of the Yellow-billed Duck (Anas undulata)
    (University of the Witwatersrand, Johannesburg, 2024-01) Ngxamani, Namhla; De Maayer, Pieter; Mollett, Jean
    No abstract given