Characterisation of Taro (Colocasia Esculenta (L) Scott) germplasm collections in South Africa : towards breeding an orphan crop.

Doctor of Philosophy in Plant Breeding. University of KwaZulu-Natal, Pietermaritzburg, 2017.Amadumbe (Colocasia esculenta), better known as taro, is a traditional root crop widely cultivated in the coastal areas of South Africa. Taro is showing potential for commercialisation. However, very little is known about the genetic diversity, potential and its introduction and movement in South Africa. This study was undertaken to (1) determine the genetic diversity in the ARC taro germplasm collection using agromorphological characteristics and microsatellite markers, (2) to determine if it is possible to breed with local taro germplasm and (3) to determine the effect of four different environments (Roodeplaat, Umbumbulu, Owen Sithole College of Agriculture and Nelspruit) on ten agro-morphological characteristics of 29 taro landraces Taro germplasm was collected in South Africa in order to build up a representative collection. Germplasm was also imported from Nigeria and Vanuatu. The South African taro germplasm, and selected introduced germplasm, were characterised using agromorphological descriptors and simple sequence repeat (SSR) markers. Limited variation was observed between the South African accessions when agro-morphological descriptors were used. Non-significant variations were observed for eight of the 30 agromorphological characteristics. The 86 accessions were grouped into three clusters each containing 39, 20 and 27 accessions, respectively. The tested SSR primers revealed polymorphisms for the South African germplasm collections. Primer Uq 84 was highly polymorphic. The SSR markers grouped the accessions into five clusters with 33, 6, 5, 41 and 7 accessions in each of the clusters. All the dasheen type taro accessions were clustered together. When grown under uniform conditions, a higher level of genetic diversity in the South African germplasm was observed when molecular (SSR) analysis was performed than with morphological characterisation. No correlation was detected between the different clusters and geographic distribution, since accessions from the same locality did not always cluster together. Conversely, accessions collected at different sites were grouped together. There was also no clear correlation between the clustering pattern based on agro-morphology and SSRs. Thus, in order to obtain a more complete characterisation, both molecular and morphological data should be used. Although the results indicated that there is more diversity present in the local germplasm than expected, the genetic base is still rather narrow, as reported in other African countries. Fourteen distinct taro genotypes were planted as breeding parents and grown in a glasshouse. Flowering were induced with gibberellic acid (GA3). Crosses were performed in various combinations; however, no offspring were obtained. This might be due to the triploid nature of the South African germplasm. It might be useful to pollinate diploid female parents with triploid male parents or use advanced breeding techniques, like embryo rescue or polyploidization, to obtain offspring with the South African triploid germplasm as one parent. The triploid male parents might produce balanced gametes at low percentages, which can fertilize the diploid female parents. Twenty-nine taro accessions were planted at three localities, representing different agroecological zones. These localities were Umbumbulu (South of Durban - KZN), Owen Sithole College of Agricultural (OSCA, Empangeni, KZN) and ARC - Vegetable and Ornamental Plants (Roodeplaat, Pretoria). Different growth and yield related parameters were measured. The data were subjected to analysis of variance (ANOVA) and additive main effects and multiplicative interaction (AMMI) analyses. Significant GxE was observed between locality and specific lines for mean leaf length, leaf width, leaf number, plant height, number of suckers per plant, number of cormels harvested per plant, total weight of the cormels harvested per plant and corm length. No significant interaction between the genotype and the environment was observed for the canopy diameter and corm breadth. From the AMMI model, it is clear that all the interactions are significant for leaf length, leaf width, number of leaves on a single plant, plant height, number of suckers, number of cormels harvested from a single plant and weight of cormels harvested from a single plant. The AMMI model indicated that the main effects were significant but not the interactions for canopy diameter. The AMMI model for the length and width of the corms showed that the effect of environment was highly significant. There is a strong positive correlation between the number of suckers and the number of leaves (0.908), number of cormels (0.809) and canopy diameter (0.863) as well as between the number of leaves and the canopy diameter (0.939) and between leaf width and plant height (0.816). There is not a single genotype that can be identified as “the best” genotype. This is due to the interaction between the environments and the genotypes. Amzam174 and Thandizwe43 seem to be genotypes that are often regarded as being in the top four. For the farmer, the total weight of the cormels harvested from a plant will be the most important. Thandizwe43, Mabhida and Amzam174 seem to be some of the better genotypes for the total weight and number of cormels harvested from a single plant and can be promoted under South African taro producers. The local accessions also perform better than introduced accessions. It is clear that some of the introduced accessions do have the potential to be commercialised in South Africa. The study indicate that there are genetic diversity that can be tapped into for breeding of taro in South Africa. However, hand pollination techniques should be optimized. Superior genotypes within each cluster in the dendrograms as well as Thandizwe43, Mabhida and Amzam174 (identified by the AMMI analysis as high yielding) can be identified and used as parents in a clonal selection and breeding programme. Additionally, more diploid germplasm can be imported to widen the genetic base. The choice of germplasm must be done with caution to obtain germplasm adapted to South African climate and for acceptable for the South African consumers

The projection of religion onto politics : mechanisms and patterns

Religious Studies and ArabicM.A. (Religious Studies

Strategies for fostering critical thinking dispositions in the technology classroom

Critical Thinking (CT) consists of two components, namely, skills and dispositions. Although there is a fair amount of literature focusing on CT and the development of CT skills, the literature on CT dispositions and, in particular, strategies to promote the dispositional component of CT is lacking. This means that there is insufficient literature available to guide teachers in their practice regarding the ways in which they could foster CT dispositions. This is particularly problematic for technology teachers as they may not be fully informed on how to use the opportunities offered by the design process, as prescribed by the South African Department of Basic Education. This study thus aimed to investigate and describe how technology teachers use the opportunities presented by the design process to foster CT dispositions. This study engaged in a qualitative research approach and a case study design. Ten purposefully sampled teachers were interviewed, 5 of whom were observed for one design-based lesson. As reported by (Facione in Critical thinking: What it is and why it counts, The California Academic Press, Millbrae, 2011) 7 Dispositions toward CT were used to guide the inquiry. The analysis of the data indicated that the participants used 4 main strategies that acted as a platform for, or led to the use of another 4 supporting strategies. The 4 main strategies are: assessments, questioning, examples, and the classroom environment. The 4 supporting strategies are: discussions, modelling, feedback, and resources. The results and conclusions of this study are not considered as the final answer to the lack of literature, but they provide a starting point for further investigation and development.https://link.springer.com/journal/10798hj2023Science, Mathematics and Technology Educatio

Detection of human papillomavirus DNA with in situ hybridisation in oral squamous carcinoma in a rural black population

No Abstract

Godsdiens en die reg : herwaardering van die Hervormde Kerk se Besluit 41 (2016) oor homoseksualiteit1

In 2016, the General Assembly of the Nederduitsch Hervormde Kerk van Afrika (Netherdutch Reformed Church of Africa, or NHKA) passed a resolution on homosexuality. In one section, Resolution 42 (2016) it is claimed that “Jesus Christ, through the Spirit, helps people to live in the presence of God as complete human beings, including their sexuality. This is also true of people with a homosexual orientation. Therefore, the Church believes that all Christians, irrespective of their sexual orientation, are members of the body of Christ with full participation in the sacraments. This is an expression of the unity of the Church.” Unlike the extreme discomfort with similar resolutions expressed within and by other churches, the resolution elicited relatively little resistance from church members in the NHK, and to date there has been no legal consequences with respect to the decision. In this article we will discuss Resolution 41 (2016) in terms of the governing principles of reformed church polity, with some remarks on its legal implications. In the presbyterial-synodal (reformed) system of church government, there are guiding principles which must be considered when a synod reflects on a particular matter. First and foremost, the principle that Christ governs the church through his Word and Spirit determines all aspects of church governance. The contents of resolutions are determined by five principles (in order of importance), i.e. the Word of God, confessions and creeds, church order, previous resolutions of assemblies, and customs or practices of the church. Resolution 41 (2016) will be assessed with reference to each of the above principles. Each of these guiding principles is discussed by engaging in dialogue with Resolution 41 (2016), to determine how and if it conforms to the guiding principles of reformed church polity. The discussion also includes some remarks on church polity and church governance as an ius sui generis, which is different from civil law. The unique character of church polity is explained in terms of the presbyterial-synodal form of church governance, typical of reformed churches all over the world. In the reformed tradition, the Word of God entertains a central position as the authority and norm for Christian doctrine and life (sola Scriptura). It is pointed out that the Word of God as guiding principle is neither self-evident nor unproblematic, due to different views of what constitutes the Word of God as well as diverse hermeneutic approaches to the Bible text. It is also argued that a sixth guiding principle should be considered, i.e. administrative justice. Although ecclesiastical law is an ius sui generis, it does not exclude the general principles of justice, fairness, equity, etcetera. Quite the opposite. It is the church’s Christian duty and responsibility to ensure that all decisions are taken in a spirit of fairness, with consideration of due process. The integrity of the ecclesiastical process and procedure should be of the highest ethical standard. In such an approach, synod resolutions, while heeding the Word of God, simultaneously take into consideration the Bill of Human Rights and the Constitution of South Africa. Resolution 41 (2016) represents something of a “third way” in terms of ecclesiastical decisions on homosexuality, avoiding hard or extreme points of view. This reconciliatory nature of the resolution is probably the reason why it was met with little opposition from church members. Even the media and members of the public responded positively to the resolution.Een van die ingrypende, traumatiese en emosiebelaaide kwessies waaroor kerke in die laaste twee dekades besluite geneem het, is homoseksualiteit en die toelating van gay mense tot die amp van predikant. Hierdie bydrae handel oor Besluit 41 (2016) wat die Algemene Kerkvergadering van die Nederduitsch Hervormde Kerk van Afrika (Hervormde Kerk) oor homoseksualiteit geneem het. Besluit 41 (2016) word terugskouend, op grond van tersaaklike kerkregtelike beginsels, beoordeel en herwaardeer, met enkele opmerkinge oor die regsimplikasies daarvan. Tradisioneel moet kerkvergaderings die Bybel, belydenisskrifte, kerkorde, besluite van vorige vergaderings en usansie in gedagte hou wanneer daar oor ’n saak besin en besluit word. In hierdie bydrae word geredeneer dat die beginsel van administratiewe geregtigheid ook ter sake is, nie net uit vrees dat howe ’n kerklike besluit ter syde kan stel nie, maar omdat dit ’n inherente deel van die Christelike kerk is om mense met liefde en billikheid te behandel. Daarbenewens is die plek en die funksie van die kerkorde as onderlinge kontrak ter sake. Dit beteken dat ook die kontraktereg ter sprake kom wanneer die hof kerklike besluite hersien. So voldoen kerklike besluite nie net aan die eise van die Woord nie, maar ook indirek aan die bedoeling van die Grondwet van Suid-Afrika.Hierdie artikel vorm deel van die vereistes vir die graad PhD (Kerkgeskiedenis en Kerkreg) aan die Fakulteit Teologie en Religie, Universiteit van Pretoria.https://journals.co.za/content/journal/akgeeshj2021Church History and Church Polic

Oorsprong van die drievoudige struktuur van die Heidelbergse Kategismus

The Heidelberg Catechism was one of many catechisms that originated during the 16th-century Reformation. It is also known that the authors of the Heidelberg Catechism made use of existing catechisms. The content of 16th-century catechisms consisted mainly of the Decalogue, the Apostolicum and the Lord’s Prayer. The Heidelberg Catechism starts with the famous introduction, dealing with man’s only comfort, and in three sections with knowledge of our sin and misery, knowledge of our deliverance, and knowledge of how we should be grateful for our deliverance. This contribution points out that the threefold structure of the Heidelberg Catechism is not unique, but appeared in different ways in different catechisms of prominent 16th-century reformers. It is also argued that the Heidelberg Catechism should be read against Lutheran and Calvinistic backgrounds. Finally, it is shown that the Heidelberg Catechism articulated the basic Christian faith in such a beautiful and poignant manner that it stood the test of time as a catechism and confession.This research is part of the research project, ‘Ecumenical creeds and Confessions’, directed by Dr Wim Dreyer, Department of Church History and Church Polity, Faculty of Theology, University of Pretoria.This article is based on research done by A. Janse van Rensburg for the completion of the degree Magister Theologiae, under supervision of Dr W.A. Dreyer, Department of Church History and Church Polity, Faculty of Theology, University of Pretoria. The support of the University of Pretoria and the Johannes a Lasco Institute (Emden, Germany), is hereby acknowledged with gratitude.http://www.hts.org.zaam2016Church History and Church Polic

Conservation of African Leafy Vegetables in South Africa

The nutritional and cultural importance of African Leafy Vegetables has become very important in South Africa in the past few years. Recent research has also confirmed these issues, leading to the incorporation of African Vegetables into the core business of the ARC. ARC-Roodeplaat wants to improve the distribution and conservation status of African Leafy Vegetables. Geographical collection data on Amarant, Cleome gynandra, Corchorus olitorius and Vigna inguiculata was obtained from the National Botanical Institute and the data was analyzed with DIVA and Flora map. Ecogeographical distribution maps were drawn to predict the possible distribution of the species. Germplasm of African Leafy Vegetables was collected during routine visits and the conservation status was discussed with participants in the study areas of Arthurstone in Bushbuckridge, Watershed near Ladysmith and Mars/Glenroy near Polokwane. Germplasm of various species were also collected in collaboration with the Plant Genetic Resource Centre (NPGRC) of the Department of Agriculture in Arthurstone and Watershed.The NPGRC included leafy vegetables in their mandate since this trip. Seed flow diagrams were used to discuss the Watershed community’s seed exchange systems. It was clear when discussing African leafy vegetables in communities that their conservation and utilization are declining. Also looking at the trendlines of African Vegetables availability and utilization it is clear that the use and availability of African Leafy vegetables are declining due to various reasons. Two major reasons are the negative image of the African Leafy Vegetables and the increased use of “exotic” vegetables like spinach and carrots. The active promotion, use and conservation of African Leafy Vegetables are important if we want to increase the production potential and potential contribution towards food security in South Africa. This will ensure that the status of these crops is enhanced, specifically their contributing towards sustainable nutrition as well as sustainable production. Results from promotion activities in the project (reported in another paper) indicated that the negative image of African Leafy Vegetables could be reversed and also had an affect on the roll-out of the project to other areas of research such as plant protection, nutritional analysis and food safety, crop science and indigenous knowledge systems.Key Words: Ecogeographical, Conservation, Leafy vegetable  

Effects of different penning conditions, feeding regimens and season on growth and carcass attributes of boars of a selected genetic line

The study tested the performance of intact male pigs from a selected genetic line subjected to differing feeding regimens and penning conditions. The trial was a 2 x 3 x 2 x 3 factorial design, consisting of winter and summer periods, three sire lines, two diets and three feeding regimens. The pigs were intact males grown over three phases, starter (25 to 50 kg); grower (51 to 80 kg) and finisher (81 to 105 kg).The pigs were randomly allocated to three feeding regimens, a controlled single feeding, ad libitum single feeding and ad libitum group feeding, with six animals per ad libitum group. This resulted in 96 pigs in six treatments with six replicates. The diets were high (HF) and low (LF) nutrient dense feeds, where the LF was 95% of the HF. Season affected growth; the winter animals had a significantly greater growth response, end-mass and average daily gain (ADG). The HF diet resulted in significant improved ADG, feed conversion ratio and protein deposition rate, especially during summer. However, end-mass, ADG and average protein deposition rates of controlled-fed pigs were significantly lower compared to the ad libitum group and single-fed animals. The hypothesis was affirmed that high-performing intact male pigs are sensitive to and affected by feeding regimens and penning conditions that will affect their production.http://www.sasas.co.za/nf201

Effect of modified atmosphere packaging on the quality and bioactive compounds of Chinese cabbage (Brasicca rapa L. ssp. chinensis)

BACKGROUND : The perishability of Brassica chinensis poses a major challenge to distribution and marketing. The aim of this work was to select a suitable modified atmosphere packaging to retain the overall quality and bioactive compounds during storage. RESULTS : Four types of biorientated polypropylene packaging (BOPP) – BOPP03, BOPP04, BOPP05 and BOPP06 – with different perforations were evaluated regarding the maintenance of quality parameters (weight loss, leaf yellowing, colour L*, C*, h°), decay, chlorophyll a, chlorophyll b, bioactive compounds (carotenoids, ascorbic acid, total phenolic compounds), antioxidant scavenging activity, overall appearance and odour evaluation, at 10°C at 2, 4, 6, 8 and 10 days. Leaves were packed in BOPP (two 2-mm holes) and packed and unpacked leaves were included for comparison. The modified atmosphere created (2% O2 and 7% CO2) inside the BOPP05 reduced leaf yellowing (higher h°), improved the overall appearance with acceptable odour, moderately maintained chlorophyll a and b, bioactive compounds and antioxidant scavenging activity, and remained marketable for up to 10 days at 10°C. Gas composition within the packages influenced the retention of bioactive compounds and overall quality. CONCLUSION : Application of BOPP05 is a promising method for extending the shelf life of B. chinensis leaves in order to promote its utilisation and commercialisation via urban fresh-produce markets.The National Research Foundation (NRF), South Africa as well as the postgraduate bursary award from the Tshwane University of Technology Research & Innovation Directorate, Pretoria, South Africa, to Ms Bevly Mmakatane Mampholo.http://onlinelibrary.wiley.com/journal/10.1002/(ISSN)1097-0010hb2016Biochemistr