scholarly journals Elusive Diagnostic Markers for Russian Wheat Aphid Resistance in Bread Wheat: Deliberating and Reviewing the Status Quo

2020 ◽  
Vol 21 (21) ◽  
pp. 8271
Author(s):  
Vicki L. Tolmay ◽  
Scott L. Sydenham ◽  
Thandeka N. Sikhakhane ◽  
Bongiwe N. Nhlapho ◽  
Toi J. Tsilo
Keyword(s):  
South African ◽  
Resistance Breeding ◽  
Triticum Aestivum L ◽  
Russian Wheat Aphid ◽  
Diagnostic Markers ◽  
Aphid Resistance ◽  
Resistance Response ◽  
The Status ◽  
Complex Regulation ◽  
Coherent Body

Russian wheat aphid, Diuraphis noxia (Kurdjumov), is a severe pest of wheat, Triticum aestivum L., throughout the world. Resistant cultivars are viewed as the most economical and environmentally viable control available. Studies to identify molecular markers to facilitate resistance breeding started in the 1990s, and still continue. This paper reviews and discusses the literature pertaining to the D. noxia R-genes on chromosome 7D, and markers reported to be associated with them. Individual plants with known phenotypes from a panel of South African wheat accessions are used as examples. Despite significant inputs from various research groups over many years, diagnostic markers for resistance to D. noxia remain elusive. Factors that may have impeded critical investigation, thus blurring the accumulation of a coherent body of information applicable to Dn resistance, are discussed. This review calls for a more fastidious approach to the interpretation of results, especially considering the growing evidence pointing to the complex regulation of aphid resistance response pathways in plants. Appropriate reflection on prior studies, together with emerging knowledge regarding the complexity and specificity of the D. noxia–wheat resistance interaction, should enable scientists to address the challenges of protecting wheat against this pest in future.

Genetic mapping of Russian wheat aphid resistance genes Dn2 and Dn4 in wheat

Genome ◽  
1998 ◽  
Vol 41 (2) ◽  
pp. 303-306 ◽  
Author(s):  
Z -Q Ma ◽  
A Saidi ◽  
J S Quick ◽  
NLV Lapitan
Keyword(s):  
Triticum Aestivum ◽  
Restriction Fragment Length Polymorphism ◽  
Resistance Genes ◽  
Fragment Length Polymorphism ◽  
Triticum Aestivum L ◽  
Russian Wheat Aphid ◽  
Aphid Resistance ◽  
Rflp Markers ◽  
Marker Assisted Breeding ◽  
Restriction Fragment Length

To obtain markers for marker-assisted breeding of Russian wheat aphid resistance in wheat (Triticum aestivum L.), resistance genes Dn2 and Dn4 were mapped with restriction fragment length polymorphism (RFLP) markers, using populations derived from PI 62660 x 'Carson' and PI 372129 x 'Yuma'. PI 262660 and PI 372129 are the donor parents of Dn2 and Dn4, respectively. A locus detected by marker KsuA1 was linked to Dn2 at a distance of 9.8 cM on the long arm of chromosome 7D, and a locus detected by marker ABC156 was 11.6 cM away from Dn4 on the short arm of chromosome 1D.Key words: Russian wheat aphid, RFLP markers, Triticum aestivum.

scholarly journals Field Screening of Lesotho and South African Wheat Cultivars for Russian Wheat Aphid Resistance

2016 ◽  
Vol 04 (05) ◽  
pp. 268-278 ◽  
Author(s):  
Astrid Jankielsohn ◽  
Pitso Masupha ◽  
Lintle Mohase
Keyword(s):  
South African ◽  
Russian Wheat Aphid ◽  
Aphid Resistance ◽  
Wheat Cultivars ◽  
Field Screening

“English is the best way to communicate” - South African Indian students’ blind spot towards the relevance of Zulu

2020 ◽  
Vol 34 (1) ◽  
pp. 155-171
Author(s):  
Sana Jeewa ◽  
Stephanie Rudwick
Keyword(s):  
Language Learning ◽  
South African ◽  
Undergraduate Students ◽  
Language Ideologies ◽  
Policy Decision ◽  
Blind Spot ◽  
Language Management ◽  
Kwazulu Natal ◽  
The Status ◽  
Indian Students

AbstractThe South African University of KwaZulu-Natal has developed an ambitious language policy aiming “to achieve for isiZulu the institutional and academic status of English” (UKZN LP 2006/2014). Part of this ambition is a mandatory Zulu language module that all undergraduate students have to pass if they cannot prove knowledge of the language. In this article, we examine attitudes of South African Indian students towards this compulsory module against the strained history and relationship between Zulu and Indian people in the province. Situated within the approach of Language Management Theory (LMT), our focus is on students as micro level actors who are affected by a macro level policy decision. Methodologically combining quantitative and qualitative tools, we attempt to find answers to the following broad question: What attitudes do South African Indian students have towards Zulu more generally and the UKZN module more specifically? The empirical findings show that students’ motivations to learn Zulu are more instrumental than integrative as the primary goal is to ‘pass’ the module. South African Indian students have developed a blind spot for the prevalence and significance of Zulu in the country which impacts negatively on the general attitudes towards the language more general and the module more specifically. Language ideologies that elevate the status of English in the country further hamper the success of Zulu language learning.

Integrative taxonomic methods reveal an incorrect synonymisation of the South African Pseudonereis podocirra (Schmarda) as the widespread Pseudonereis variegata (Grube) from Chile

2018 ◽  
Vol 32 (6) ◽  
pp. 1282 ◽  
Author(s):  
Jyothi Kara ◽  
Angus H. H. Macdonald ◽  
Carol A. Simon
Keyword(s):  
South Africa ◽  
South African ◽  
Species Delimitation ◽  
Haplotype Network ◽  
The Body ◽  
General Description ◽  
The South ◽  
Morphological Examination ◽  
Genetic Structuring ◽  
The Status

The nereidid Pseudonereis variegata (Grube, 1866) described from Chile includes 14 synonymised species from 10 type localities with a discontinuous distribution, but no taxonomic or molecular studies have investigated the status of this species outside Chile. Two synonymised species, Mastigonereis podocirra Schmarda, 1861 and Nereis (Nereilepas) stimpsonis Grube, 1866, were described from South Africa and investigated here using morphological examination. MtCOI species delimitation analyses and morphology were used to determine the status of P. variegata in South Africa. Morphological examination revealed that museum and freshly collected specimens from South Africa that conform to the general description of P. variegata are similar to M. podocirra and N. stimpsonis with respect to the consistent absence of homogomph spinigers in the inferior neuropodial fascicle, expanded notopodial ligules and the subterminal attachment of dorsal cirri in posterior parapodia. The synonymy of M. podocirra and N. stimpsonis as P. variegata are rejected and P. podocirra, comb. nov. is reinstated. Morphologically, Pseudonereis podocirra differed from specimens from Chile with regard to the numbers of paragnaths, the absence of homogomph spinigers and changes in parapodial morphology along the body. Independence of these species was further supported by genetic distances, automatic barcode gap discovery and multi-rate Poisson tree process species delimitation analyses of 77 mtCOI sequences. Haplotype network revealed no genetic structuring within the South African populations. http://zoobank.org/urn:lsid:zoobank.org:pub:F0B1A5AF-9CE9-4A43-ACCF-17117E1C2F21

scholarly journals Some facts and thoughts on the training and practice of Industrial Psychologists

1982 ◽  
Author(s):  
I. Van W Raubenheimer
Keyword(s):  
South African ◽  
Ethical Conduct ◽  
Industrial Psychology ◽  
Professional Behaviour ◽  
South African Universities ◽  
The Status ◽  
Training Of Personnel

Contributions made by South African universities over decades to the training of personnel practitioners are reviewed and the status of Industrial Psychology as a profession is discussed. A few misconceptions about ethical conduct are criticised in the light of the internationally accepted criteria of professional behaviour. OpsommingDie bydrae wat die Suid-Afrikaanse universiteite oor die dekades heen gelewer het tot die opleiding van personeelpraktisyns, en die stand van die bedryfsielkunde professie en praktyk word bespreek. Enkele dwalinge in bedryfsielkundige praktyk word nader toegelig en besweer aan die hand van internasionaal erkende norme.

scholarly journals Indigenous knowledge in the life sciences classroom: Science, pseudo-science or a missing link?

2012 ◽  
Vol 31 (1) ◽  
Author(s):  
Josef J. De Beer ◽  
Ben-Erik Van Wyk
Keyword(s):  
Indigenous Knowledge ◽  
South African ◽  
Life Sciences ◽  
Qualitative Inquiry ◽  
Knowledge Systems ◽  
Pedagogical Content ◽  
Indigenous Knowledge Systems ◽  
The Status ◽  
Classroom Science ◽  
Scientific Fields

Although the life sciences curriculum asks for the inclusion of indigenous knowledge systems in the classroom, it is either done very superficially by only providing an example or two, or ignored completely. This mixed-methods study (with emphasis on the qualitative inquiry) on the status of indigenous knowledge in the life sciences classroom in Gauteng and Limpopo, once again echoed what Rogan and Grayston (2003) reported: the South African curriculum process focuses too much on the what (the curriculum itself) at the expense of the how (the implementation of the curriculum). Although the progressive curriculum makes it clear that indigenous knowledge should be addressed, it provides very little guidance to teachers on how this should be done. Two problems are highlighted in this article: teachers’ lack of pedagogical content knowledge in addressing indigenous knowledge systems, as well as their poor understanding of the nature of science. A teacher’s social responsibility also entails making learners aware of the cultural and practical value of indigenous knowledge, and stimulating learners’ interest in scientific fields such as ethnobotany and chemotaxonomy.

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