510 research outputs found

    Gene polymorphisms for elucidating the genetic structure of the heavy-metal hyperaccumulating trait in Thlaspi caerulescens and their cross-genera amplification in Brassicaceae.

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    Genetic polymorphism was investigated in Thlaspi caerulescens J. & C. Presl at 15 gene regions, of which seven have been identified to putatively play a role in heavy-metal tolerance or hyperaccumulation. Single nucleotide and length polymorphisms were assessed at four cleaved amplified polymorphic sequences (CAPS) and 11 simple sequence repeat (microsatellite) loci, respectively. The utility of these loci for genetic studies in T. caerulescens was measured among seven natural populations (135 individuals). Fourteen loci rendered polymorphism, and the number of alleles per locus varied from 2 to 5 and 1 to 27 for CAPS and microsatellites, respectively. Up to 12 alleles per locus were detected in a population. The global observed heterozygosity per population varied between 0.01 and 0.31. Additionally, cross-species/genera amplification of loci was investigated on eight other Brassicaceae (five individuals per population). Overall, 70% of the cross-species/genera amplifications were successful, and among them, more than 40% provided intraspecific polymorphisms within a single population. This indicates that such markers may, as well, allow comparative population genetic or mapping studies between and within several Brassicaceae, particularly for genes involved in traits such as heavy-metal tolerance and/or hyperaccumulation

    Gene polymorphisms for elucidating the genetic structure of the heavy-metal hyperaccumulating trait in Thlaspi caerulescens and their cross-genera amplification in Brassicaceae

    Get PDF
    Genetic polymorphism was investigated in Thlaspi caerulescens J. & C. Presl at 15 gene regions, of which seven have been identified to putatively play a role in heavy-metal tolerance or hyperaccumulation. Single nucleotide and length polymorphisms were assessed at four cleaved amplified polymorphic sequences (CAPS) and 11 simple sequence repeat (microsatellite) loci, respectively. The utility of these loci for genetic studies in T. caerulescens was measured among seven natural populations (135 individuals). Fourteen loci rendered polymorphism, and the number of alleles per locus varied from 2 to 5 and 1 to 27 for CAPS and microsatellites, respectively. Up to 12 alleles per locus were detected in a population. The global observed heterozygosity per population varied between 0.01 and 0.31. Additionally, cross-species/genera amplification of loci was investigated on eight other Brassicaceae (five individuals per population). Overall, 70% of the cross-species/genera amplifications were successful, and among them, more than 40% provided intraspecific polymorphisms within a single population. This indicates that such markers may, as well, allow comparative population genetic or mapping studies between and within several Brassicaceae, particularly for genes involved in traits such as heavy-metal tolerance and/or hyperaccumulatio

    Self-efficacy enhanced in a cross-cultural context through an initiative in under-resourced schools in KwaZulu-Natal, South Africa

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    This paper discusses the Khanyisa Programme, an initiative in KwaZulu-Natal, South Africa, where learners from under-resourced schools are supported by teachers and high achievers in Grade 11 and 12 from a previously advantaged state school under apartheid. A qualitative, evaluative study was undertaken to identify key elements in the ongoing success of the programme and collect participant suggestions for improvement. The findings, discussed within the framework of self-efficacy theory, identified enormous gains by Khanyisa learners, leading to vastly improved career prospects
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