55 research outputs found

    A CYTOGENETIC AND PHENOTYPIC CHARACTERIZATION OF SOMATIC HYBRID PLANTS OBTAINED AFTER FUSION OF 2 DIFFERENT DIHAPLOID CLONES OF POTATO (SOLANUM-TUBEROSUM L)

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    Somatic hybrid plants of various ploidy levels obtained after chemical fusion between two dihaploid clones of potato Solanum tuberosum L. have been analysed by cytological, morphological and molecular methods. The hybrid nature of tetraploid and hexaploid plants and the genome dosage in hexaploid hybrids were confirmed by Giemsa C-banding. Tetraploid and hexaploid hybrids showed numerical as well as structural chromosome mutations. The latter occurred mainly in the nuclear organizing chromosome. The tetraploid hybrids were more vigorous than the dihaploid parents as demonstrated by an increase in height, enlargement of leaves, increase in the number of internodes, restored potential for flowering and increased tuber yield. The grouping of tetraploid somatic hybrids into various classes on the basis of leaf morphology revealed that plants with a full chromosome complement were more uniform than aneuploids. Many hexaploid somatic hybrids were also more vigorous than the dihaploid parents and could be grouped into two different classes on the basis of floral colour and tuber characteristics, the differences being due to their different dosage of parental genomes. Most of the tetraploid somatic hybrids showed pollen development halted at the tetrad stage as one of the parental clones contained a S. stoloniferum cytoplasm. However, one tetraploid plant produced pollen grains with high viability. The chloroplast genome in the hybrid plants was determined by RFLP analysis. All of the hybrids had a cpDNA pattern identical to one parent, which contained either S. tuberosum or S. stoloniferum cpDNA. A slight preference for S. tuberosum plastids were observed in hybrid plants. No correlation between pollen development and plastid type could be detected

    Rurality and education relations: Metro-centricity and local values inrural communities and rural schools

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    Based on ethnographic fieldwork in six different types of rural area and their schools in different parts of Sweden, this article identifies how rural schools relate to the local place and discusses some of the educational implications from this. Recurrent references to the local community were present in some schools and people there explicitly positioned themselves in the local rural context and valorised rurality positively in education exchanges, content and interactions, with positive effects on young people’s experiences of participation and inclusion. These factors tended to occur in sparsely populated areas. An emphasis on nature and its value as materially vital in people’s lives was present as was a critique of middle-class metrocentricity. Such values and critique seemed to be absent in other areas, where rurality was instead often represented along the metrocentric lines of a residual space in modernizing societies

    Inland water quality assessment: a joint European masters programme

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    At present, there is a European shortage of personnel qualified to adequately address the comprehensive scientific and regulatory requirements of the Water Framework Directive (WFD). The joint Masters programme described in this paper will provide students with the requisite expert knowledge and skills to progress the implementation of the WFD. Its development was financially supported by the European Commission because of its specific goal of producing qualified personnel in relation to the implementation of the WFD. Since its proposed structure acknowledges the educational intent of the Bologna Accord, it thereby provides a useful template for structuring a Masters degree-level programme in accordance with Bologna principles
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