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Résumé :
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In order to produce tetraploid genotypes of Vicia narbonensis (local population), seeds germinated during 96 hours were dropped in aqueous solution of colchicine at 5 X 10-4 concentration during 2 hours at 25degreeC in presence of permanent light. Selection of mixoploid plants was done using cytological tests including microscopic observations of some cellular organites (stomata, pollen) and morphological ones (third leaf and branch deformation, main apex growth...). These tests were used at different stages of plant growth; morphological observations was used on seedling in nursery in order to discard diploid forms and to simplify the transplantation into pots. Whereas, in order to determine polyploid genotypes, cytological tests were used during vegetative growth. Compared to diploid forms, polyploid ones were characterized by clear and persistent morphological deformation, large stomatic cells with more chloroplast and voluminous pollen grains with tetraedric shape. The diploid pollen was typically oval and tricolporate.
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