COTYLEDONS - AN EXPLANT FOR ROUTINE REGENERATION OF SUNFLOWER PLANTS

The potential of plant regeneration from sunflower cotyledon explants was studied under conditions either to allow direct regeneration (orga nogenesis) or callus proliferation with high regeneration capacity. An alysis of histological modifications caused by tissue culture conditio ns showed that the regeneration protocol described here permitted the development of abundant meristematic centers in discrete regions of th e basal part of the cotyledon. The protocol presented here proved to b e suitable for the regeneration of 10 genotypes, among 20 assayed, inc luding commercial inbred lines and hybrids of common use for productio n in Argentina. Furthermore, Agrobacterium infection experiments showe d that basal halves of cotyledons were transformed, evidencing tumour proliferation.