High regeneration potential in vitro of sunflower (Helianthus annuus L.) lines derived from interspecific hybridization

Successful selection of interspecific hybrid progenies with superior abilit y to regenerate shoots from apical meristems was performed in sunflower whi ch now allows for the development of lines for improved biotechnological ap plications. Early generations of interspecific hybrids originating from cro sses between the two H. annuus CMS lines `HA89' and 'Baso', and 9 wild spec ies were screened for their ability to regenerate in vitro. Evaluation of 3 6 progenies allowed to identify seven progenies from crosses involving H. m ollis, H. giganteus, H. strumosus, and H. decapetalus which showed a signif icantly higher regeneration potential than the commercial hybrid 'Albena' r egarding the number of shoots per explant. Among these progenies, 47.2 to 6 2.4% of explants produced shoots with an average of 2.3 to 3.5 shoots per c ultured explant. Regeneration in vitro was significantly determined by the genotype. More than half of the investigated interspecific hybrids performe d better than the inbred `HA89' demonstrating that the high regeneration po tential available in the wild species can be efficiently transferred to cul tivated sunflower. The seven progenies with high regeneration potential in vitro were characterised by agronomic performance in the field. Two of the interspecific hybrids derived from H. strumosus and H. decapetalus not only showed a superior regeneration potential but also proved to be competitive to commercial hybrids with regard to important agronomic traits, e.g. fat content and TGW.