Immature zygotic embryos of sunflower fertility restorer line 147 R were treated with ultrasound before plating to embryo culture medium. Some mutant plants were isolated and self-pollinated for several generations. New sunflower forms with inherited morphological and biochemical changes were obtained through selection and self-pollination. Genetic changes that occurred during the regeneration procedure included fifteen morphological and bio chemical characters. In this study, negative genetic changes were registered for most of the indices. Positive changes were registered for leaf petiole length and number of leaves. Plant height was the least stable of all characters under study. Mutation for resistance to the local population of Orobanche cumana (race A-E) was obtained from the susceptible Bulgarian control line 147 R. All five investigated mutant restorer lines possessed 100% resistance to Orobanche and stable inheritance in subsequent generations. Our results showed that mutagenesis in sunflower can be successfully used to develop new lines useful for heterosis breeding.