Abstract: The study of adventitious buds regeneration in immature embryo culture of sunflower (Helianthus annuus L.) was conducted.The experimental results indicated: (1) Im-mature embryos of sunflower at cotyledon stage had a strong ability to regenerate adventitious buds.It was easier for hypocotyl to regenerate adventitious buds than for cotyledon.(2)Genotype and medium were the critical factors ditermining the regeneration frequency of adventitious buds.Adventitious buds could be induced in most of the genotypes in the experiments.The average of the regeneration frequency was over 40%.The highest one was over 90%.The regeneration frequency of R-lines.hybrid F, and B-lines were higher than that of the common varieties.High content of sucrose.and suitable content of 6- BA in the media were favorable for adventitious bud regeneration.Adventitious buds could be reduced by ten kinds of media used in the experiment.(3)Most of the plants developed from the adventitious buds could normally produce seeds in greenhouse.

Key words: Sunflower (Heliauthus annuus L.), Immature embryo culture, Adventitious bud regeneration