Abstract: Somatic embryogenesis and subsequent maintenance and plant regeneration from immature zygotic embryos of grapevine (Vitis vinifera L.‘Sinsaut’) were studied by manipulating plant growth regulator levels, light intensities and temperature. The results showed that the op timum p lant growth regulator combinations were 1.0 mg·L ^{- 1} 2,4-D for embryogenic callus induction and 1.0 mg·L ^{- 1} NAA + 0.5 mg·L ^{- 1} BA for embryos production and maintenance in weak light at 5℃ and 0.03 mg·L ^{- 1} NAA +0.5 mg·L ^{- 1} BA for somatic
embryos conversion and plant regeneration based on NN medium. The frequency of somatic embryogenesis was 37.5%, and the rate of plantlet regeneration from somatic embryos was 42.1%. The analysis of DNA content
determined by flow cytometry and chromosome counting of somatic embryos and regenerated plant clearly indicated that little chromosome changes were induced during the somatic embryogenesis, but the nuclearDNA content
and ploidy levels of the regenerated plants were stable and homogeneous to that of the donor plants.

Key words: Vitis vinifera, Immature zygotic embryo, Somatic embryo, Plant regeneration, Ploidy level