Somatic embryogenesis of Vitis vinifera L. (cv Sugraone) from stigma and style culture

Somatic embryo and plant regeneration were induced from stigma and style culture of grapevine (Vitis vinifera L. cv. Sugraone). To obtain somatic embryogenesis, explants were cultured on Nitsch and Nitsch basal medium (NN) supplemented with 88 mM sucrose and various combinations of the auxin ?-naphthoxyacetic acid (NOA, 0-10 ?M) and the cytokinin 6-benzylaminopurine (BA, 0-9 ?M). Growth regulators (BA and NOA) in the culture medium were essential for induction of somatic embryogenesis since explants incubated on hormone-free medium never regenerated somatic embryos. Usually, the regenerated somatic embryos become visible as small white globular structures on the surface of the callus 3-4 months after culture initiation. The best embryogenic response (27 %) was obtained when stigma and style explants were cultured on NN medium supplemented with 5 ?M NOA and 9 ?M BA. Somatic embryos developed into plantlets when transferred to a hormone-free semisolid NN medium. 35 % of primary somatic embryos showed secondary embryogenesis.