Medium-dependent response of grapevine somatic embryogenic cells

A set of novel media, combining significant changes in KNO3, NH4Cl, KH2PO4, CaCl2, MnSO4 and ZnSO4 concentrations have been designed for somatic embry ogenesis and plant regeneration in grapevine. Friable and white embryogenic calli, consisting of viable cells, were obtained for Cabernet Sauvignon, C hardonnay, Chasselas, Gamay, Gewurztraminer, Grenache, Merlot, Muscat, Pino t Noir, Portan, Riesling, Syrah and the root-stocks 110 Richter, 3309 Coude rc and S04. The sole ammonium content was shown to drive somatic grape cell s either in a proliferation phase or in a differentiation pathway, i.e. the transition from a type I callus to type II. For 14 genotypes, numerous tor pedo could be initiated which developed within similar to 30 days. The maxi mal torpedo conversion efficiencies reached 100% in Cabernet Sauvignon and Syrah. Plant regeneration efficiencies ranging from 4.75 +/- 4.92%, for Rie sling to 79.25 +/- 20.84%, for Syrah were reproducibly reached within 50-10 0 days. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.