Somatic embryogenesis and plant regeneration of Vitis vinifera cultivars 'Macabeo' and 'Tempranillo'

Different experimental conditions have been compared to achieve a high efficiency in embryogenic calli initiation from 'Macabeo' and 'Tempranillo' anthers. Specifically, two stages of anther development were tested (corresponding to tetrad cells or uninucleate pollen), and direct culture of anthers was compared to culture after a cold treatment of inflorescences (4 degrees C during 48 h). In addition, two induction media (C-1(P) and B2), mainly differing by microelement and cytokinin levels, were evaluated. Experiment repeatability was also examined with a repetition of anther culture one week later. Callus initiation was similar in all media and treatments for both cultivars, usually starting from the anther filament. A simple protocol for efficient induction of embryogenesis in 'Macabeo' and 'Tempranillo' consisted in: (i) selecting the first inflorescence from hardwood cutting, (ii) excising anthers at uninucleate pollen stage without cold treatment of the infloreseences, (iii) incubating anthers on C-1(P) medium. The procedure used for embryo germination and plant regeneration, allowed to obtain a conversion rate up to 75 % in 'Macabeo' and 60 % in 'Tempranillo'. The protocol proposed represents the first regeneration system developed for the Spanish cultivars 'Macabeo' and 'Tempranillo'.