Influence of the flower stage and culture medium on the induction of somatic embryogenesis from anther culture in Tunisian grapevine cultivars

Aims: The aim of this research is to identify the optimal flower developmental stage, in order to establish an efficient regeneration protocol via somatic embryogenesis in several local grapevine (Vitis vinifera L.) cultivars, using anther culture.Methods and results: Immature anthers sampled on fruity cuttings, at three flower developmental stages were cultured on three media [MS (1962), NN (1969) and CP (1987)] to which several phytohormonal combinations were added. Anthers, sampled at the « separated floral buds » stage, corresponding to the tetrad stage of microsporogenesis revealed to be the most appropriate for somatic embryogenesis compared to anthers sampled at the « separated clusters » and « early bloom » stages. Therefore, a unique medium, CP (1987) supplemented with 9 μM of 2,4-D and 11.35 μM of thidiazuron was established for the induction as well as the development of somatic embryos.Conclusion: The identification of an appropriate flower developmental stage and the optimization of a unique medium allowed establishing a reliable and repetitive regeneration system via somatic embryogenesis, in several local grapevine cultivars.Significance and impact of study: These embryogenic lines would be particularly appropriate as a target for the genetic transformation, directed towards the induction of tolerance to several biotic and abiotic stresses as well as for bioprospecting.