Elimination of Grapevine fanleaf virus from three Vitis vinifera cultivars by somatic embryogenesis

Indirect somatic embryogenesis was tested as a method for eradication of Grapevine fanleaf virus (GFLV) in three grapevine cultivars. Reverse transcriptase- polymerase chain reaction for GFLV detection was performed on tissues sampled at various steps of the embryogenic process: flower explants, embryogenic and non-embryogenic calli, single somatic embryos and regenerated plants. The virus was detected in all tested anthers and ovaries, while only one sample out of 63 regenerated plantlets was positive in the assay. Although GFLV was able to invade embryogenic calli and embryo-derived plantlets, in our experimental conditions GFLV eradication was obtained by somatic embryogenesis alone, without using heat therapy, with a success close to 100%. Assessment of the phytosanitary status of regenerated plants confirmed that GFLV was not detectable in the newly formed leaves 2 years after their transfer to greenhouse conditions.