Efficient GA₃-assisted plant regeneration from cell suspensions of three grape genotypes via somatic embryogenesis

Abstract

Petioles from in vitro grown plants of interspecific grapevine hybrids cvs `Bianca', `Podarok Magaracha' and `Intervitis Magaracha' were cultured on solid NN medium supplemented with 2,4-D and BA at various concentrations. The callus developed was cultured in liquid NN medium supplemented with 0.5 mg l<sup>−1</sup> BA to induce formation of somatic embryos. Somatic embryos of globular and heart-stage developed in suspensions of `Podarok Magaracha' and `Intervitis Magaracha'. In contrast, `Bianca' did not undergo embryogenesis beyond globular stage. This made it necessary to perform subculture of the suspensions to HTE liquid medium supplemented with 0.2 mg l⁻¹ BA for the development of globular embryos into heart stage. Heart-stage embryos developed into torpedo-stage after subculturing suspensions of all three cultivars to liquid HTE medium supplemented with 0.1 mg l⁻¹ IAA and 30 mg l⁻¹ sodium hummate. Torpedo-stage embryo suspensions were subcultured in liquid HTE medium supplemented with 0.5 mg l⁻¹ BA, 0.5 mg l⁻¹ GA₃ and 0.5 mg l⁻¹ GA₃ + 0.2 mg l⁻¹ BA. After 12 days of incubation, plantlets were cultured on solid M2MS medium: without growth regulators and with 0.5 mg l⁻¹ BA. Plantlets that developed in liquid HTE media with 0.5 mg l⁻¹ GA₃ or 0.5 mg l⁻¹ GA₃ + 0.2 mg l⁻¹ BA produced 82–90% shoots on solid M2MS medium with 0.5 mg l⁻¹ BA after 50 days of culture.