Embryos and Plantlets from Cultured Anthers of Hybrid Grapevines

Abstract

Embryos and plantlets were produced in large numbers from callus formed by cultured anthers of hybrid grapevines (Vitis vinifera × Vitis rupestris). Anthers of Vitis vinifera produced small amounts of callus or failed to grow in vitro. For embryo formation anthers containing uninucleate microspores were chilled (4 °C) for 72 h before culture with Nitsch medium containing 2, 4-D (5μM) and benzyladenine (1 μM). Highest yields of embryos were with anthers cultured in darkness. For production of normal plantlets embryos required chilling (4 °C) for 2 weeks. Unchilled embryos produced mainly abnormal plantlets. Chilling was effective in promoting plantlet growth when applied at any stage of embryogeny. In grapes ability to produce plantlets from cultured anthers is a genetically-determined trait and maleness, as distinct from hermaphroditism, may be a predisposing factor. Callus derived from anthers contained both haploid and diploid cells but all plantlets produced so far are diploid. The genetic constitution of plantlets, whether they are diploids of somatic origin or diploids from spontaneously doubled haploid cells, is not yet known and is being determined by standard genetic methods.