Somatic embryogenesis and organogenesis from immature embryo cotyledons of three sour cherry cultivars (Prunus cerasus L.)

Immature cotyledons of open-pollinated fruits from three sour cherry cultivars (Prunus cerasus L.) were excised and cultured on Murashige and Skoog medium supplemented with various combinations of auxin and cytokinin to induce somatic embryogenesis. Somatic embryogenesis occurred principally when using the combinations of 2,4-dichlorophenoxyacetic acid plus kinetin. Using a-naphthaleneacetic acid or 6-benzylaminopurine reduced the incidence of somatic embryogenesis. Conversely, formation of cotyledon-like structures, leaves, shoots and roots was enhanced. The addition of 0.1 mg lÿ1 3-indolebutyric acid to the inductive medium was beneficial to the induction of somatic embryogenesis. In a few cases, secondary somatic embryos formed and well-developed somatic embryos germinated. Of the three cultivars tested, `ScharoÈ' was less responsive than `Gerema' and `Schattenmorelle' when cultured under equivalent conditions. After trisectioning the cotyledons of cultivar `Gerema', morphogenic gradients were apparent in shoot and leaf formation but not in root and somatic embryo formation. The embryonic axes attached to the cotyledons of cultivar `Schattenmorelle' had an inhibitory effect on morphogenesis. # 2000 Elsevier Science B.V. All rights reserved.