Variations of Morphogenetic Behavior in Plant Tissue Cultures Ii. Petroselinum Hortense

Callus tissue derived several years ago from leaf petiole of parsley (Petroselinum hortense Hoffm., Umbelliferae) was grown on synthetic media. The callus is highly friable and easily dissociates into single cells and cell groups. In several nutrient media many nodular structures with negatively geotropic roots were formed. IAA inhibited root formation. In Murashige and Skoog's synthetic nutrient medium with 15–20 mg/liter adenine sulphate, embryoids were formed that simulated stages in the development of a zygotic embryo and its germination, and finally they developed into normal plantlets with shoots and roots. These embryoids arose after 10–12 weeks’ incubation from the meristematic middle cortex of roots already differentiated in the medium. Freshly isolated callus and coconut milk‐containing nutrient media were not necessary to have embryoid and plantlet formation in tissue cultures.