Organogenesis in Cell Suspension Cultures of Atropa belladonna L. and Atropa belladonna Cultivar lutea Doll

Callus cultures have been initiated from excised cultured rootsof Atropa belladonna and A. belladonna cultivar lutea and usedto establish suspension cultures in a synthetic culture medium(referred to as SSM) containing 2.0 mg/1 -naphthaleneaceticacid (NAA). Visible cellular aggregates develop in these suspensioncultures and when such aggregates are cultured in an NAA-omittedmedium, large numbers of roots arise superficially on the aggregates.Root development is enhanced by incorporating into the auxin-freemedium either tropic acid or I-naphthoxyacetic acid and boththese substances can promote root initiation in the presenceof levels of NAA which alone suppress organogenesis. The aggregatesalso give rise under appropriate conditions of culture to shootsand to embryo-like structures. The nature and frequency of suchmorphogenesis in the aggregates is dependent not only upon thecomposition of the culture medium but upon the number and thelength of previous culture passages through which the callusand suspension cultures have been propagated in the SSM. Theultimate loss of morphogenetic potential in serially propagatedcallus is discussed. The structure of the aggregates in SSM and in the media promotingroot initiation is described. Examination of the aggregatesfor their content of alkaloids indicates that the major belladonnaalkaloids can only be detected in cultures forming roots.