CHANGES IN THE STEROIDAL ALKALOID SOLASODINE DURING DEVELOPMENT OF SOLANUM-NIGRUM AND SOLANUM-INCANUM

All tested organs of Solanum nigrum and Solanum incanum elaborated sol asodine, but the levels varied widely. In both species, the smallest l eaves showed the highest alkaloid concentration. Maximum levels in S. incanum leaves were greater than twice those in S. nigrum. The absolut e amount of alkaloid per leaf increased during leaf development wherea s the concentration declined. The pattern of change in leaf alkaloid c oncentration with increasing age of the plant was different in the two species. The concentration of alkaloid in roots was higher than in th e stem in S. nigrum, but initially similar to stem levels in S. incanu m. Both organs showed alkaloid accumulation with time, although root l evels inexplicably fell in S. incanum after 20 weeks. Small unripe fru its of S. nigrum had a high concentration of solasodine, but both the concentration and the absolute amount per fruit decreased with fruit m aturation. The concentration and absolute amount of alkaloid also dimi nished in fruits of all developmental stages with increasing age of th e plant. S. incanum plants did not produce fruits during the study per iod. (C) 1997 Elsevier Science Ltd.