Dehydrocommersonine, a newly described glycoalkaloid, was isolated from root tissue initiated from a callus culture of Solanum chacoense. Tuber tissue of this plant introduction line did not contain commersonine or its dehydro compound. Callus of S. chacoense and three cultivars of Solanum tuberosum that failed to initiate roots were devoid of glycoalkaloids. Callus of S. tuberosum varieties Merrimack and Wauseon which had developed some roots were found to contain solanine and chaconine.