The formation of adventitious organs. II. The origin of buds formed on young adventitious roots of Populus nigra L. ‘Italica’

Young adventitious roots formed by tissue cultures or stem cuttings of the Lombardy poplar produce buds when treated with kinetin or 6-benzylaminopurine (BA). These buds originate from the superficial layers of the root, often close to the apex. When the buds are in a terminal position the apical tissues have been disturbed by callus formation. The normal activity of the apical root meristem is stopped by cytokinin, and in most cases the cells lose their meristematic appearance.