Effect of toxic metals on the development of poplar (Populus tremula L. x P-alba L.) cultured in vitro.

Adventitious bud cultures were established by using buds of selected poplar clones (Populus tremula L. x P alba L.) as initial explants. The Murashige and Skoog medium (1/2 and 1/4 MS) was used for multiplication of shoots. Aluminium and copper were added to the medium in the form of sulphates. Copper, lead and aluminium were also added to the medium in the form of nitrates. Low concentrations of copper had no inhibitory effect on culture quality (i.e. degree of chlorosis and browning) and shoot development. High concentrations, especially of copper and lead, inhibited shoot and root development. Adventitious bud cultures derived from cultures grown on media with aluminium (Al+) were distinguished by a greater tolerance to aluminium and copper in the medium than shoot cultures derived from cultures grown on media without aluminium (Al-).