Effect of aluminium on in vitro rooting of birch (Betula pendula Roth.) and poplar (Populus tremula L. x P. alba L.) microcuttings

Poplar (Populus tremula L. x P. alba L.) and birch (Betula pendula Roth.) microcuttings obtained from in vitro cultures on media with aluminium (Al+) or without aluminium (Al-) were rooted in perlite saturated with a liquid 1/4 MS medium. Aluminium was added to the rooting medium in the form of aluminium sulphate or aluminium chloride. In the control, i.e. in the medium without aluminium, Al+ and Al- shoots usually developed similarly. Addition of aluminium to the rooting medium had a negative effect on the development of adventitious roots. Poplar and birch shoots obtained from cultures on media with aluminium (AI+) were distinguished by a greater tolerance of aluminium in the medium than shoots obtained from cultures on media without aluminium (A1-)