EFFICIENT SHOOT REGENERATION FROM LEAF EXPLANTS OF BETULA PENDULA, B. PUBESCENS AND B. NIGRA

The effects of zeatin, BA and IBA on shoot regeneration through callus from leaf explants of Betula pendula genotype B3, B. pubescens genotypes B1 and B2, B. nigra genotype B4 have been examined. The highest percent of leaf explants with shoot regeneration from callus was achieved when the medium was supplemented with 5 mg L^-1 zeatin, 5 mg L^-1 BA and 0.2 mg L^-1 IBA. It was shown that zeatin alone or in combination with IBA resulted in direct shoot regeneration from leaf explants while BA supported abundant callus formation with no shoot regeneration.