Interfamilial cell fusion among leaf protoplasts of Populus alba, Betula platyphylla and Alnus firma: assessment of electric treatment and invitro culture conditions

Abstract The optimal conditions for fusion of leaf protoplasts of Populus alba, Betula platyphylla, and Alnus firma by electric treatment were alternate current (AC) 200 V cm−1 in 2.5 mM CaCl2 for a pearl chain formation and direct current (DC) pulse of 100 μs at 2 kV  cm−1 After interfamilial cell fusion treatment, colonies were obtained using liquid media containing 2,4-D or NAA as an auxin and BA or CPPU as a cytokinin at 0.1, 1, or 10 µM in MS (Murashige and Skoog (1962) Physiol. Plant. 15: 473--497), 1/2salt MS, or NH4NO3-free MS containing 0.6 M mannitol and 3% sucrose (totaling 147 combinations). Two shoots after electric cell fusion treatment between P. alba and B. platyphylla, and 12 regenerated plants after electric cell fusion between P. alba and A. firma, were obtained from colonies induced on agar medium containing NAA, IBA, CPPU, and BA. Seven lines of the latter 12 plants which were regenerated later cultured in vitro had serrated leaves different from those of P. alba.