|Budget Amount *help
¥2,300,000 (Direct Cost : ¥2,300,000)
Fiscal Year 1997 : ¥900,000 (Direct Cost : ¥900,000)
Fiscal Year 1996 : ¥1,400,000 (Direct Cost : ¥1,400,000)
Protoplast fusion was done between 3 fast-grown trees, Alnus firma, Betula platyphylla, and Populus alba. The optimal condition of protoplast fusion was as follows : cell density, 5x10^4/ml ; fusion buffer, 0.5M mannitol + 2.5mM CaCl_2 ; Alternate current, 200v/cm ; AC frequency, 1MHz ; Direct current, 2kV/cm ; pluse width, 100 mu sec.This condition of protoplast fusion gave fusion ratios of 31% for Alnus firma, 34% for Betula platyphylla, and 36% for Populus alba.
Cell suspension cultures derived from fused cells of Alnus x Betula developed into white cultures of Betula-like form, suggesting the hydrid cultures between Alnus and Betula.
From protoplast cultures of Betula x Populus, some shoots regenerated in MS medium containing 1 mu M NAA and 0.1 mu M 4-PU,suggesting that these shoots obtained were derived from fused protoplasts between both species, because Betula species can not differentiate any shoots in Ms medium containing NAA.
Fused cell cultures of Alnus x Populus developed into callus from which some shoots differentiated. These shoots rooted in MS medium containing 0.1 mu M NAA and 2.5 mu M IBA and developed into 5 plantlets with different characters.