樱花离体培养芽外植体的建立

在生长季节的６月份，取约０．２ｃｍ大小、带叶原基的樱花（嫁接于樱桃砧上）芽心作为外植体。低浓度营养成份的软质启动培养基（１／４ＭＳ＋２％蔗糖＋０．５％琼脂，附加０．５ｍｇ／ＬＢＡＰ和０．０５ｍｇ／ＬＩＢＡ）能有效地防止外植体的褐化死亡；培养基表面无水膜、保持外植体干爽可避免胀水苗的发生；生长启动后，依次转入１／２ＭＳ和ＭＳ＋３％蔗糖＋０．８％琼脂培养基，附加１—２ｍｇ／ＬＢＡＰ和０．０５ｍｇ／ＬＩＢＡ，外植体快速生长而无玻璃状苗发生；每三周左右转管一次，约两个月后外植体生活力减退和茎不伸长的现象开始消失，之后培养基内不添加ＧＡ３外植体也能明显伸长（每次转管后茎可伸长２ｃｍ左右），而添加适当浓度的ＧＡ３（２ｍｇ／Ｌ）茎伸长可达４—５ｃｍ。

ESTABLISHMENT OF BUD EXPLANT OF JAPANESE LATE CHERRY (PRUNUS SERRULATA VAR. LANNESIANA)

Well-developed buds were isolated in June from two-year-old Japanese late cherry trees(P.serrulata var.lannesiana) grafted on Chinese cherry rootstocks. Primordial shoots of about 0.2 cm in size were excised as explants.The use of low-strength soft initiation medium (1/4MS+2% sucrose+0.5% agar,supplemented with 0.5mg/L BAP and O.05mg/L IBA) was effective in preventing browning of the explants. It was essential for freedom from waterlogging to culture explants on amedium surface free of liquid film and maintain the explants free of being wetted. An appropriate concentration of BAP (1-2mg/L) in combination with low concentration ofIBA(0.05mg/L) could minimize the occurence of vitrescence. Repeated transferring at about three week interval, helped overcome problems of vigor decline and rosettedshoots. After about three months of transferring, vigor decline eventually became less apparent and shoots could elongate about 2 cm on a fresh medium without GA 3 whereas stems of 4-5cm in length could be obtained with the addition of 2mg/L GA 3 to the medium.