Immature zygotic embryos of Quercus variabilis Bl. were excised and cultured on MS basal medium containing 0.25 mg/L 2,4-dichlorophenoxyace-tic acid and 0.5 mg/L 6-benzyl aminopurine. Callus was initiated from these embryos within 6 weeks.

• 以栓皮栎未成熟合子胚为外植体；在添加0.；25mg/L 2；4-D和0