Detached young leaves and their segments ofHeloniopsis orientalisproduced adventitious buds more readily than did detached mature leaves or their segments. Media composition had a greater influence on bud regeneration in segments of mature leaves than in segments of young ones. Detached young leaves and their fragments could form buds when placed on filter paper moistened with deionized water only or on an agar medium without the aid of exogenous inorganic salts and growth regulators. The presence of the midrib enhanced bud formation especially in segments of mature leaves. The number of buds in midrib-less segments treated with cytokinin was greater than in untreated segments with the midrib. These and other results suggest that regeneration is controlled by endogenous growth regulating substances supplied via vascular tissue.
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