Cytokinins, auxins and activated charcoal affect organogenesis and anatomical characteristics of shoot-tip cultures of Lisianthus [Eustoma grandiflorum (Raf.) Shinn]

Variants from seed-propagated Lisianthus [Eustoma grandiflorum (Raf.) Shinn ] were shoot-tip cultured to observe the effects of cytokinins, auxins and activated charcoal on organogenesis and anatomical characteristics. N-6-Ben zyladenine (BA) and kinetin at high concentrations (13.32-22.2 and 13.94-23 .23 mu M) resulted in good shoot formation but high percentages of hyperhyd ric shoots. Increased indole-3-acetic acid (IAA) and indole-3-butyric acid (IBA) concentrations favored root formation, while increased naphthaleneace tic acid concentration adversely affected loot formation. Both shoot and ro ot development were suppressed by activated charcoal. The highest percentag e of regeneration anti the largest number of glaucous shoots with an averag e of 15 shoots per explant after 4 wk of culture were obtained when the sho ot tips were cultured on MS (Murashige and Skoog, 1962) medium supplemented with 4.44 mu M BA and 1.47-4.92 mu M IAA and IBA. In vitro-grown leaves ha d a higher number of stomata than field-grown leaves but the length anti di ameter of stomata showed no significant difference between the two types. F ield-grown leaves had well-developed epicuticular was layers, which were no t observed on hyperhydric leaves. Hyperhydric plantlets could not survive w hen transplanted to soil, whereas glaucous plantlets survived in more than 80% of cases. Variation in soil type resulted ill a slight difference in pl antlet survival. Based on thr results of our experiment, this: protocol sho uld be useful for the rapid micropropagation of lisianthus.