REGENERATING PLANTS FROM IN-VITRO CULTURE OF BLACK LOCUST COTYLEDON AND LEAF EXPLANTS

A protocol to achieve efficient plant regeneration from juvenile black locust (Robinia pseudoacacia L.) explants is described. Direct adventitious shoots were induced from cotyledon explants on woody plant medium containing 22.2 muM BA and 0.4 muM 2,4-D. Shoots developed and new shoots were induced when the explants were transferred to medium without growth regulators. The effect of dark incubation on shoot regeneration from cotyledons indicated that 15 days of darkness resulted in a high regeneration frequency (91.7%). Adventitious shoot formation also was induced from sections of in vitro-derived leaves cultured in darkness on Murashige and Skoog medium supplemented with 4.4 muM BA and 24.6 muM IBA. A shoot regeneration frequency of 89% was obtained when explants were subcultured on a medium containing 4.4 muM BA and 0.5 muM IAA. Shoots were rooted on Schenk and Hildebrandt medium with or without IBA. Plantlets were acclimatized and grown in the greenhouse. Chemical names used: N-(phenylmethyl)-1H-purin-6-amine (BA); 2,4-dichlorophenoxyacetic acid (2,4-D); indole-3-acetic acid (IAA); indole-3-butyric acid (IBA).