IN VITRO PROPAGATION OF PLECTRANTHUS BARBATUS ANDREWS AS IMPORTANT MEDICINAL PLANT

Plectranthus barbatus Andrew (Coleus forskolii) is one of the important species of the genus Plectranthus (Coleus) belonging to family Lamiaceae, with a many of traditional medicinal uses in India. C. forskolii is only known source of forskolin; a compound with a many uses in pharmaceutical industries. C. forskolii was lack in Egyptian flora. Moreover, there were no previously studies on this plant in Egypt. Therefore, the present study used tool of biotechnology to conserve the stocks of this plant by micropropagation. C. forskolii seedlings came from its native Thailand at June 2013 and were put in the greenhouse in Desert Research Center for creating an efficient micropropagation protocol. The study was carried out on the effect of growth regulators (cytokinins and auxins) on different micropropagation stages of the explants. In multiplication stage, initiated shoots were cultured on MS medium supplemented with various concentrations (0.5, 1.0, 1.5 and 2.0 mg/L) of cytokinins (6-benzylaminopurine (BA), Kinetin ( KIN) and Thidiazuron (TDZ). The mean number of axillary shoots per explant of C. forskolii reached the highest value 6.19 ±0.573 on MS medium containing 2.0mg/L TDZ. Where, the highest value of mean length was 6.44± 0.310 cm on MS medium containing 1.0 mg/L KIN. The mean number of roots / explant of C. forskolii reached the highest value and the mean length were 30.00 ± 0.577 and 11.8±0.860 cm respectively, on 1/2 MS medium containing 0.5mg/L indole-3-butyric acid(IBA). While, the highest value of shoot length was 11.8±0.860 cm on 1/2 MS medium containing  2.0mg/L naphthalene acetic acid (NAA). A percentage of 83% of rooted plantlets were successfully acclimatized after four weeks and grown normally in the greenhouse in sterile soil mixture of garden soil,  vermiculate and sand (2:1:1/v/v/v). The protocol could be cost effective and useful in germplasm conservation and delivery of tissue cultured Coleus plants.