FACTORS AFFECTING IN VITRO PROPAGATION AND CHROMATOGRAPHIC ANALYSIS OF COMPOUNDS IN HYPTIS MARRUBIOIDES EPL., A THREATENED MEDICINAL PLANT

The factors that influence micropropagation and the production of volatile compounds in Hyptis marrubioides plantlets were investigated. We performed 4 experiments as follows: culture medium volumes (10, 20, 30, and 40 ml); explant orientation (vertical and horizontal); positions of nodal segments (1st, 2nd, 3rd, and 4th) and multiplication rate as a function of explant origin was examined. After 40 to 45 days, shoot length, root length, shoot dry weight, root dry weight, number of shoots, and number of nodes were determined. The multiplication rate was determined from 3 subcultures using apical and nodal segments as explants. The best grew in vitro when 40 ml of culture medium was used and nodal segments containing 2 pairs of buds were inoculated in the horizontal position. The positions closer to the apex of explants exhibited longest shoot length, most accumulated SDW and RDW, and longest RL. Largest multiplication rate (4.06) was obtained from third subculture using apical buds as the explant source. Plants grown in vivo and in vitro were analyzed to determine their essential oil components. Nodal culture method is effective for micropropagation of H. marrubioides. Plants grown in greenhouse, wild and in vitro do not affect the chemical composition of the volatile fraction.