A Study of Plant Growth Hormones on in Vitro Clonal Propagation of Fever Tea (Lippia Javanica): a Medicinal Shrub

In this abstract we describe about the influence of plant growth hormones for in vitro propagation of Lippia javanica, a woody aromatic shrub. This species has a good background of uses in ethnomedicinal practices by traditional healers of India and African countries. Bio-active compounds like 4-ethyl-nonacosane (1), (E)-2(3)-tagetenone epoxide (2), myrcenone (3), piperitenone (4), apigenin (5), cirsimaritin (6), 6- methoxyluteolin 4ʹ-methyl ether (7), 6-methoxyluteolin (8), 3ʹ,4ʹ,7-trimethyl ether (9), and 3-methyl-6-(1- methylethylidene)-cyclohex-2-en-1-one (10) are found in this plant. The objective of the present study was to find out conditions for effective clonal propagation of this shrub. Newly sprouted shoot tips were collected and then excised nodes were cultured on MS (Murashige and Skoog) medium fortified with different concentrations of 6-benzyleaminopurine (BAP), Kinetin (Kn), indole-3-acetic acid (IAA); sucrose (3%) and agar (0.7%) following surface sterilization with 0.1% HgCl2. Good result was found when explants were inoculated in MS + BAP [0.15 mg/l]. Shoots were regenerated up to 3.7cm in this composition at 4th week but in the case of multiplication, highest 2.42 shoots/explant were obtained at the 6th week in MS + BAP [0.25 mg/l]. When Kn was added to the medium, no considerable difference was observed in shoot growth. Combination of single auxin (IAA) and single cytokinins (either BAP or Kn) did not show good results. Again, multiple cytokinins and single auxin showed better shoot length (2.58cm) and average number of multiple shoot (2.40) in MS + BAP [1.0 mg/l] + Kn [0.5 mg/l] + IAA [0.25mg/l] at 6th week. Highest multiple shoot (2.71 shoots/explant) was observed at 6th week in MS + BAP [1.50mg/l] + Kn [1.00mg/l]. Micro-shoots were cut to separate from clump and implanted in root induction medium. Successful rooting was seen in MS + IBA [1.5mg/l]. After hardening and proper acclimatization plantlets were transplanted into soil. After four weeks of observation, no morphological variation was observed with the donor plant. This method of clonal propagation could play a role to fulfill the demand of its plantlets to commercial cultivators and this protocol could serve for in vitro conservation.