Complete plant regeneration of Valeriana wallichii DC. on auxin enriched medium and phytochemical analysis

Abstract

Valeriana wallichii DC. (Valerianaceae) is a well-known medicinal herb distributed in Northwest Himalayas. The herb is utilized in the treatment of numerous ailments and diseases such as diarrhoea, diabeties, gastrospans, ulcer and wound healing, etc. Overexploitation, especially collection of rhizomes on a large scale for the medicinal purpose has significantly declined the availability of the herb in natural stands. Hence, there is a requirement of development of cultivation practices and protocol for mass propagation to achieve sustained utilization along with conservation of the species. In the present study, in-vitro culture of nodal segments on MS+2iP+IAA+2,4-D and MS+2iP+IAA+NAA resulted in multiple shoot induction along with regeneration of in-vitro roots on the same medium making the protocol cost-effective, efficient and comparatively less time-consuming. Moreover, the regeneration of adventitious roots from regenerated shoots enhanced the total number of plants obtained per explant as shoots with adventitious roots were individually excised and were transferred to natural conditions through the process of acclimatization. GC-MS analysis of a methanolic extract of leaves of the mother plant and micropropagated plant revealed the presence of 37 and 36 phytocompounds respectively. Phytocompounds including eucalyptol, neophytidiene, hexadecenoic acid, dimethyl palmitamine were identified to be present in the leaves of both mother and micropropagated plants whereas other compounds such as eicosyne, lilial, behenic alcohol were confined to be present in extract prepared from leaves of mother plant. Similary some phytocompounds (phytol, vinicizer, retinol) were detected in methanolic extract prepared from leaves of micropropagated plants.