Optimization of aerial node mediated emergence and field performance in lower altitude of a higher altitude specific endangered medicinal plant, Valeriana jatamansi Jones

Abstract

A study was undertaken to develop a convenient, low cost, and an efficient technique for rapid propagation from aerial node of Valenaria jatamansi Jones directly in artificial soil formulations. The performance of aerial node mediated emergence was also evaluated in higher altitude (HA) as well as lower altitude (LA) to monitor the above and below ground growth parameters in a year in addition to active marker component analysis. The combination of supplemented artificial soil (SAS) having NPK, PSB and Tricoderma asperellum along with critical environment that initiated the high emergence as well as growth benefit at early time point (49 days). The two-node containing aerial cutting (wt.=0.580 ± 0.156g; emergence=87.383 ± 2.483%) showed maximum emergence as compared to one node containing aerial cutting (avg.=0.165 ± 0.016g; avg. emergence=63.883 ± 2.77). Concomitantly, injection of 2 μL of 6-Benzylaminopurine (6-BA; 0.25 mg.lt-1) into an aerial node also enhanced early time point growth benefits like significantly higher number of root initiation. The 4-month-old plant produced around 10 additional aerial nodes that could be explored for next round planting material production and original plant will be directly transplanted into main field with more than 90% survival rate without additional acclimatization and hardening steps. Therefore, a continuous and exponential rate of mass clonal propagation could be achieved from one-time requirement of aerial nodes. The 235 days exposure in lower altitude environment produced a significantly higher number of leaves, larger petiole length, smaller leaf length and breadth as compared to natural habitat grown plant in higher altitude. The above ground mass and root production were significantly higher in LA environment as compared to HA environment, but not in total rhizome production with variation in marker active component. The present study developed for the first time a new plant emergence from aerial node in SAS. Hence, it was breakthrough that aerial node produced Quality Planting Material (QPM) directly. Hence, it will be easy to bypass the costly process like tissue culture for clonal propagation of V. jatamansi, an endangered medicinal plant.