Biotechnological Strategies for Mass Propagation and Conservation of Tinospora cordifolia (Giloy): An In vitro Approach Using Plant Growth Regulators

Abstract

Tinospora cordifolia (Willd.) Miers ex Hook. f. & Thoms. (family Menispermaceae), commonly known as Giloy or Guduchi, is a medicinally important perennial climber of significant pharmaceutical and ethnobotanical value in the Indian traditional systems of Ayurveda, Siddha, and Unani. Increasing demand for this species in the herbal industry, combined with over-exploitation of wild populations and limitations of conventional vegetative propagation, has created an urgent need for reliable biotechnological strategies for its mass multiplication. The present study was undertaken to optimize in vitro culture conditions for large-scale propagation of T. cordifolia using nodal explants as the primary culture material. Explants were surface-sterilized using a sequential protocol of Bavistin (carbendazim, 1% w/v) and mercuric chloride (HgCl2, 0.1% w/v), with the optimal combination yielding 90% survival and 85% culture response. Nodal explants were cultured on Murashige and Skoog (MS) basal medium supplemented with varying concentrations and ratios of 6-Benzylaminopurine (BAP) and α-Naphthaleneacetic acid (NAA) to evaluate their effect on shoot organogenesis. Among all treatments tested, MS medium supplemented with BAP:NAA at a ratio of 3:2 (mg/L) designated Treatment H3 consistently recorded the highest morphogenetic performance across all parameters, including the earliest primordia initiation (within 10 days of inoculation), maximum nodal proliferation (4 nodes/explant at day 45), and the highest leaf count (3.5 leaves/explant at day 45). Hormone-free MS medium (control) did not support any organogenic response, confirming the indispensable role of exogenous plant growth regulators in T. cordifolia tissue culture. Growth arrest and fungal contamination observed in a proportion of cultures after day 20 were attributed to endophytic microorganisms persisting within the vascular tissue of the explants, which pose a known challenge in micropropagation of woody medicinal climbers. These findings establish a reproducible and effective protocol for in vitro shoot organogenesis of T. cordifolia and provide a foundation for further optimization of rooting, acclimatization, and large-scale clonal propagation of this invaluable medicinal plant.