Abstract:
Plumbago indica L., commonly known as Indian leadwort, is a perennial shrub
belonging to the family Plumbaginaceae. Native to Southeast Asia, it is widely
cultivated for its ornamental appeal and medicinal uses. The primary bioactive
compound of plumbagin, which gives the plant its pharmaceutical value, is
predominantly found in the roots. Unfortunately, the plant is rapidly declining in its
natural habitats due to over-harvesting and unsustainable collection practices.
Conventional propagation methods are challenging due to the plant's slow growth rate
and lack of viable seeds. Therefore, this study aimed to establish an efficient and rapid
in-vitro propagation technique to meet the growing commercial demand. Nodal
segments were collected from mature plants and sterilized using 0.3% Carbendazim and
10% Clorox with different exposure times (5 and 10 min). After a seven-day incubation
period, the healthy explants were transferred to MS medium supplemented with 1.0–5.0
mg/L BAP for shoot induction. Shoot elongation was further optimized by transferring
the induced shoot buds to MS medium with 1.0–5.0 mg/L GA3 and root induction was
achieved by transferring shoots to half-strength MS medium containing 0.2–0.8 mg/L
IBA. Fully developed and well-rooted plantlets were acclimatized in coir pellets before
being transferred to a soil (1:1) potting mixture. Completely Randomized Design (CRD)
was used in all experiments, there were fifteen replicates in each treatment and all the
cultures were randomized weekly. MINITAB 17 was used for the statistical analysis,
Analysis of variance (ANOVA) was performed and pair-wise comparisons were carried
out using Tukey‟s test. Results showed that the optimal sterilization method was 0.3%
Carbendazim for 10 minutes followed by 10% Clorox for 10 minutes, resulting in the
highest survival rate (83.34%). The highest number of shoots (3.4 ± 0.91) and the
longest shoot length (2.41 ± 0.21 cm) were obtained in MS medium containing 2.0
mg/L and 3.0 mg/L BAP, respectively and the highest shoot length increment (1.03 ±
0.45 cm) was observed with 4.0 mg/L GA3. MS medium supplemented with 0.4 mg/L
IBA which resulted in the highest mean number of roots (26.5 ± 3.54) and longest mean
root length (2.49 ± 0.31 cm). This study established an efficient in-vitro propagation
protocol for P. indica, addressing slow growth and seed scarcity, and recommending
scaling up for sustainable cultivation to reduce pressure on wild populations.
