BP105T • Unit 3Topic 1 of 2⏱ 5 Min Read

1. Cultivation Factors & Plant Growth Regulators (PGRs)

💡 Core Concept & Clinical Context:

While wild collection (unorganized harvesting from forests) leads to species depletion and batch-to-batch chemical inconsistency, controlled Cultivation ensures uniform botanical purity, higher yields of active secondary metabolites, year-round supply, and adherence to Good Agricultural Practices (GAP). Environmental factors influencing phytoconstituent synthesis include Altitude (e.g. Cinchona thrives at 1000-2000 m; Tea at 1500 m), Temperature (e.g. Cardamom requires humid tropical shade; Pyrethrum requires cool climates), Rainfall, Soil type (loamy, sandy, clay) and Soil pH. Plant Growth Regulators (PGRs) are organic phytohormones that modify plant physiological processes at minute concentrations.

Clinical Scenarios & Pharmacopoeial Examples:

1Classes and Pharmacognostic Applications of Phytohormones

Using plant growth regulators to enhance secondary metabolite yield.

Step-by-Step Breakdown:

•• Auxins (Indole-3-Acetic Acid - IAA, Naphthaleneacetic Acid - NAA, 2,4-D):

•- Promotes cell elongation, apical dominance, and adventitious root initiation in stem cuttings (used in vegetative propagation of medicinal shrubs like Cinchona and Rauwolfia).

•• Gibberellins (Gibberellic Acid - GA3):

•- Stimulates stem elongation, breaks seed dormancy, and increases leaf surface area in foliage crops (e.g., increases Belladonna and Mentha leaf biomass).

•• Cytokinins (Kinetin, Zeatin, 6-Benzylaminopurine - BAP):

•- Promotes cell division, chloroplast maturation, and delays leaf senescence; critical in plant tissue culture micropropagation.

•• Abscisic Acid (ABA - Stress Hormone):

•- Induces stomatal closure during drought stress; inhibits premature seed germination.

•• Ethylene (Gas / Ethephon):

•- Promotes fruit ripening (Senna pods, Papaya for papain) and stimulates latex exudation in Rubber and Opium.

📋Key Takeaways & Exam Highlights

Altitude: Cinchona (1000-2000 m for high Quinine content), Clove (sea level up to 900 m), Opium (temperate plains).
NPK Fertilizers: Nitrogen enhances leaf biomass in foliage drugs (Digitalis, Senna); Phosphorus promotes root growth in underground drugs (Rauwolfia, Ginger); Potassium enhances starch and alkaloid synthesis.
Bio-fertilizers: Nitrogen-fixing Rhizobium, Azotobacter, and Mycorrhizal fungi.

🇮🇳 हिन्दी व्याख्या (1. Cultivation Factors & Plant Growth Regulators (PGRs))

दवा के पौधों की खेती में ऊंचाई (Altitude), मिट्टी और तापमान का बड़ा असर होता है। सिनकोना ऊंचाई पर अच्छा उगता है। ऑक्सिन (Auxins) जड़ें निकालने में और जिबरेलिन (Gibberellin) पत्तियों और तने का आकार बढ़ाने में मदद करते हैं।