How Thidiazuron Enhances Plant Growth and Tissue Culture Efficiency

Introduction
Thidiazuron (TDZ) is a highly active plant growth regulator (PGR) known for its cytokinin-like activity. Originally developed for use in cotton defoliation, it is now widely applied in plant tissue culture, horticulture, and agriculture due to its ability to regulate cell division, shoot regeneration, and organogenesis.

Key Features and Benefits

1. Potent Cytokinin Activity

   • Induces shoot formation in plant tissue cultures more effectively than traditional cytokinins (e.g., BAP, kinetin).

   • Promotes multiple shoot induction in difficult-to-propagate species.

2. Improves Micropropagation Efficiency

   • Widely used in the in vitro regeneration of crops like orchids, bananas, apples, tea, and medicinal herbs.

3. Cotton Defoliant

   • Encourages leaf drop before harvesting to improve fiber quality and harvesting efficiency.

4. Extended Shelf Life in Post-Harvest Crops

   • Delays leaf senescence and extends the visual appeal of ornamentals.

5. Low Effective Dose

   • Requires only trace concentrations (0.1–2.0 mg/L) in culture media, reducing overall costs.

Common Applications

How It Works

• Mimics cytokinin hormones, promoting cell division and shoot initiation.

• Inhibits auxin transport, thereby shifting the balance toward shoot formation rather than root or callus development.

• Regulates genes associated with cytokinin biosynthesis and response, making it effective even at low concentrations.

Application Guidelines

• Tissue Culture:

  • Typically used in Murashige and Skoog (MS) medium at 0.1–2.0 mg/L depending on species.

  • Often combined with auxins (like IBA or NAA) to control organogenesis balance.

• Cotton Defoliation:

  • Applied at 10–30 g/ha with or without other defoliants.

  • Ideal conditions: 25–30°C and high humidity for best results.

Precautions and Limitations

• Overuse in tissue culture may cause hyperhydricity or callus vitrification.

• Not suitable for all plant species—some may respond better to other PGRs.

• Handle with gloves and protective equipment due to PGR sensitivity.

FAQs

Q: Can thidiazuron be used in organic farming?
A: No, TDZ is synthetic and not approved under organic standards.

Q: Is it suitable for rooting?
A: It mainly promotes shoot formation. For rooting, auxins like IBA are preferred.

Q: Can it be stored long-term?
A: Yes, store in a cool, dry place away from light for extended stability.

Conclusion

Thidiazuron is a powerful tool in modern plant biotechnology and agriculture. Its high activity at low concentrations makes it ideal for micropropagation, crop defoliation, and research, helping growers and scientists maximize plant productivity and regeneration success.