Here’s a professional, course-ready section on Temporary Immersion Systems (TIS) for Aquilaria Mass Propagation for COPI’s Biotechnological Propagation of Agarwood Course, suitable for SOP manuals, lab guides, and training materials:
Temporary Immersion Systems (TIS) in Aquilaria Propagation
1. Overview
Temporary Immersion Systems (TIS) are liquid-based tissue culture systems where explants are periodically immersed in nutrient medium, rather than being constantly submerged. TIS combines the advantages of liquid culture with reduced hyperhydricity and better aeration.
TIS enhances shoot multiplication rates, reduces labor, and supports scalable production of genetically stable Aquilaria plantlets.
2. Principle
- Explants are placed in a culture vessel with liquid medium
- Medium is intermittently flooded for a set duration using mechanical, pneumatic, or electronic timers
- Between immersions, explants are exposed to air, improving gas exchange and reducing hyperhydricity
Key Variables:
- Immersion frequency (e.g., 5–15 min per 3–6 h)
- Medium volume and nutrient concentration
- Aeration and vessel design
3. Advantages of TIS
| Advantage | Explanation |
|---|---|
| High multiplication rates | Explants receive more nutrients and growth regulators during immersion |
| Reduced hyperhydricity | Intermittent air exposure prevents excessive water uptake |
| Uniform growth | Improved light and nutrient distribution |
| Labor efficiency | Less frequent medium changes than semi-solid culture |
| Scalability | Can be adapted to bioreactors for mass propagation |
4. Application in Aquilaria Propagation
- Explant Preparation
- Use nodal segments or shoot tips from elite mother plants
- Ensure healthy, contamination-free explants
- Culture Medium
- MS, WPM, or customized agarwood medium
- Optimize cytokinin:auxin ratio for shoot multiplication
- Immersion Regime
- Example: 10 min immersion every 4 hours
- Monitor for hyperhydricity, leaf chlorosis, or abnormal growth
- Acclimatization Post-TIS
- Rooting in half-strength MS or CAM medium
- Transition to ex-vitro using well-drained substrate and humidity control
5. Key Considerations
- Avoid prolonged immersion to prevent hyperhydricity and tissue necrosis
- Maintain sterility; liquid cultures are more prone to contamination
- Monitor pH, aeration, and medium composition regularly
- Integrate molecular checks if scaling up for clonal fidelity
6. Key Principles for COPI Labs
- TIS is ideal for high-throughput shoot multiplication of Aquilaria
- Optimize immersion cycles and nutrient concentration for each clone
- Monitor explant health to minimize somaclonal variation
- Use direct organogenesis explants for true-to-type mass propagation
- Combine TIS with downstream rooting and ex-vitro acclimatization for plantation-ready plantlets
7. Course-Ready Key Statement
Temporary Immersion Systems (TIS) provide a scalable, efficient, and reproducible method for mass propagation of Aquilaria, increasing shoot multiplication rates, improving plantlet uniformity, and reducing labor and culture costs while maintaining genetic fidelity.
I can next:
- Create a visual infographic showing TIS workflow: explant loading → immersion cycles → shoot multiplication → rooting → ex-vitro transition
- Highlight advantages and monitoring points for COPI labs
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