2.2 Types of tissue culture systems 

Below is a professional, course-ready explanation of the types of plant tissue culture systems, contextualized specifically for Aquilaria propagation and aligned with COPI laboratory operations and SOP frameworks.

Types of Plant Tissue Culture Systems

(With Application to Aquilaria spp.)

1. Overview

Plant tissue culture systems are in-vitro techniques that exploit cellular totipotency to regenerate plant tissues, organs, or whole plants under controlled conditions. Different systems are selected based on propagation goals, genetic fidelity requirements, and scalability.

For Aquilaria, system choice directly affects:

  • Regeneration success
  • Genetic stability
  • Production cost
  • Suitability for commercial plantation deployment

2. Organ Culture Systems

2.1 Shoot Tip Culture

Description:
Culture of apical meristems or shoot tips.

Applications in Aquilaria:

  • Virus- and pathogen-free plant production
  • High genetic fidelity

Advantages:

  • Low somaclonal variation
  • Stable growth characteristics

Limitations:

  • Lower multiplication rate

COPI Use:
Elite clone preservation and nucleus stock development.

2.2 Nodal Culture

Description:
Culture of nodal segments containing axillary buds.

Applications in Aquilaria:

  • Rapid clonal multiplication

Advantages:

  • High regeneration efficiency
  • Simple protocol

Limitations:

  • Limited number of nodes per explant

COPI Use:
Primary system for commercial clonal propagation.

3. Callus Culture Systems

3.1 Callus Culture

Description:
Induction of unorganized, proliferating cell masses from explants.

Applications in Aquilaria:

  • Protocol development
  • Research on resin biosynthesis

Advantages:

  • High multiplication potential

Limitations:

  • Higher risk of somaclonal variation
  • Requires strict PGR control

COPI Use:
Research and experimental organogenesis only.

4. Organogenesis-Based Systems

4.1 Direct Organogenesis

Description:
Shoots and roots regenerate directly from explant tissues.

Advantages:

  • High genetic fidelity
  • Commercial reliability

Limitations:

  • Moderate multiplication rate

COPI Preference:
Main pathway for certified planting materials.

4.2 Indirect Organogenesis

Description:
Organ regeneration via callus phase.

Advantages:

  • High regeneration capacity

Limitations:

  • Increased genetic instability

COPI Use:
Limited to R&D and genotype screening.

5. Somatic Embryogenesis

Description:
Formation of embryo-like structures from somatic cells.

Potential Applications:

  • Long-term germplasm storage
  • Synthetic seed production

Limitations in Aquilaria:

  • Protocol complexity
  • Variable embryo conversion rates

COPI Status:
Advanced research phase only.

6. Cell Suspension Culture

Description:
Dispersed cells grown in liquid media.

Applications:

  • Secondary metabolite research
  • Resin biosynthesis studies

Limitations:

  • Not suitable for whole plant regeneration in Aquilaria

COPI Use:
Biochemical research support.

7. Temporary Immersion Systems (TIS)

Description:
Automated liquid culture systems with periodic immersion.

Advantages:

  • High multiplication rates
  • Reduced labor
  • Uniform nutrient uptake

Limitations:

  • High setup cost
  • Requires precise control

COPI Role:
Pilot-scale and commercial scaling platform.

8. Comparative Summary Table

Culture SystemRegeneration PathwayGenetic FidelityCOPI Application
Shoot tipDirectVery HighElite stock
Nodal cultureDirectHighMass propagation
Callus cultureIndirectMediumResearch
Direct organogenesisDirectVery HighCertified clones
Indirect organogenesisIndirectMediumExperimental
Somatic embryogenesisEmbryo-basedVariableAdvanced R&D
TISDirect/IndirectHighCommercial scaling

9. Strategic Selection for Aquilaria

COPI Best Practice:

  • Use direct organogenesis via nodal culture for production
  • Restrict callus-based systems to controlled R&D
  • Transition to TIS for cost-efficient scale-up

Course-Ready Key Statement

Selection of the appropriate tissue culture system determines the balance between propagation speed, genetic stability, and commercial reliability. For Aquilaria, COPI prioritizes direct organogenesis-based systems to ensure genetic fidelity, regulatory compliance, and predictable resin-yield performance.

If you want, I can:

  • Convert this into a decision-flow diagram (which system to use when)
  • Add it as Module 2.2 in your course manual
  • Create lab SOP selection guidelines
  • Prepare a one-page comparison infographic

Just tell me the next step.