• Determinate growth: Fixed shape/size (leaves, flowers)
• Indeterminate growth: Continuous growth (roots, stems)

Definition: In-vitro germination of seeds under aseptic conditions.

Key Principle: Obtain sterile explants and seedlings.

• Bypasses asymbiotic germination.
• Crucial for orchid production.
• Increases germination efficiency.

Definition: Aseptic cultivation of isolated embryo on nutrient medium.

Key Principle: Rescue immature embryos or overcome dormancy.

• Produces haploids.
• Prevents seed dormancy.
• Shortens breeding cycles.
• Prevents embryo abortion.
• Useful for early ripening fruits.

Meristem Tip Growth

Definition: Culture of apical meristem tips (0.2–0.5 mm).

Key Principle: Produce virus-free plants due to tip a-vascularity.

• Successful in herbaceous plants (e.g., Potato, banana).
• Enables virus-free plant production.
• Facilitates germplasm conservation.
• Used for transgenic plant production.

Definition: Culture of a single node or axillary bud.

Key Principle: High cytokinin medium to stimulate shoot proliferation.

• Simple micropropagation method.
• Yields disease-free plants.
• Easier isolation of phytoconstituents.

Callus Growth on Agar

Definition: Undifferentiated parenchymatous mass from explant.

Key Principle: Grown on agar medium, often with balanced hormones.

• Allows for chromosomal variation studies.
• Used for secondary metabolite extraction.
• Serves as a source for suspension culture.
• Applied in biochemical assays.

Cells in Liquid Medium

Definition: Cells or small aggregates grown in agitated liquid medium.

Key Principle: Promotes rapid cell division and uniform growth.

• Studies physiology & metabolism.
• Performs biotransformation.
• Used in genetic engineering.
• Induces somatic embryos & shoots.
• Avoids toxic product accumulation.

Definition: Culture of anther (microspores) or pollen.

Key Principle: Produces haploid plantlets from gametes.

• Facilitates mutation studies.
• Produces double haploids.
• Enables genetic recombination studies.
• Used for differentiation studies.

Definition: Isolated protoplasts (cells without cell walls) cultured.

Key Principle: Allows fusion for novel hybrids and regeneration.

• Methods: Enzymatic or Mechanical.
• Studies morphogenesis.
• Analyzes photosynthesis.
• Regenerates whole plants.
• Forms novel hybrids via fusion.

Agrobacterium-induced Roots

Hairy Roots in Bioreactor

Definition: Roots produced by infection with Agrobacterium rhizogenes (Ri plasmid).

Key Principle: High growth rate and secondary metabolite production without hormones.

• High secondary metabolite yield.
• Exhibits hormone-free growth.
• Characterized by fast growth.
• Useful for gene function analysis.
• Enables whole plant regeneration.

Definition: Cells immobilized in a matrix or bioreactor system.

Key Principle: Enhances cell stability and product recovery.

• Facilitates biotransformation.
• Protects cells in fermenters.
• Used in synthetic seed technology.
• Aids protoplast transfer.
• Supports long-term single cell culture.

MACRONUTRIENTS

• Elements required at > 0.5 mmol/L.
• E.g., Nitrogen (N), Phosphorus (P), Potassium (K), Calcium (Ca), Magnesium (Mg), Sulfur (S).

MICRONUTRIENTS

• Required in trace amounts.
• E.g., Iron (Fe), Manganese (Mn), Zinc (Zn), Boron (B), Copper (Cu), Molybdenum (Mo), Cobalt (Co).

CARBON SOURCE

• Supplies energy & carbon skeletons as cultures are heterotrophic.
• E.g., Sucrose (most common), Glucose, Maltose.

VITAMINS

• Act as coenzymes to support cell division and growth.
• E.g., Thiamine (B1), Pyridoxine (B6), Nicotinic acid (B3), Myo-inositol.

HORMONES (GROWTH REGULATORS)

• Influence growth and differentiation (e.g., auxins, cytokinins).

ADDITIVES

• Natural: Coconut milk, Yeast extract.
• Solidifying Agents: Agar (most common), Alginate.
• Special Additions: EDTA (iron chelation), Activated charcoal (toxin adsorption), Antibiotics (contamination).

AUXINS — ROOT INDUCTION

• Examples: IAA, IBA, NAA, 2,4-D.
• Functions: Root formation, Callus induction, Cell elongation.
• Exam Fact: High auxin → root & callus formation.

CYTOKININS — SHOOT INDUCTION

• Examples: Kinetin, BAP, Zeatin.
• Functions: Shoot initiation, Bud formation, Cell division.
• Exam Fact: High cytokinin → shoot formation.

GIBBERELLINS — GROWTH PROMOTION

• Example: GA₃.
• Functions: Stem elongation, Breaking dormancy.

PROPAGATION

• Micropropagation of medicinal plants.
• Somatic embryogenesis.
• Synthetic seed production.
• Biomass energy for forestry.

BREEDING & CONSERVATION

• Haploid plant production.
• Germplasm conservation.
• Rapid homozygous line development.

METABOLITE PRODUCTION

• Secondary metabolite extraction.
• Biotransformation studies.

TRANSGENIC PLANTS

• Development of GMOs with enhanced traits.
• Improved insect/herbicide resistance.
• Better nutritional quality (e.g., golden rice).

PLANT EXAMPLES

• Tobacco, Potato, Banana, Tomato.
• Rice, Carrot, Corn, Soybean.

KEY LIMITATION

• Must be eaten raw (cooking denatures antigens).

FIRST HUMAN TRIAL (1997)

• Transgenic potato expressed E. coli toxin B-subunit.
• Tested for diarrhea immunity.

ADVANTAGES

• Needle-free, Low cost, No cold chain, Easy storage.
• Oral administration, Suitable for developing regions.

IMPORTANCE & USES

• Cancer therapy research (colon, cervical).
• Combats infectious and autoimmune diseases.
• Potential for mass immunization.