Plant tissue culture follows a sequence of stages, each with its own medium, environment and risks. Knowing them makes any protocol easier to read and any culture easier to troubleshoot.
Stage 0: Mother plant preparation
Healthy, true-to-type mother plants are selected and often pre-treated so that clean explants can be taken. Starting material quality sets the ceiling for everything after.
Stage I: Initiation
A small piece of tissue (an explant) is surface sterilised and placed on a nutrient medium under aseptic conditions. The goal is a clean, living culture. Contamination and browning are the typical problems.
Stage II: Multiplication
Cultures are divided and moved onto fresh medium at regular intervals. Cytokinins such as BAP push shoot formation. For banana, a clump of shoots is divided into new clumps, which multiplies stock rapidly.
Stage III: Rooting
Shoots are moved to a medium that encourages roots, often with an auxin such as NAA or IBA, or with reduced cytokinin. Roots give plantlets the ability to take up water after leaving the vessel.
Stage IV: Hardening (acclimatisation)
Plantlets leave the vessel and adjust to normal air, light and substrate. High humidity at first, reduced gradually, is the key. This is the stage where many programmes lose plants. See how to acclimatise TC plants and our acclimatisation guide.
Why the stages matter
- Each stage needs different media and plant growth regulators.
- Stage II drives volume and cost; Stage IV drives survival.
- Records at every transfer make problems traceable.
Read how to read a tissue culture protocol and see our propagation protocols.