Tissue Culture & Plantlets per Subculture Cycle

Tissue culture (micropropagation) grows many genetically identical plantlets from a few starting cultures in a lab. At each subculture cycle every culture is divided and produces several new shoots — the multiplication rate — so the number of plantlets grows exponentially over successive cycles. This calculator projects how many plants that yields and how many survive to the field.

Gross cultures = starting cultures × (multiplication rate ^ number of cycles). For example, 10 starting cultures at a rate of 3 over 4 cycles give 10 × 3⁴ = 810 gross cultures. Because the rate compounds each cycle, even a modest rate produces a very large number after several cycles — the heart of why micropropagation scales so fast.

The multiplication rate is how many new usable shoots or plantlets each culture yields per subculture cycle — often around 3 to 5 depending on the crop, medium and stage. A higher rate or more cycles multiplies the gross total faster, but pushing the rate too hard can lower quality and raise the loss rate later.

Not every plantlet becomes a field-ready plant. Losses happen during rooting, hardening (acclimatisation from lab to open conditions) and transport. The survival rate you enter trims the gross cultures down to the net plants you can actually plant out, which is the figure that matters for planning sales and field area.

The fold increase is how many times your starting material has multiplied — gross cultures ÷ starting cultures, or simply rate ^ cycles. It shows the raw multiplying power of the protocol independent of how many cultures you began with, which is handy for comparing crops, media or cycle counts.

Hardening (acclimatisation) is the stage where lab-grown plantlets, used to humid sterile jars, are gradually adapted to normal humidity, light and microbes before field planting. It is the riskiest step — plants can wilt or succumb to disease — so survival here largely sets the gap between gross cultures and net field-ready plants.

Banana, potato, orchids and sugarcane are among the most common, along with many ornamentals, fruit rootstocks and forestry species. Micropropagation suits crops where clean, uniform, disease-free planting material at scale is valuable — which is exactly where exponential multiplication from a few cultures pays off.

Enough cycles to reach your target number, but not so many that quality drifts — too many cycles can raise the risk of somaclonal variation (off-types) and declining vigour. Work backwards from your target net plants, the multiplication rate and survival, and keep cycles to the minimum that meets demand.

They are solid planning figures. Real yields vary with crop, medium, the skill of the lab, contamination losses and how well hardening goes. Multiplication rate and survival are rarely constant across every cycle, so treat the output as a projection, validate against your lab's records, and build in a safety margin.