Interactions of culture vessels, media volume, culture density, and carbondioxide levels on lettuce and spearmint shoot growth in vitro

The influence of culture chamber capacity, medium volume and culture densit y on the growth yields of lettuce (Lactuca sativa L.) and spearmint (Mentha spicata L.) shoots were determined in an environment containing either 350 or 10,000 mu mol mol(-1) CO2 after 8 weeks of incubation. High positive co rrelations occurred between the culture vessel capacity and spearmint fresh weight, leaf number, root number, and shoot number. Similarly, high positi ve correlations occurred between culture vessel capacity and lettuce fresh weight, leaf number, and root number. Higher fresh weights, leaf numbers, a nd root numbers were obtained from lettuce and spearmint shoots when cultur ed in 1-quart Mason jars containing 100- or 150-ml aliquots of medium compa red to jars containing 25- or 50-ml aliquots of medium within an environmen t containing either 350 or 10,000 mu mol mol(-1) CO2. High culture density decreased growth yields, and this phenomenon could only be slightly off-set by the employment of an elevated CO2 environment or larger culture vessels .