Culture tube closure-type affects potato plantlets growth and chlorophyll contents

The effect of different hermetic and non-hermetic closure-types ( aluminum foil, cotton bung, cotton plug, polypropylene cap and Steristopper) on potato ( Solanum tuberosum L.) plantlets growth and chlorophyll contents was studied in three genotypes belonging to different maturity groups. Plantlets grown in culture tubes closed with aluminum foils and polypropylene caps had higher fresh mass and shoot length, but lower chlorophyll contents, higher senescence index and various morphological abnormalities. Non-hermetic closures like cotton plugs and Steristoppers were found optimum for plant growth without any morphological abnormalities. Besides, these plantlets exhibited low senescence index and had higher chlorophyll contents that favour acclimation to ex vitro conditions.