Effect of vessel type and growth regulators on micropropagation of Capsicum annuum

Leaves from 14-d-old Capsicum annuum cv. Anaheim seedlings were cultured on Murashige and Skoog (MS) medium containing different combinations of indole-3-acetic acid (IAA) and 6-benzyladenine (BA). After 3 months, cultures were transferred to new medium where BA was replaced with 9 microM isopentenyladenine to enhance the growth of shoot buds. Developing shoots were elongated and rooted on MS medium enriched with 9 microM indole-3-butyric acid. All cultures were maintained in baby jars covered with a clear polypropylene lid with or without microporous polypropylene membrane. Vessel type and plant growth regulators significantly affected callus morphogenic appearance, organogenesis and in vitro plantlet growth. Ventilated vessels supported photomixotrophic culture and improved regeneration and growth of plantlets. Higher plantlet dry mass and content of photosynthetic pigments, and lower stomatal density of plantlets grown in ventilated than in non-ventilated vessels facilitated ex vitro acclimation and growth.