Improved in vitro rooting and acclimatization of Capsicum chinense Jacq. plantlets

In vitro conditions such as low light intensity, the levels of sucrose and other nutrients, and high relative humidity may cause anatomical and physiological changes that have negative effects on acclimatization of regenerated plants. The management of these conditions during in vitro culture could improve the plant ex vitro performance. The influences of light intensity, sucrose concentration, the nutritional composition of the culture medium, and culture container size on in vitro rooting and acclimatization were evaluated in Capsicum chinense cv. Naranja plants. The size of the culture container vessel did not affect plant growth. The best responses of the growth variables tested (plant height, number of leaves, number of roots, dry weight, and osmotic potential) and of survival and rooting were obtained with a photosynthetic photon flux density (PPFD) of 28 μmol m−2 s−1 and H medium with sucrose supplementation at either 1.5% or 3% (w/v). The combination of a PPFD of 28 μmol m−2 s−1 and H medium with 1.5% sucrose can be used for successful rooting of C. chinense adventitious shoots, to enhance the performance of the plantlets in the greenhouse or field and to reduce production costs. The factors studied during in vitro culture significantly influenced ex vitro growth.