ABSTRACT
The present study evaluated the influence of photon flux density and the type of culture vessel seal on the hardening of in vitro plants and on the survival of seedlings acclimatized of C. mucugensis subsp. mucugensis, in order to increase the survival during acclimatization. Micropropagated shoots were maintained under three different levels of photosynthetically active radiation (PAR): 60; 120 and 300 µmol m-2 s-1. Forty days after inoculation, the PVC that was used to close the tubes was exchanged for three different types of seals: PVC, caps and cotton. At 60 days of cultivation the plants were analyzed as anatomy, loss of water and growth. For acclimatization, some plants were transferred to green houses and covered with the top halves of PET bottles. The greatest in vitro growth and survival rates were obtained at light intensities of 60 µmol.m-2.s-1 of PAR. The results observed for all of the variables did not differ with the use of PVC or cap closures, but were significantly inferior when cotton closures were used, independent of the light regime. The species did not demonstrate phenotypic plasticity among the leaf characters examined. The best survival percentage results during acclimatization were obtained with the plants grown using PVC (76.12%) and caps (73.28%) under PAR intensities of 60 µmol m-2 s-1. These results indicated that conventional micropropagation is a viable method for producing plantlets of C. mucugensis subsp. mucugensis.
Key words:
Sempre-viva; Hardening; Aeration; Light
