In vitro photoautotrophic cultivation of Melocactus zehntneri: insights from allometric characteristics from germination to acclimatization

Abstract

Melocactus zehntneri is a species of ornamental relevance suffering anthropogenic pressures, putting its preservation at risk. Thus, alternatives for propagating and conserving this species are needed. This study evaluated the effect of photoautotrophic cultivation of M. zehntneri to produce plants well acclimated to natural conditions. The seeds underwent different imbibition times before in vitro germination. Besides the growth room, a greenhouse hosted the photoautotrophic cultivation of seedlings. Vermiculite replaced agar in the culture medium. The imbibition pre-treatment in distilled water and the growth environments affected some parameters linked to germination. The greenhouse provided better characteristics for plants grown in vitro and for acclimatization than those kept in the growth room. Plants cultivated and acclimated ex vitro in a greenhouse photoautotrophic environment showed improved characteristics regarding ornamental significance.