Crescimento e produção de constituintes voláteis de Ocimum basilicum e Mentha arvensis por cultura de tecidos

Abstract

The aim of this research was to study in vitro culture conditions for plantlet growth and volatile constituent production in the leaves of Ocimum basilicum and Mentha arvensis. Six experiments with both species were investigated: different culture media, different MS salt concentration; different segments and explant orientation; different growth regulators; developmental stage of the explant and comparison of the volatile fraction among mother plant, acclimatized and plantlet. Ocimum basilicum showed better growth in MS normal salt concentration. And, the nodal segments inoculated in horizontal orientation increased plantlet growth. The estragole was the most abundant constituent in the leaves in vitro. Medium supplemented with auxin promoted the highest plantlet growth and ANA was responsible for the largest increase in linalool in leaf. In growth parameters there was an increase during 100 days of culture. However, plantlet of O. basilicum should remain for up to 2 months in the same culture medium. After acclimatization occurred linalool accumulation in plants of O. basilicum. Mentha arvensis the different media provided plantlet growth in vitro. Lower MS salts concentrations enhancement plantlet growth. The nodal segments cultured in horizontal position showed better explant growth. And, different growth regulators influenced growth and chemical composition of the volatile fraction in plantlet. There was an increase in parameters analyzed during 100 days of culture and plantlet did no showed signs of nutritional deficiency. High levels of pulegone were observed in all experiments, but older culture the levels of menthol increase. In vitro leaves of M. arvensis tend to accumulate pulegone, but after acclimatization, the plant accumulates high levels of menthol close to the mother plant.