Citronela de Java (Cymbopogon winterianus Jowitt): efeito da sazonalidade e de reguladores vegetais sobre a multiplicação in vitro e rendimento do óleo essencial

Abstract

Citronella of Java (Cymbopogon winterianus Jowitt.) is an aromatic plant of great economical value, it is also well known in all over the world due to repellent characteristics to its essential oil in citronellal. The propagation in vitro is a good method to multiply citronella, due to the fact that the division of the citronella roots ordinarily used facilitates the cutting contamination. However, there are reports that citronella does not present good results in the propagation in vitro when collected in determined seasonal conditions. Therefore, the aim of this paper was to evaluate the effect of the seasonally about the propagation in vitro of citronella of Java, being used different concentration of IBA and BAP, as well as evaluating the income of the essential oil for each season. The explants were collected in each season of the year and inoculated in MS in addition to combination of IBA and BAP. At the end of 30 days the following variants had been evaluated: Height (cm), number of shootings, formation of callus, oxidation and contamination. In the realized conditions, was observed a good multiplication rate during the summer, being just necessary the addition of 1,0 mg/L-1 of BAP in the medium culture, commonly to this it did not have oxidation in this season. The height only presented significant result in the summer. It had formation of callus in the base of the explants either in the autumn or in the winter and in the summer, but in the summer it had a concomitant increase in the number of shootings. The oxidation was higher in the spring. (100% of oxidation). The contamination did not present significant results in any season, therefore, independent from seasonal condition. The extraction of the essential oil was accomplished in each season of the year by in Clevenger appliance. The great income of the essential oil was gotten in the winter with 1,37% of oil, when the plants were totally bloomy. Although the normal conditions of bloom of citronella in the south region is during the spring and in the beginning of the summer. The spring and the summer had 0, 77 and 0,76% income of essential oil, respective. In the autumn presented a lesser income, with 0,57% of essential oil