Name: Luciana Barbosa Soares Chamoun
Type: MSc dissertation
Publication date: 22/02/2019
Advisor:
Name |
Role |
|---|---|
| Viviana Borges Corte | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| Elias Terra Werner | Internal Examiner * |
| Geraldo Rogério Faustini Cuzzuol | Internal Alternate * |
| Hildegardo Seibert França | Co advisor * |
| LEONARDO VALANDRO ZANETTI | External Alternate * |
| VITOR DE LAIA NASCIMENTO | External Examiner * |
| Viviana Borges Corte | Advisor * |
Summary: Allelopathyc effect of nanoemulsions produced from rosemary essential oil and
copaiba oil-resin
SUMMARY
Allelopathy is defined as the ability of plants to produce chemical compounds
that, when released into the environment, can influence positively or negatively
other plants. Essential oils are secondary metabolites obtained from different
parts of the plant, containing volatile compounds that may be associated with
biological effects. The objective of this study was to evaluate the allelopathic
potential of the essential oil of Rosmarinus officinalism L. (Rosemary) and oilresin of Copaifera spp. (Copaiba), in the form of nanoemulsions, so that the
efficiency of the compounds can be improved. The nanoemulsions were
produced with a concentration of 5% of the oils of Rosemary and Copaíba and,
later, diluted with distilled water to 5, 7 and 10 mg / mL. Germination, initial
growth, and enzymatic activity of the seeds of the species Lactuca sativa
(Lettuce) were evaluated. The experiment design was completely randomized
and for each treatment, 5 replications were made for the germination and growth
test. The germination and growth data were compared by analysis of variance
(ANOVA), followed by the Tukey test at 5% probability. The results showed that
the rosemary essential oil nanoemulsions had a negative allelopathic influence
on all attributes analyzed in the germination bioassays, such as: germination
percentage (% G), speed germination index (IVG), mean germination time
(TMG), leaf length and root length. This influence was dose dependent, thus, with
increasing concentration the effects are more pronounced. Such effects are due
to the specific action of their main chemical constituents or, possibly, by the
interaction between them. The monoterpene 1,8-cineol is reported as a potent
inhibitor and appears as the major constituent of the rosemary essential oil.
Copaiba nanoemulsions showed a positive influence on some evaluated
attributes. There was no influence on %G and shoot length. The lowest
concentrations of the copaiba oil nanoemulsions used in this study (5 and 7 mg /
mL) showed stimulatory allelopathic effect on root growth. The non-allelopathic
influence in the %G can be attributed to the chemical structure of the
sesquiterpene caryophyllene, a compound found in greater quantity in the
copaiba oil. These results indicate that the allelopathic influence is related to the
constitution and structure of the chemical components, as well as their
concentration.
Key words: Allelopathy ● Essential oils ● Nanoemulsions ● Enzymes.
