TITLE:
Essential Oils from the Leaves and Flowers of Callistemon viminalis: Chemical Characterization and Evaluation of the Insecticide and Antifungal Activities
AUTHORS:
Thais Aparecida Sales, Maria Das Graças Cardoso, Luiz Gustavo De Lima Guimarães, Karen Caroline Camargo, Danúbia.A.C.S Rezende, Rafaela Magalhães Brandão, Rafaela Vieira Souza, Vanúzia.R.F. Ferreira, Ana Ermelinda Marques, Maísa Lamounier Magalhães, David Lee Nelson
KEYWORDS:
Myzus persicae, Biological Activity, Phytopathogenic Fungi, Natural Products
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.8 No.10,
September
22,
2017
ABSTRACT: The
chemical compositions of the essential oils from the leaves and flowers of Callistemon viminalis and their
insecticide and fungitoxic activities were determined. The essential oil was
extracted by the hydrodistillation method using a modified Clevenger apparatus.
The chemical characterization was performed by GC-MS and GC-FID. The evaluation
of the insecticidal activity was performed with the Myzus persicae aphid, and the antifungal potential was determined via the inhibition of
the mycelial growth of Alternaria alternata, Fusarium oxysorum and Botrytis cinérea phytopathogenic fungi. The principal components of the essential oils
from the leaves and flowers were eucalyptol (84.60% and 61.47%), α-pinene (10.28% and 21.48%) and α-terpineol (2.59% and 2.79%),
respectively. The use of a 0.5% concentration of the essential oil from the
flowers influenced the preference of aphids and their reproduction. The number of
adult aphids decreased within a period of 48 hours in the presence of the essential
oil from the leaves. In the test with no chance of choice, the mean number of
adults decreased with both oils within 48 hours. No inhibition of the mycelial growth of
the A. alternate microorganism was observed in any of the treatments with the two
essential oils. However, the growth of F.
oxysporum and B. cinerea fungi was
inhibited. The mycelial growth of F.
oxysporum was inhibited with the concentration of 100 μL·Lˉ1 of
the oil from the flowers and 250 μL·Lˉ1 of the oil from the leaves.
The inhibition of the growth of B.
cinerea was observed at concentrations of 500 and 100 μL·Lˉ1 for the oils from the flowers and leaves, respectively. The essential oils
presented insecticidal and antifungal potentials. However, further studies are
needed for these oils to be used in integrated pest management.