The citral was a major component of the EO in the absence of
AMF and Pb levels in the soil (45.08%). However, the citral production
decreased to trace under the increasing levels of Pb in the
soils without AMF (Table 2). The AMF inoculation did not affect
the production of citral. High levels of citral and geranial are economically
importantto the aroma and perfume industries (Barbosa
et al., 2008). Moreover,the synthesis of ionone and vitamin A is also
accomplished with citral (Lemos et al., 2013).
Geranial has a strong lemon aroma. It is an aromatic substance
widely used in the perfume industry because the citric aroma and is
also used in the food industry to complement the EO from lemons.
Geranial alsohas antimicrobial and insecticide benefits that create a
pheromone effectin insects. Some industries have a high interestin
this type of substance;itis worth investing in theAMFmanagement
to increase the production of citral and geranial with lemon grass
(Robacker and Hendry, 1977; Onawunmi, 1989).
Freitas et al. (2004) observed that M. arvensis increased the total
content of EO to 88% when the plants were inoculated with AMF.
The menthol content of EOs also increased at 89% in the treatments
without P, in comparison with the control. However, no increase in
EO ormenthol was observed withAMF inoculation when increasing
levels of P were applied to the soil. Little knowledge is available for
understanding the influence of AMF in the synthesis of EO in aromatic
plants.According to Smith and Read (2008), plants inoculated
with AMF present metabolic, physiological and anatomic changes
and produce various secondary metabolites as gibberellins, which
accumulate in high amounts in these plants. Gibberellins belong to