Allelopathic activity of medicinal plant essential oils on seed germination and vigor of lettuce achenes

Cíntia Alvarenga Santos Fraga de Miranda, Maria das Graças Cardoso, Maria Laene Moreira de Carvalho, Samisia Maria Fernandes Machado, Marcos de Souza Gomes, Juliana de Andrade, Maria Luisa Teixeira

Abstract


In recent years, essential oils have gained commercial interest in the agricultural area, mainly for their allelopathic, insecticidal, antifungal, antimicrobial and antioxidant properties, and, also for their natural compounds, which have generally displayed low toxicity, relatively low cost and rapid degradation in the environment. Medicinal plants have emerged as potential suppliers of essential oils because of their ethnopharmacological utility. The aim of this study was to evaluate the allelopathic potential of essential oils extracted from fresh leaves of lemon grass (Cymbopogon citratus), wild basil (Ocimum gratissimum L.) and sweet basil (Ocimum basilicum L.) with regard to their major constituents (citral, eugenol and cineol, respectively) in different application forms (direct contact and the effect of volatile constituents) on the germination and vigor of lettuce seeds (cultivar Regina SF 3500). The effects of the oils and their major components were evaluated with regard to the variables: first germination count, total germination, GVI (germination velocity index), seedling dry weight and average lengths of shoots and lettuce roots. The essential oils from lemon grass and basil displayed allelopathic potentials on seed germination and vigor of lettuce achenes that can be assigned to their respective major constituents citral and eugenol. On the other hand, the allelopathic effect of the essential oil from basil was a consequence of the combined effect of all the components, regardless the application method.

 


Keywords


Volatile oils; Cymbopogon citratus; Ocimum gratissimum L.; Ocimum basilicum L.; Allelopathy.



DOI: http://dx.doi.org/10.5433/1679-0359.2015v36n3Supl1p1783

Semina: Ciênc. Agrár.
Londrina - PR
E-ISSN 1679-0359
DOI: 10.5433/1679-0359
E-mail: semina.agrarias@uel.br
Este obra está licenciado com uma Licença Creative Commons Atribuição-NãoComercial 4.0 Internacional