Chemical composition, phytotoxic, and cytogenotoxic properties of essential oils from Psidium cauliflorum and P. acidum (Myrtaceae)

The search for bioherbicides has been encouraged, and plants used in food or with bioactivity have been studied. Therefore, this article aimed to investigate the bioherbicidal potential of essential oils from Psidium cauliflorum and P. acidum through a plant toxicity bioassay using Lactuca sativa and Sorghum bicolor. The seeds were treated with essential oils of both species, along with control groups treated with distilled water, dichloromethane, and glyphosate. Germination percentage (GP), germination speed index (GSI), root growth (RG), shoot length (SL), mitotic index (MI), chromosomal alterations (CA), and nuclear alterations (NA) were evaluated. The major compound of the essential oil of P. cauliflorum was alpha-pinene, and of P. acidum were trans-caryophyllene, beta-elemene, germacrene A, and alpha-copaene. The essential oils from both species exhibited phytotoxic effects. P. acidum oil inhibited sorghum RG and lettuce SL, while P. cauliflorum oil reduced GP, GSI, RG, and SL in both plants, indicating higher phytotoxicity than P. acidum and non-selective behavior. Cytotoxic investigations showed that both oils inhibited the MI. CA analysis revealed that P. cauliflorum oil exhibited aneugenic and clastogenic action mechanisms. The results demonstrate the bioherbicidal potential of P. cauliflorum essential oil, in addition to being non-selective and displaying a similar inhibition rate to glyphosate.