Study of Allelopathic Interaction of Essential Oils from Medicinal and Aromatic Plants on Seed Germination and Seedling Growth of Lettuce

Abstract

Medicinal and aromatic plants have the ability to transmit volatile allelochemicals and affect their surrounding organisms. In this regard, their interaction should also be considered. The inhibitory effects of 112 essential oils on lettuce seed and seedling were investigated by cotton swab method. Germination (G%), Mean germination time (MGT), Lethal of embryo (L%), dormancy (D%), radicle growth (R%), and hypocotyl growth (H%) were measured. Two methods were used for evaluating allelopathic interaction effects: the simplified modified dilution check-board technique (SMCT) and the isobologram. Thymus daenensis had the highest inhibitory effect on G% (IC50 = 2.9 ppm) and the most lethal effect on the embryo (LC50 = 7.2 ppm). Thymus transcaspicus, Dracocephalum moldavica, Artemisia sieberi and Amomum subulatum had the greatest effect on MGT. Ziziphora tenuior, Trachyspermum ammi and Pelargonium graveolens had the highest effect on D%. Origanum vulgare was the strongest growth inhibitor. The highest synergistic effect on G% was in A. subulatum + Mentha suaveolens, on H% was related to Perovskia abrotanoides + T. daenensis, and on R% was observed in Artemisia vulgaris + M. suaveolens. The results of this study can lead to identification of new phytotoxic compounds in EOs and control weeds more effectively.

Phytotoxicity of Essential Oils: Opportunities and Constraints for the Development of Biopesticides. A Review

“…However, even if fundamental interaction cannot be studied properly for hundreds of compounds, their diverse mechanisms of action can constitute a strong opportunity for synergistic effects and prevent adaptation by weed species. Interaction between different EOC can allow a reduction in the application, while still effectively preventing germination and weed growth [120].…”

The Essential Oil Composition of Trachymene Incisa Rudge Subsp. Incisa Rudge From Australia

“…Previous reports have confirmed that the phenology of the plant and the growing conditions can affect the essential oils of other species of the same family [33][34]. It has been noted that the density of seeds affects the germination of this species [7], so the competition between growth in the plants could also alter its chemistry as allelopathic compounds do [35][36][37]. In fact, the competition has been reported to have an effect on the phylogenetic signal and phenotypic plasticity in plant functional traits and to the root biomass [38--39].…”

The Essential Oil Composition of Trachymene incisa Rudge subsp. incisa Rudge from Australia

“…Previous reports have confirmed that the phenology of the plant and the growing conditions can affect the essential oils of other species of the same family [ 32 , 33 , 34 ]. It has been noted that the density of seeds affects the germination of this species [ 7 ], so the competition between growth in the plants could also alter its chemistry as allelopathic compounds do [ 35 , 36 , 37 ]. In fact, the competition has been reported to have an effect on the phylogenetic signal and phenotypic plasticity in plant functional traits and to the root biomass [ 38 , 39 ].…”