Nematicidal activity of essential oils and volatiles derived from Portuguese aromatic flora against the pinewood nematode, Bursaphelenchus xylophilus

P. Barbosa, A. S. Lima, P. Vieira, L. S. Dias, M. T. Tinoco, J. G. Barroso, L. G. Pedro, A. C. Figueiredo, M. Mota

Abstract


Twenty seven essential oils, isolated from plants representing 11 families of Portuguese flora, were screened for their nematicidal activity against the pinewood nematode (PWN), Bursaphelenchus xylophilus. The essential oils were isolated by hydrodistillation and the volatiles by distillation-extraction, and both were analysed by GC and GC-MS. High nematicidal activity was achieved with essential oils from Chamaespartium tridentatum, Origanum vulgare, Satureja montana, Thymbra capitata, and Thymus caespititius. All of these essential oils had an estimated minimum inhibitory concentration ranging between 0.097 and 0.374 mg/ml and a lethal concentration necessary to kill 100% of the population (LC100) between 0.858 and 1.984 mg/ml. Good nematicidal activity was also obtained with the essential oil from Cymbopogon citratus. The dominant components of the effective oils were 1-octen-3-ol (9%), n-nonanal, and linalool (both 7%) in C. tridentatum, geranial (43%), neral (29%), and β-myrcene (25%) in C. citratus, carvacrol (36% and 39%), γ-terpinene (24% and 40%), and p-cymene (14% and 7%) in O. vulgare and S. montana, respectively, and carvacrol (75% and 65%, respectively) in T. capitata and T. caespititius. The other essential oils obtained from Portuguese flora yielded weak or no activity. Five essential oils with nematicidal activity against PWN are reported for the first time.

Keywords


medicinal and aromatic plants; biological control; Bursaphelenchus xylophilus; essential oils; nematicidal activity; pinewood nematode; Portugal; volatiles; Artemisia absinthium; Artemisia dracunculus; Calamintha baetica; Chamaespartium tridentatum; Chamomilla recutita; Cistus ladanifer; Crithmum maritimum; Cryptomeria japonica; Cymbopogon citratus; Foeniculum vulgare; Juniperus brevifolia; Laurus azorica; Laurus nobilis; Lavandula dentata; Lavandula luisieri; Lavandula stoechas; Lavandula viridis; Mentha pulegium; Myrtus communis; Origanum vulgare; Pittosporum undulatum; Salvia officinalis; Satureja montana; Thymbra capitata; Thymus caespititius; Thymus mastichina; Thymus zygis

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