Toxicity and physiological effects of ajwain (Carum copticum, Apiaceae) essential oil and its major constituents against Tuta absoluta (Meyrick) (Lepidoptera: Gelechiidae).

Autor: Piri A; Department of Plant Protection, Faculty of Agriculture, University of Zabol, 98615-538, Zabol, Iran., Sahebzadeh N; Department of Plant Protection, Faculty of Agriculture, University of Zabol, 98615-538, Zabol, Iran., Zibaee A; Department of Plant Protection, Faculty of Agricultural Sciences, University of Guilan, 41635-1314, Rasht, Iran., Sendi JJ; Department of Plant Protection, Faculty of Agricultural Sciences, University of Guilan, 41635-1314, Rasht, Iran., Shamakhi L; Department of Plant Protection, Faculty of Agricultural Sciences, University of Guilan, 41635-1314, Rasht, Iran., Shahriari M; Department of Plant Protection, Faculty of Agricultural Sciences, University of Guilan, 41635-1314, Rasht, Iran. Electronic address: Shahriary.uoz@gmail.com.
Jazyk: angličtina
Zdroj: Chemosphere [Chemosphere] 2020 Oct; Vol. 256, pp. 127103. Date of Electronic Publication: 2020 May 17.
DOI: 10.1016/j.chemosphere.2020.127103
Abstrakt: The effects of Ajwain essential oil and its major constituents were investigated against newly fourth instar larvae of Tuta absoluta, a major pest of tomato cropping in Iran and other parts of the world. The study included individual efficacy of each compound and determination of their synergistic or antagonistic efficacy. We also determined the activities of detoxifying enzymes in treated insects. According to the results, the Ajwain essential oil and thymol showed the highest toxicity against T. absoluta larvae (LC 50  = 6.14 and 7.72 μL/mL, respectively, and LC 30  = 3.05 and 3.57 μL/mL, respectively). The ɤ-terpinene and p-cymene had lesser toxicity compared to other compounds. The larvicidal potency increased by binary mixtures of active constituents, such as thymol + p-cymene and thymol + ɤ-terpinene. On the other hand, ɤ-terpinene + p-cymene mixture demonstrated antagonistic effect on the larvae. The esterases and glutathione S-transferases were significantly increased in all treatments. Finally, our results revealed a significant inhibition of AChE activity in the treated larvae by all treatments except for ɤ-terpinene + p-cymene. In vitro experiments representing AChE inhibition with IC 50 values were recorded 0.370, 0.457, 0.528, 1.094 and 1.323 μL/mL for thymol + p-cymene, thymol + ɤ-terpinene, thymol, ɤ-terpinene and p-cymene, respectively. Thymol demonstrated significant potential as a controlling agent of T. absoluta larvae, both larvicidal, compatible with other compounds with strong AChE inhibition properties. These finding could pave the way for development of new botanicals based on EO constituents which should be completed with preparation of an efficient formulation and field trials.
Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
(Copyright © 2020 Elsevier Ltd. All rights reserved.)
Databáze: MEDLINE
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