Isolation of industrially valuable α-Cedrol from essential oil of Platycladus orientalis (Thuja orientalis) leaves using linear gradient counter current chromatography

Background: Natural plant products as larvicides could be considered as desirable alternatives to synthetic chemical insecticides for vector management. This study was undertaken to assess the mosquito larvicide activity of the essential oil from fresh leaves of Platycladus orientalis against two medically important species of mosquito vectors. Methods: Essential oil was extracted by hydrodistillation and analyzed with gas chromatography and mass spectrometry (GC-MS). Fresh leaves of P. orientalis tree (500g) were collected in June 2014 from Tehran, Iran and was authenticated at the Department of Medical Entomology and Vector Control, School of Public Health, Tehran University of Medical Sciences, Tehran, Iran. In addition, the larvicidal potential of oil was evaluated against late-3rd or young-4th instar larvae of Anopheles stephensi and Culex pipiens under laboratory condition. The mortality counts were made after 24h and LC50 and LC90 values were calculated. Results: Forty-six components in leaves of P. orientalis were identified. The major components were α-Pinene (20.17%), 3-Carene (14%) and Cedrol (9.51%). The LC50 values against An. stephensi and Cx. pipiens larvae were 11.67ppm and 18.60ppm after 24h, respectively. Conclusion: Platycladus orientalis oil could be considered as a natural larvicide for mosquito larval control. Keywords: Anopheles stephensi, Culex pipiens, Platycladus orientalis, Essential oil, Larvicide

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A Simple Chromosome Doubling Technique Is Effective for Three Species of Cupressaceae

HortScience ◽

10.21273/hortsci.47.6.712 ◽

2012 ◽

Vol 47 (6) ◽

pp. 712-714 ◽

Cited By ~ 1

Author(s):

Ryan N. Contreras

Keyword(s):

Simple Technique ◽

Chromosome Doubling ◽

Japanese Cedar ◽

Duration Of Treatment ◽

Thuja Occidentalis ◽

Platycladus Orientalis ◽

Color Retention ◽

Cotyledon Stage ◽

Optimal Duration ◽

Thuja Orientalis

Platycladus orientalis (L.) Franco (syn. Thuja orientalis L.), Thuja occidentalis L., and T. plicata D. Don. are conifers often used in the landscape. Most of the available cultivars of these species share the character of having foliage that turns an off-color during winter as a result of photoinhibition. Tetraploids of the related japanese-cedar [Cryptomeria japonica (L. f.) D. Don.] have exhibited greener color retention than diploids during winter and a recent report described a simple technique to double its chromosomes. The technique used to double the chromosome number of C. japonica was applied to the three species mentioned to determine if it would be effective for inducing polyploidy and, if so, optimal duration of treatment. Seedlings were treated at the cotyledon stage for 0 (control), 10, 20, or 30 days with an aqueous solution containing 150 μM oryzalin + 0.1% Tween® 20 using a standard household spray bottle that created a fine mist. No tetraploids were observed for any species in control treatments, indicating all recovered tetraploids resulted from applying oryzalin. Tetraploids were observed for all other treatments except T. plicata at 30 days. Efficacy ranged from 0% to 27.1% of transplanted seedlings being tetraploid. There was a quadratic relationship between duration of treatment and percent tetraploids in T. occidentalis and T. plicata and a linear relationship for P. orientalis. Based on regression analysis, the optimal duration of treatment was 20.5 days for T. occidentalis and 13.9 days for T. plicata. The highest percent tetraploids recovered for P. orientalis was at 30 days and it is unclear if increasing duration beyond this would continue increasing percent tetraploids recovered. Morphology was not useful in early identification of tetraploids for any species.

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