Biological effects of essential oils and extracts
D. Yazdani; M. Ebrahimi; A. Moodi; F. Nabati; M. Pouyan; S. Alvani; F. Jokar Shourijeh
Abstract
South Khorasan province is considered as the largest producer of jujube (Ziziphus jujuba Mill.) in Iran and the lives of a significant part of the locals depend on this product. The spread of jujube pest Monosteira alticarinata Ghauri in recent years, in addition to reducing the crop production, has ...
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South Khorasan province is considered as the largest producer of jujube (Ziziphus jujuba Mill.) in Iran and the lives of a significant part of the locals depend on this product. The spread of jujube pest Monosteira alticarinata Ghauri in recent years, in addition to reducing the crop production, has threatened the health of jujube consumers due to the widespread use of chemical pesticides to control this insect at harvest time. Therefore, the possibility of controlling this pest with formulations of some medicinal plants extracts and essential oils was investigated for the first time in this study. In the laboratory phase, the formulations included Capsicum annuum L. extract (30%)+Allium sativum L. oil (10%), Mentha piperita L. essential oil (10%)+Pelargonium graveolens L’Hér. essential oil (10%), Syzygium aromaticum L. essential oil (30%), Azadirachta indica A. Juss. oil (5%)+Thymus vulgaris L. essential oil (5%), and A. indica oil (5%)+ Th. vulgaris essential oil (5%)+potassium soap (50%) with deltamethrin (0.1%) and water as positive and negative controls, respectively were assayed in bioassay test. The results showed the high efficiency of the 5thformulation, which after four hours with a concentration of 2% caused 100% death of the pest and placed in the same statistical group with deltamethrin (92.5% efficiency in killing the pest). The results of Polo Plus software showed LC50 at a concentration of 0.91% of 5thformulation. The results of field data analysis showed the relative controlling potential of the formulation used in the field surveys, so that after 24, 48, and 72 hours, the insect control percentage at a concentration of 2% of this formulation was 27.43, 43.99, and 56.24%, respectively. These results showed that the fifth herbal formulation (2%) had a good ability to control M. alticarinata and could be used as an alternative to common chemical pesticides after official registration.
M. Ebrahimi; Gh.R. Zamani; Z. Alizadeh
Abstract
As an important medicinal plant in some industries such as pharmaceutical industry, the antioxidant capacity of pot marigold (Calendula officinalis L.) in conferring drought stress, as well as physiological and yield-related traits were studied. A complete randomized block design with three replications ...
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As an important medicinal plant in some industries such as pharmaceutical industry, the antioxidant capacity of pot marigold (Calendula officinalis L.) in conferring drought stress, as well as physiological and yield-related traits were studied. A complete randomized block design with three replications was carried out in the research greenhouse of Birjand University during 2014, 2015. Four levels of drought stress (including 80, 60, 40 and 20 percent of the available soil water content) and two plant types (medicinal and ornamental) were considered in this study. According to the results, with increasing drought severity, APX activity decreased and SOD and CAT activity initially increased and then decreased. Over accumulation of reactive oxygen species along with inefficiency of the antioxidant system had possibly resulted in the impaired enzymatic antioxidant efficiency in the highest level of drought stress. Proline content increased along with increasing drought intensity, so that it was up to fourfold in the highest level of drought stress, compared to non-stressed control. Although proline is an antioxidant compound, no relationship was found between proline accumulation with antioxidant enzymes. Carotenoids, chlorophyll content and chlorophyll index all decrease, and MDA content increased with increasing drought intensity, as a result of damages to chloroplast membranes. Reduced photochemical efficiency of photosystem II was another consequence of intensified water deficit. Drought stress also negatively affected yield related traits, so that dry weight (27%), height (32%), number of lateral branches (33%) and flowers (50%) and flower yield (60%) decreased. We also found that medicinal pot marigold (824.3 kg.ha-1) produced more flower than ornamental one (654.9 kg.ha-1). In conclusion, we found that enzymatic antioxidant system of pot marigold conferred a suitable ability to reduce adverse effects of drought-induced oxidative stress. Hence, increasing pot marigold’s antioxidant activity could result in increasing its physiological resistant to drought stress and consequently improves its yield components performance.