Agriculture and horticulture
A.A. Hatamnia
Abstract
Thymbra spicata L. (from Lamiaceae family) is distributed in large areas of Iran. In this study, the amount of total phenols and flavonoids, antioxidant activity, and percentage and essential oil composition in different ecotypes of this species from three different regions in Ilam province was evaluated. ...
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Thymbra spicata L. (from Lamiaceae family) is distributed in large areas of Iran. In this study, the amount of total phenols and flavonoids, antioxidant activity, and percentage and essential oil composition in different ecotypes of this species from three different regions in Ilam province was evaluated. The results showed that total phenols and flavonoids content was correlated with antioxidant activity positively and significantly, so that plant essential oil from Manesht Mountain with high phenols (8.6 mg gallic acid per g dry weight) and flavonoids (0.30 mg quercetin per g dry weight) content had the highest antioxidant activity, too. The main essential oil compound of the plant from regions with different ecological conditions was thymol (22.6-40.7%). Carvacrol, p-cymene, and γ-terpinene were the other main essential oil compounds of T. spicata from different regions. The results showed that the plant sample from Kaveran region and Manesht Mountain had the highest (2.4%) and lowest (1.4%) essential oil content, respectively. Overall, based on the results of the present study, it could be suggested that the essential oil percentage and composition of T. spicata depended not only to the genetic factors, but also to the ecological factors such as altitude, average annual temperature, and annual rainfall.
M. Tohidi; A. Vaziri; A.A. Hatamnia
Abstract
Some plants have negative effects on growth of the adjacent plants through excretion chemical Some plants have negative effects on the growth of adjacent plants through excretion chemical compounds known as allelopathy. In this study, the allelopathy effects of different parts of Heliotropium europaeum ...
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Some plants have negative effects on growth of the adjacent plants through excretion chemical Some plants have negative effects on the growth of adjacent plants through excretion chemical compounds known as allelopathy. In this study, the allelopathy effects of different parts of Heliotropium europaeum L. on seed germination and seedling growth of Raphanus sativus L. were investigated. The treatments included the extracts of root, stem, leaf, flower, fruit and distilled water (control) on seed germination of R. sativus. Also, 1% of stem powder, the whole plant as mulch and the whole plant mixed with soil were studied. To assess the allelopathic effects of different parts of H. europaeum, a number of growth parameters such as seed germination, stem length as well as dry and fresh weight were evaluated. The results indicated that all parts of the plant had a significant effect on germination of radish seeds, but their effects were different, so that the flower and stem extracts had the maximum inhibitory effect. The comparison of stem length, fresh and dry weight of R. sativus seedling in control and different treatments of H. europaeum showed that there was a significant difference between different treatments and control samples. Among different treatments, the inhibitor effects of stem extract was higher than other extracts. It was concluded that H. europaeum extract especially flower and stem extracts had a strong allelopathic effect and inhibited seed germination of R. sativus and could berecommended in production of natural herbicides.
