Improvement and breeding
M. Momeni; A. Ghasemi Pirbalouti; A. Mousavi; H.A. Naghdibadi
Abstract
Background and objectives: Thymbra spicata L. belongs to the Lamiaceae family and is a rich source of aromatic compounds and essential oils. This research was conducted to study the effect of salicylic acid and chitosan elicitors on the growth indicators and DXR gene expression in T. spicata L. under ...
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Background and objectives: Thymbra spicata L. belongs to the Lamiaceae family and is a rich source of aromatic compounds and essential oils. This research was conducted to study the effect of salicylic acid and chitosan elicitors on the growth indicators and DXR gene expression in T. spicata L. under different levels of irrigation towards enhancing the performance of this medicinal plant in experimental pots in a greenhouse in Ilam province during 2017-18.Methodology: A factorial design was used with 15 treatments and three replications in a completely randomized study. Irrigation regimes at three levels of normal (A₁), 70% of field capacity (A₂), 40% of field capacity (A₃), and foliar spraying at five levels, including control (B₁), chitosan at concentrations of 0.5 g.l-1 (B₂) and 1 g.l-1 (B₃), salicylic acid foliar spraying at concentrations of 2.5 mM (B₄) and 5.0 mM (B₅) were used at the 10-12 leaf stage. To prepare chitosan and salicylic acid elicitors, the powders were dissolved in 5% acetic acid and then adjusted to desired concentrations with ddH2O. Irrigation regimes were applied three months after cultivation (15-20 cm seedlings). To apply the elicitors simultaneously with the water stress treatment, foliar spraying was done three times at ten-day intervals. Quantitative RT-PCR was used to investigate the expression changes of the DXR gene, which is one of the key genes in the carvacrol biosynthesis pathway. In this regard, total RNA was extracted, and cDNA was synthesized after assessment of its quantity and quality. With the aid of specific primers, the target sequence was amplified. Furthermore, using the GAPDH reference gene reported in Hyssop thyme, the gene expression level was investigated through the relative quantification method. The method of difference in cycle threshold (2-∆∆CT) and Relative Expression Software Tool (REST) were used to analyze the data.Results: The analysis of the variance table showed the effect of different levels of irrigation on all quantitative growth indices, including plant height, root length, number of main branches, root fresh and dry weight, leaf fresh weight, stem fresh and dry weight, except leaf dry weight, were significant (p<0.01). The interactive effect of low irrigation and foliar spray of salicylic acid and chitosan on root fresh weight, leaf fresh weight, and stem fresh weight was significant at 1%. Accordingly, the interaction effect of irrigation and foliar spraying on the dry weight of the stem was significant at the 5% probability level. The results showed that the interactive effect of irrigation and foliar spray on leaf dry weight, number of main branches, and root length was insignificant. In this study, DXR gene expression did not show many changes after applying two different levels of chitosan (0.5 and 1.0 g.l-1). In contrast, salicylic acid treatment with 2.5 mM was significant at 1% probability and caused an increase in gene expression. The transcript level of this gene increased 29.72 times after applying 5.0 mM of this solution, which was significant at the 1% level. The amount of low irrigation decreased this gene's expression.Conclusion: Based on the obtained data, the normal irrigation method is the most suitable for hyssop thyme plants regarding their growth indicators. Foliar spraying of chitosan at different levels did not significantly affect growth indices and DXR gene expression. At the same time, salicylic acid increased them in this species. As a result, salicylic acid elicitor can increase carvacrol yield and biosynthesis.
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.
S. Esmaili; M. Rafiei; M. Saidi; S. Beigi; Z. Tahmasebi; M. Mohammadi; M. Kohzadian
Abstract
Tomato early blight disease, caused by Alternaia solani fungus, is one of the most important diseases of tomato in the world, and also in Iran. In order to investigate the antifungal activity of some medicinal plants to control this fungus, separate experiments were conducted in a completely randomized ...
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Tomato early blight disease, caused by Alternaia solani fungus, is one of the most important diseases of tomato in the world, and also in Iran. In order to investigate the antifungal activity of some medicinal plants to control this fungus, separate experiments were conducted in a completely randomized design under in vitro and greenhouse conditions. In the first experiment, the effect of concentrations of 200, 400 and 600 ppm of hydro-alcoholic extract (70% methanol and 30% water) of Thymbra spicata L., Thymus eriocalyx (Ronniger) Jalas, Satureja khuzistanica Jamzad and Oliveria decumbents Vent. with the negative (distilled water) and positive (Daconil, 3 g l-1) controls on the growth of A. solani fungus was studied under in vitro conditions. The results of the first experiment indicated complete inhibiting of fungal colony growth in all treatments. In the second experiment, 72 hours after contamination of tomato plants with A. solani fungus in an isolated greenhouse, contaminated plants were sprayed with the above-mentioned treatments and monitored for the disease symptoms 14 days later. In the third experiment, the protective effect of the above-mentioned treatments was studied. The results of the second and third experiments showed that with an increase in the extract concentration, the inhibitory and protective effects of the treatments increased. Although all treatments reduced the disease severity compared to the control, the concentrations of 600 ppm of T. spicata, 600 ppm of T. eriocalyx and 400 ppm of T. spicata, respectively had the most effective inhibitory and protective effects on the growth of fungus studied. Therefore, the use of the above treatments is recommended as a practical method for biological control of A. solani.
F. MalekMaleki; N. Abasi; E. Sharifi Ashoorabadi; M. Barari; M.J. Zare
Abstract
This research was conducted to investigate the effect of row spacing on yield (performance), morphological indices and essential oil content of two ecotypes of Thymbra (Thymbra spicata L.) in field growing conditions during two years of 2016 and 2017. The experiment was conducted in factorial based on ...
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This research was conducted to investigate the effect of row spacing on yield (performance), morphological indices and essential oil content of two ecotypes of Thymbra (Thymbra spicata L.) in field growing conditions during two years of 2016 and 2017. The experiment was conducted in factorial based on randomized complete block design with three replications at the Research Farm of Faculty of Agriculture, Ilam University. The treatments consisted of three-row spacing (20, 30 and 45 cm) and two ecotypes (Malekshahi and Sumar). The results of the combined analysis revealed that plant spacing and ecotypes had a significant effect on many parameters such as dry matter yield of leaf and plant, percentage, essential oil yield, leaf area index, number of branches, number of flowers per plant and plant height. The comparison of the mean for simple and interaction effects of parameters showed that when row distance between plants increased up to 30 cm, plant dry matter yield, leaf area index, the number of branches and canopy diameter increased in the plant. According to the positive correlation of these parameters with essential oil yield, the highest yield of essential oil was observed in this treatment. Among the two ecotypes, the Malekshahi ecotype was superior to Sumar in terms of dry matter yield of leaf and plant, essential oil, percentage and yield, number of branches, canopy diameter and leaf area index. The results of two-year planting of Thymbra spicata indicated that the highest dry matter of plant yield, leaf area index, number of branches, canopy diameter, length of inflorescence and essential oil percentage were achieved in the second year of cultivation in the row spacing of 30 cm and Malekshahi ecotype.
