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.
P. Azarkish; M. Moghaddam; A, Ghasemi Pirbaloti; F. Khakdan
Abstract
The Prangos genus is a medicinal plant belonging to the Apiaceae family, of which 15 species are found in Iran. The morphological traits at the flowering stage were studied to study the genetic diversity among 80 populations belonging to seven species P. hausslmechtii, P. lophoptera, P. corymbosa, P. ...
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The Prangos genus is a medicinal plant belonging to the Apiaceae family, of which 15 species are found in Iran. The morphological traits at the flowering stage were studied to study the genetic diversity among 80 populations belonging to seven species P. hausslmechtii, P. lophoptera, P. corymbosa, P. uloptera, P. acaulis, P. platychloena and P. ferulacea from six provinces Lorestan, Esfahan, Fars, Khuzestan, Kohgiluyeh & Buyer-Ahmad, and Chaharmahal & Bakhtiari. For this purpose, 10 plant samples were selected from each habitat and 22 quantitative traits were evaluated. Statistical parameters were calculated for the studied traits and coefficients of phenotypic variation were also determined as a measure of genetic diversity. The results of this study showed significant genetic variation within and between species. The results of ANOVA showed that the populations had significant differences in some of the studied traits (P<0.01), indicating high genetic variation among the populations. The highest coefficient of variance was observed for the number of lateral branches, number of umbels per plant, number of umbels per the main stem, the diameter of umbels per the main stem, leaves needle size, leaf width, main stem diameter, and lateral branches diameter, indicating high variability in the traits studied. Correlation coefficients between traits were different in the studied species and related to their genomic structure. In the principal component analysis, the first nine components explained 79.98% of the total variation in the evaluated traits. Based on cluster analysis, 80 populations were divided into four groups. The dendrogram obtained from cluster analysis revealed that morphological traits studied could differentiate some species from each other. Overall, the results of this research showed that there was a high level of genetic diversity in different species of Prangos spp.
A. Ghasemi Pirbalouti; A.R. Golparvar; M. Riyahi Dehkordi; A. Navid
Abstract
Seed germination is an important event in the life of every sexually reproduced higher plant. The seed of many medicinal plant species have dormancy, which they do not germinate unless specific environmental signals or events occur. This study was carried out to evaluation the effect of different treatments ...
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Seed germination is an important event in the life of every sexually reproduced higher plant. The seed of many medicinal plant species have dormancy, which they do not germinate unless specific environmental signals or events occur. This study was carried out to evaluation the effect of different treatments on seed dormancy and germination of Chahar Mahal & Bakhtiyari local thyme (Thymus daenensis) was done in completely randomized design (CRD) with three replications. These treatments were: gibberellic acid 100 PPM, gibberellic acid 500 PPM, gibberellic acid 1000 PPM, KN3 0.2%, thiourea 1 Molar and control. The results of analysis of variance (ANOVA) showed that the effect of various treatments on thyme seed germination percentage were significantly different (P<0.01). Treatments of KNO3 (0.2%) and Thiorae (1 Molar) have the highest and lowest seed germination percentage.
