Improvement and breeding
A. Negari; M. Jami Al-Ahmadi; G. Zamani
Abstract
Medicinal plants are a rich and valuable source of secondary metabolites that are strongly influenced by the environmental factors, especially drought stress. In this regard, a greenhouse experiment was conducted on Thymus vulgaris L. as split plots in a randomized complete block design with three replications. ...
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Medicinal plants are a rich and valuable source of secondary metabolites that are strongly influenced by the environmental factors, especially drought stress. In this regard, a greenhouse experiment was conducted on Thymus vulgaris L. as split plots in a randomized complete block design with three replications. The main plot included three levels of moisture supply (40, 65, and 90% of potting soil field capacity (FC)) and the sub-plot was the elicitors levels including (1) control: without elicitor, (2) 150 µM cyclodextrin (CYC), (3) 75 nM coronatine (COR) + 150 µM CYC, (4) 150 nM COR + 150 µM CYC, (5) 150 µM methyl jasmonate (MJ) + 150 µM CYC, and (6) 300 µM MJ + 150 µM CYC. Except for the essential oil percentage, the other traits including the leaves proline content, electrolyte leakage, relative water content, plant height, canopy diameter, dry and fresh weight of shoots, dry weight of leaves and stems, and weight of essential oil had a very significant correlation with each other. The highest amount of leaves proline was obtained form the interaction of elicitors (levels 4 and 6) and the 40% FC level of moisture supply (3.88 and 3.94 μmol g-1 fresh leaf weight, respectively). The highest amount of plant height (28.3 cm), canopy diameter (17 cm), and relative water content (79%) was observed at the 90% FC level of moisture supply. The highest percentage of essential oil was obtained in the treatment of non-application of elicitor (2.67%) and the highest essential oil weight per plant (0.092 g plant-1) was observed in the treatment of non-application of elicitor at the 65% FC level of moisture supply. The mild stress increased the essential oil yield and the elicitor treatments decreased it.
M.A. Kohanmoo; M. Modaresi; Z. Bagheri Kahkesh
Abstract
Heat stress causes morphological, physiological and biochemical changes in plants and affects plant growth. Given the mediator role of plant hormones in heat stress, this research was aimed to study the effect of spraying salicylic acid and jasmonic acid on the morphological and biochemical characters ...
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Heat stress causes morphological, physiological and biochemical changes in plants and affects plant growth. Given the mediator role of plant hormones in heat stress, this research was aimed to study the effect of spraying salicylic acid and jasmonic acid on the morphological and biochemical characters of Chamomile (Matricaria chamomilla L. cv: Bona) under natural heat stress conditions. This experiment was carried out as completely randomized blocks design with 3 replications. Four levels of salicylic acid (0, 12.5, 25, 50 mg.l-1) and four levels of jasmonic acid (0, 1, 1.5, 2 mg.l-1) were applied as treatments. The planting date was set in a way that more stages of plant growth and flowering period faced with heat stress. The morphological traits including plant height, capitol diameter, flower fresh weight, flower dry weight, and biochemical traits including essential oil and chamazulen percentage were studied. The analysis of variance showed that interaction effect of hormone salicylic acid and jasmonic acid on the flower fresh weight and chamazulen percentage was significant. In addition, the effect of jasmonic acid on chamazulen percentage was statistically significant. The best chamazulene percentage was observed in 2 mg.l-1 jasmonic acid treatment under heat stress.
