Agriculture and horticulture
F. Salarpour Qhoraba; H. Farahbakhsh
Abstract
To investigate the effects of chitosan foliar application on the various physiological and biochemical (proline, protein, antioxidant enzymes, and percentage and essential oil yield) characteristics and dry matter yield of thyme (Thymus vulgaris L.) under drought stress conditions, a split-plot experiment ...
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To investigate the effects of chitosan foliar application on the various physiological and biochemical (proline, protein, antioxidant enzymes, and percentage and essential oil yield) characteristics and dry matter yield of thyme (Thymus vulgaris L.) under drought stress conditions, a split-plot experiment was conducted in a randomized complete block design with three replications in Lalehzar city, Bardsir county, Kerman province in 2019. The drought stress at four levels (35, 50, 65, and 80% of available moisture discharge) and the chitosan concentration at five levels (0, 0.2, 0.5, 1.0, and 1.5 gram chitosan per liter of acetic acid) were considered as the main and sub plots, respectively. The results showed that the drought stress increased proline, antioxidant enzymes, and percentage and essential oil yield and decreased the dry matter yield significantly. The proline, antioxidant enzymes, dry matter yield, and essential oil percentage increased significantly with increasing the chitosan concentration, which resulted in a significant increase in the essential oil yield as the most important quality index in thyme. The protein and gayacol peroxidase enzyme were not affected by chitosan foliar application. In general, the results of this research showed that the higher chitosan concentrations (1.5 gram chitosan per liter of acetic acid) were more effective in ameliorating the damages induced by the drought stress and achieving the higher yield.
Kh. Ahmadi; H. Omidi
Abstract
Drought stress affects the morphology, physiology, and biochemistry of plants and will have major effects on agricultural production. This study was conducted to evaluate the effect of drought on some physiological and grain yield properties of Balangu populations (Lallemantia royleana Benth.), in the ...
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Drought stress affects the morphology, physiology, and biochemistry of plants and will have major effects on agricultural production. This study was conducted to evaluate the effect of drought on some physiological and grain yield properties of Balangu populations (Lallemantia royleana Benth.), in the Research Station of Shahed University. This study was conducted in a split-plot design based on randomized complete block design (RCBD) with three replications during 2014-2015. The experimental factors consisted of three different levels of drought stress at the flowering stage as main factors (applying soil water potential of -0.5, -6.5 and -9.5 atm), and Balangu populations including one population from Kurdistan and four populations from Esfahan province (Esfahan3, Esfahan5, Esfahan6, Esfahann) were considered as subplots. The traits studied included grain yield, one thousand seed weight, photosynthetic pigments content, proline content, total phenol content, membrane stability index (MDA), and peroxidase activity. According to the results, drought stress had significant effects on all traits except chlorophyll b content and chlorophyll a/b ratio. Population and its interactions showed a significant effect with all traits except anthocyanin content. Drought caused to the reduced content of photosynthetic pigments, membrane stability index, thousand grain weight and grain yield. With increasing drought stress, the lipid peroxidation enzymatic activity and non-enzymatic antioxidants such as phenolic content, carotenoids content, anthocyanins content, and proline content of tissue increased to induce drought tolerance. The highest grain yield with the mean of (312.77 kg/ha) and the highest phenolic content with an average of (14.02 mg/g FW) were recorded for the Esfahan3 population under relatively severe stress.
K. Babaee; M. Amini Dehaghi; S.A.M. Modares Sanavi; R. Jabbari
Abstract
Water deficit stress, permanent or temporary, limits the growth and the distribution of natural vegetation and the performance of cultivated plants more than any other environmental factors. Mechanism involved is still not clear. Thyme (Thymus vulgaris L.) is an important medicinal plant in perfume and ...
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Water deficit stress, permanent or temporary, limits the growth and the distribution of natural vegetation and the performance of cultivated plants more than any other environmental factors. Mechanism involved is still not clear. Thyme (Thymus vulgaris L.) is an important medicinal plant in perfume and medical industry. In this research, the effects of water deficit stress on growth, yield, metabolites compatible (prolin) and oil composition of thyme (thymol) were studied. Complete randomized block design with 4 treatments and 4 replications have been used in 2006. Water deficit levels included control (100% field capacity), mild stress (85% field capacity), medium stress (70% field capacity) and severe stress (55% field capacity). The statistical analysis showed that water deficit had significant effect on growth parameters, yield biomass, prolin and thymol. Water stress decreased plant height, number of secondary branches, dry and fresh weight growth and root mass, dry and fresh weight root and length root. In addition, thymol percentage and prolin content increased with severe stress (55% field capacity). Morphological yield with secondary metabolites prolin and thymol were obversed with water deficit changes.
