A. Abdollahi Arpanahi; M. Feizian; Gh. Mehdipourian
Abstract
To investigate the effects of plant growth promoting rhizobacteria (PGPR) and drought stress on essential oil of Thymus daenensis Clack, a greenhouse experiment was conducted in Shahrekord, Iran in 2017. The experiment was arranged as a factorial in a completely randomized design with three replications. ...
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To investigate the effects of plant growth promoting rhizobacteria (PGPR) and drought stress on essential oil of Thymus daenensis Clack, a greenhouse experiment was conducted in Shahrekord, Iran in 2017. The experiment was arranged as a factorial in a completely randomized design with three replications. The first factor included four levels of irrigation: well-watered (No stress), irrigation after depletion of 20-25% of field capacity (FC) (Low stress), irrigation after depletion of 35-40% of FC (Mild stress) and irrigation after depletion of 55-60% of FC (Severe stress). The second factor included two levels of PGPR treatments: no inoculation (Control) and inoculation with PGPR. The results showed that the morphological parameters were significantly increased in PGPR treatments, while water stress decreased all parameters. The essential oil amount increased in low stress and decreased in severe stress. PGPR inoculation increased the amount of essential oil, although this increase was not statistically significant. PGPR incubation and drought stress had a significant effect on 13 and 14 components, respectively. The interaction of PGPR and drought stress had a significant effect on the oil components. Thymol and carvacrol, two important components of T. daenensis essential oil, decreased with increasing severity of drought stress, but PGPR inoculation increased them, especially at drought stress treatments.
Kh. Azizi; J. Nazari Alam; Mohammad Feizian; R. Heydari
Abstract
This study was aimed to evaluate the quantitative and qualitative performance of different populations of Milk Thistle (Silybum marianum L.( under the influence of autumn and spring planting season. Therefore, a split plot experiment was conducted including autumn and spring planting as main plots and ...
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This study was aimed to evaluate the quantitative and qualitative performance of different populations of Milk Thistle (Silybum marianum L.( under the influence of autumn and spring planting season. Therefore, a split plot experiment was conducted including autumn and spring planting as main plots and four local populations (Shush, Poldoktar, Khoram Abad and Aleshtar) and a crop cultivar as sub plots. The study was carried out in the Faculty of Agriculture, Lorestan University, for two years 2014-2015. In addition, the native and crop populations of this species in Aleshtar were compared in a randomized complete block design. Based on the results, there was a significant difference between spring and autumn planting seasons. The highest plant height (107 cm), capitol diameter (44 mm), number of grains in capitol (78) and grain yield (1000 kg ha-1) were obtained in autumn planting. The interaction effect of planting season and population type showed that the highest content of silymarin (22 mg/g of dry weight) and silybin (3.9 mg /g of dry weight) was obtained from the crop cultivar in autumn planting. The comparison between native and crop populations in Aleshtar region showed that the highest content of silybin (4.2 mg /g of dry weight) and silymarin (more than 21 mg / g of dry weight) was recorded for native Aleshtar population compared with other populations. In general, it was determined that the highest and lowest quantitative and qualitative performance of Milk Thistle in the temperate region of Khorramabad was obtained in autumn planting, and the highest content of silymarin and silybin was recorded for the native Aleshtar population compared with other populations.