The ameliorative effect of fulvic acid(0, 300, and 600 mg L-1) on photosystem II and antioxidant enzyme activity of the rapeseed(Brassica napus L.) plant under water stress(60, 100, and 140 mm evaporation from class A...The ameliorative effect of fulvic acid(0, 300, and 600 mg L-1) on photosystem II and antioxidant enzyme activity of the rapeseed(Brassica napus L.) plant under water stress(60, 100, and 140 mm evaporation from class A pan) was studied using split plots in a randomized complete block design with three replications. Results indicated that application of fulvic acid(FA) improved the maximum quantum efficiency of PSII(Fv/Fm)and performance index(PI) of plants under both well-watered and limited-water conditions. The time span from Foto Fmand the energy necessary for the closure of all reaction centers was significantly increased, but the size of the plastoquinone pool was reduced with increasing water stress levels. Plants treated with FA had higher peroxidase and catalase activities under all irrigation conditions. Activities of ascorbate peroxidase and superoxide dismutase in plants increased with increasing water stress. Malondialdehyde increased under severe water stress, but application of FA significantly decreased lipid peroxidation. Production of reactive oxygen species(ROS) is a common phenomenon in plants under stress. Under this condition, the balance between the production of ROS and the quenching activity of antioxidants is upset, often resulting in oxidative damage. In this study, application of FA significantly increased fluorescence of chlorophyll a, inhibiting ROS production and enhancing antioxidant enzymes activity that destroyed ROS. Thus, ROS in plant cells was reduced under water stress by application of FA and consequently lipid peroxidation was reduced.展开更多
Getting aware of one kind of soil surface attributs is very important. Assessment of important attributes of soil and vegetation can help us to be aware of rangeland potential and help us to determine its situation. T...Getting aware of one kind of soil surface attributs is very important. Assessment of important attributes of soil and vegetation can help us to be aware of rangeland potential and help us to determine its situation. The goal of this research is to determine some plant and soil indicators of hilly winter rangelands of Eastern and Southern slopes of Chaharbagh region in Golestan province. By considering plant cover and soil surface attributes, it used the SSCC （soil surface classification） method to assess soil surface attributes. The length and width of ecological patches were measured in the forms of lichen, lichen-Grass, forbs, shrub and bare soil inter patches with litter. Also in this research, it measured the 11 soil surface parameters. These parameters are belonging to three main soil attributes stability, infiltration and nutrient cycles. These three indicators were measured in east and west of Eastern and Southern slopes of this ecosystem and showed significance differences （p 〈 0.05） in shrub, forbs and lichen-grass. In southern and especially in west aspect, these indicators in shrub were more than Eastern. But, in lossy hill of Eastern, lichen-grass patch is more significant. The most important ecological indicators of east landscapes of this region are forbs and lichen-grass.展开更多
Essential oils chemical composition of,4rtemisia sieberi leaves/stems and flowers/fruits （F/F） growing wild in Kashan, central Iran, have been analyzed using GC-MS technique. This study was conducted in order to ide...Essential oils chemical composition of,4rtemisia sieberi leaves/stems and flowers/fruits （F/F） growing wild in Kashan, central Iran, have been analyzed using GC-MS technique. This study was conducted in order to identify and compare essential oil compounds in different aerial parts of Artemisia sieberi. Plants sampled at random in full flowering stage in a CR （completely randomized） design with three replications. Analysis on leaves/stems revealed 55 identified compounds, representing 97.66% of the oil with a-pinene being the main component （34.33%）; other significant components in the leaves/stems include： α-amorphene, β-pinene, δ-cadinene, α-cadinene, methyl cyclopentan. For flowers/fruits （F/F） 29 compounds were identified, representing 96.96% of the oil with the main component being α-amorphene （15.86%） and α-pinene （12.34%） being the second main component. A number of other significant components found in fiowers/fruits were α-campholene aldehyde, isopinocarveol, β-caryophylene, calarene, δ-cadinene. Several compounds （some with significant compositions） were found in this variety ofA. sieberi which are not reported in the previous literature.展开更多
文摘The ameliorative effect of fulvic acid(0, 300, and 600 mg L-1) on photosystem II and antioxidant enzyme activity of the rapeseed(Brassica napus L.) plant under water stress(60, 100, and 140 mm evaporation from class A pan) was studied using split plots in a randomized complete block design with three replications. Results indicated that application of fulvic acid(FA) improved the maximum quantum efficiency of PSII(Fv/Fm)and performance index(PI) of plants under both well-watered and limited-water conditions. The time span from Foto Fmand the energy necessary for the closure of all reaction centers was significantly increased, but the size of the plastoquinone pool was reduced with increasing water stress levels. Plants treated with FA had higher peroxidase and catalase activities under all irrigation conditions. Activities of ascorbate peroxidase and superoxide dismutase in plants increased with increasing water stress. Malondialdehyde increased under severe water stress, but application of FA significantly decreased lipid peroxidation. Production of reactive oxygen species(ROS) is a common phenomenon in plants under stress. Under this condition, the balance between the production of ROS and the quenching activity of antioxidants is upset, often resulting in oxidative damage. In this study, application of FA significantly increased fluorescence of chlorophyll a, inhibiting ROS production and enhancing antioxidant enzymes activity that destroyed ROS. Thus, ROS in plant cells was reduced under water stress by application of FA and consequently lipid peroxidation was reduced.
文摘Getting aware of one kind of soil surface attributs is very important. Assessment of important attributes of soil and vegetation can help us to be aware of rangeland potential and help us to determine its situation. The goal of this research is to determine some plant and soil indicators of hilly winter rangelands of Eastern and Southern slopes of Chaharbagh region in Golestan province. By considering plant cover and soil surface attributes, it used the SSCC （soil surface classification） method to assess soil surface attributes. The length and width of ecological patches were measured in the forms of lichen, lichen-Grass, forbs, shrub and bare soil inter patches with litter. Also in this research, it measured the 11 soil surface parameters. These parameters are belonging to three main soil attributes stability, infiltration and nutrient cycles. These three indicators were measured in east and west of Eastern and Southern slopes of this ecosystem and showed significance differences （p 〈 0.05） in shrub, forbs and lichen-grass. In southern and especially in west aspect, these indicators in shrub were more than Eastern. But, in lossy hill of Eastern, lichen-grass patch is more significant. The most important ecological indicators of east landscapes of this region are forbs and lichen-grass.
文摘Essential oils chemical composition of,4rtemisia sieberi leaves/stems and flowers/fruits （F/F） growing wild in Kashan, central Iran, have been analyzed using GC-MS technique. This study was conducted in order to identify and compare essential oil compounds in different aerial parts of Artemisia sieberi. Plants sampled at random in full flowering stage in a CR （completely randomized） design with three replications. Analysis on leaves/stems revealed 55 identified compounds, representing 97.66% of the oil with a-pinene being the main component （34.33%）; other significant components in the leaves/stems include： α-amorphene, β-pinene, δ-cadinene, α-cadinene, methyl cyclopentan. For flowers/fruits （F/F） 29 compounds were identified, representing 96.96% of the oil with the main component being α-amorphene （15.86%） and α-pinene （12.34%） being the second main component. A number of other significant components found in fiowers/fruits were α-campholene aldehyde, isopinocarveol, β-caryophylene, calarene, δ-cadinene. Several compounds （some with significant compositions） were found in this variety ofA. sieberi which are not reported in the previous literature.
