Showing 4 results for Osmotic Adjustment
Miss. Sanaz Sarrafi, Mr. Arman Azari, Mr. Rouhollah Saberi Riseh, Mr. Ali Akbar Mohammadi Mirik,
Volume 7, Issue 2 (8-2017)
Abstract
To study the effect of bacterial siderophore on the second crop of maize (SC645) under drought stress conditions, a split-factorial experiment, arranged in a randomized complete block design with three replications was conducted in Faculty of Agriculture, Vali-e-Asr University of Rafsanjan at summer 2014. Sampling time was considered as main factor. Five samplings were performed after imposing the irrigation treatments. The factorial combination of two irrigation intervals (75 (unstressed control) and 120 mm evaporation from Class-A pan) and two siderophore application treatments (with and without application) were considered as sub factors. The foliar application of siderophore (2000 mg l-1) was applied two times. In addition, 20 kg siderophore ha-1 was applied with irrigation. The chl a, b and carotenoids decreased with delay in irrigation while increased with siderophore application in each irrigation. Also, proline, soluble sugars and sucrose accumulated with increasing irrigation intervals and delay in irrigation. Increase in intervals and delay in irrigation without siderophore application resulted in an increase in membrane lipid peroxidation. The trend of changes in traits was significantly influenced by the availability of soil moisture, and modifications in the above-mentioned trait values were observed with delays in irrigation. Irrigating (rewatering) of plants subjected to water deficit stress did not improve their traits values compared with the unstressed control, indicating that short-term effects of drought would not recover by irrigation. Bacterial siderophore enhances the ability of osmotic adjustment and photosynthetic capacity and is effective in ameliorating the harmful effects of drought
M. Heidari, H. Nadeyan, A.m. Bakhshandeh, Kh. Alemisaeid, G. Fathi,
Volume 11, Issue 40 (7-2007)
Abstract
The influence of Nitrogen (N) rates on mineral nutrient uptake in stem and seeds, proline and carbohydrate in flag leaves of Wheat (Triticum aestivum L . Var Chamran) under saline conditions was studied in a field experiment in 2003 and 2004. The experiment was conducted using a split plot design with three replications. The treatments comprised five levels of salinity: 1.5, 5, 10, 15 and 20 ds/m in main plot and three nitrogen levels: 50 , 100 and 150 kg N/ha in sub plot. Salinity treatments were applied in a clay–loam soil by water with NaCl and CaCl2 (5:1 by wt ). The results showed, the nutrient uptake was influenced by both salinity and N treatments. With the Exception of magnesium in seed, salinity increased nitrogen, calcium and magnesium concentrations in seed and stem in both years. By increasing salinity levels, the concentration of potassium in stem and seed decreased and Sodium concentration increased. In the stem the concentration of Sodium in the 20 ds/m was about 17 and 22 times more in the first and second year, respectively. In these experiments, by increasing salinity and nitrogen treatments, proline concentration in flag leaves increased in the two stages (flowering and milky stages) in both years. Salinity had similar effect on carbohydrate accumulation in both stages, but nitrogen treatment had two different effects on carohydrate concentration. In flowering stage, by increasing nitrogen application, carohydrate concentration increased but in milky stage decreased.
S Bazi, M Haydari, N Mehdinejad, F Abasi,
Volume 12, Issue 46 (1-2009)
Abstract
To evaluate effects of different salinity levels on activity of antioxidant enzymes (CAT, APX and GPX) and osmotic components (carbohydrate and proline) in two sorghum genotypes, an experiment was conducted as completely randomized factorial design with three replications in Zabol university in 2007. Three levels of salinity control (0), 100 and 200 mM NaCl and two sorghum genotypes (Payam and Sistan) were compared. Results showed that by increasing salinity levels from 0 to 200 mM NaCl, the activities of these three antioxidant enzymes were significantly increased and the highest level of activity was observed in 200 mM salinity. Payam cultivar had the highest level of APX and GPX enzyme activity in these experiments. salinity significantly changed two osmotic adjustment concentrations (Carbohydrate and proline) and increased their concentrations. The highest proline and carbohydrate were showN in Sistan and Payam, respectively. In this study we found positive correlation between osmotic components and antioxidant enzyme activity. The results showed that in these two sorghum cultivars the two mechanisms help with salinity tolerance. A direct relationship between activity of the antioxidant- enzymes and accumulation of osmotic regulators (carbohydrate and proline) was observed. In Payam genotype, as the activity of the enzymes and accumulation of osmotic regulators increased, the weight of the plants decreased. The decrease in weight could mean some of plant energy is allocated to the production of antioxidant enzymes and osmotic regulators.
M Babaeian, M Haydari, A Ghanbari,
Volume 12, Issue 46 (1-2009)
Abstract
In order to study the effects of foliar micronutrient application under water stress at three stages of growth on proline and carbohydrate concentrations, grain yield and yield components of sunflower (Alster cultivar), a field experiment in split plot design with three replications was conducted in 2007. Alster cultivar was considered under water stress at three stages of growth (heading, flowering and grain filling) as main plot and seven micronutrient treatments, Fe, Zn, Mn, Fe+Zn, Fe+Mn, Zn+Mn and Fe+Zn+Mn, as sub plots. Results showed, water stress at three stages of growth significantly decreased grain yield, biological yield, 1000 weight seeds, cap diameter and cap weight of sunflower (Alster cultivar). The impact of water stress was more pronounced when applied at grain filling. Use of foliar micronutrient increased grain yield in water stress. On the other hand, use of Mn foliar application had the highest positive effect on yield components and grain yield. Free proline and total soluble carbohydrate concentration were increased under water stress at all of the three stages of growth. The highest concentration of these two components was found on the flowering stage. Foliar micronutrient also increased accumulation of the two components.
