Document Type : Original Article
Authors
1 Assistant Professor. Agronomy and Plant Breeding Dept., University of Zabol
2 . B.Sc of Agricultural Biotechnology Institute, University of Zabol
Abstract
Drought stress is one of the most important environmental factors in reducing growth, development and production of plants. To evaluate the effect of different salinity levels on antioxidant enzymatic activity (CAT, APX and GPX), sodium and potassium uptake and two organic compounds (carbohydrate and proline) in six wheat cultivars at seedling stage, a factorial experiment based on CRD was conducted with three replications at Biosynthesis Research Centre of Zabol University in 2007. The treatments were salinity at four concentrations including 0, 100, 200 and 300 mM NaCl and six wheat cultivars (Alvand, Falat, Gaskojen, Line4, Mahdavi and Shirazi). Results showed that increasing salinity level from 0 to 300 mM NaCl significantly increased the activity of only APX antioxidant enzyme, while decreased the activity of the two other antioxidant enzymes. Among the cultivars, Falat and Mahdavi had the highest level of APX activity at 300mM salinity level. Increased salinity levels enhanced carbohydrate and proline concentrations in all six cultivars. Among the cultivars, Alvand, Gaskojen, Lain4 and Shirazi which had the lowest APX enzyme activity, showed the highest carbohydrate and proline concentrations. Salinity caused reduction in potassium and an increase in sodium uptake. Falat and Mahdavi cultivars had the best controlling on sodium and potassium uptake due to possessing the highest APX activity as well as a desirable carbohydrate and proline content in aboveground parts especially at S3 salinity level. From the results of this study it can be deduced that osmotic adjustment is more effective in conferring the salinity tolerance to wheat cultivars than the antioxidant enzyme activity at seedling stage.
Keywords
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