Document Type : Full Paper
Authors
1
Assistant Professor, Department of Horticultural Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran.
2
Professor, Department of Horticultural Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran
3
Assistant Professor, Department of Horticultural Science, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran
4
Assistant Professor, Department of Plant Production Engineering and Genetics, Faculty of Agriculture, Shahid Chamran University of Ahvaz, Ahvaz, Iran
Abstract
Citrus rootstocks play a key role in growth and resistance to abiotic stresses such as salinity and alkalinity. . Therefore, to investigate the resistance of two citrus rootstocks, sour orange and Volkameriana, to stress conditions, a factorial experiment was conducted in a completely randomized design with 4 replication in the greenhouse of the Faculty of Agriculture, Shahid Chamran University, Ahvaz. In this experiment, the effect of four concentrations of 0, 30, 60, and 90 mM sodium chloride and two pH levels (6.5 and 8.2) was investigated on some morpho-physiological and biochemical characteristics of two citrus rootstocks, sour orange and Volkameriana,. The results showed that in both sour orange and Volkameriana rootstocks, increasing salinity concentration significantly reduced shoot fresh and dry weight, root dry weight, photosynthesis, transpiration and relative water content at both pH level,. pH 8.2 with 90 mM NaCl reduced photosynthesis by 51.83% in sour orange and by 57.5% in Volkameriana rootstock compared to the control. Also, stress conditions significantly reduced chlorophyll content and increased ion leakage, proline and carbohydrates. The highest proline content (23.02 μmol/g fresh weight) was obtained in the sour orange rootstock with pH 8.2 and 60 mM NaCl and the highest carbohydrate content (29.89 mg/g f.w) was obtained in the Volkameriana Rootstock with pH 8.2 and 30 mM sodium chloride. In general, the sour orange rootstock with increased proline content, photosynthetic pigments, and gas exchange had higher tolerance to salinity and alkalinity stress conditions and had more morphological characteristics than Volkameriana
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