Morphological and biochemical response of eight pomegranate (Punica granatum L.) cultivars under salinity stress

Abstract

Purpose: Identification of pomegranate cultivars with higher tolerance to salinity stress was the purpose of the current study. Research Method: One-year-old rooted cuttings of the pomegranate cultivars including 'Malase Saveh' ('M-Saveh'), 'Malase Isfahan' ('M-Isfahan'), 'Robabe Ghermeze Shiraz' ('Robab'), 'Gabrie Yazd' ('G-Yazd'), Gabrie Torshe Yazd' ('GT-Yazd'), 'Zaghe Sefide Yazd' ('ZS-Yazd'), 'Zaghe Torshe Yazd' ('ZT-Yazd') and 'Malase Torshe Pishva' ('M-Pishva') were cultured in plastic pots and treated with different concentrations of sodium chloride in irrigation water including 0 (control), 3, 6, 9 and 12 dS m-1. Findings: At 12 dS m-1salinity level, the lowest decrease in plant height was observed in 'Robab', and 'M-Pishva' and the lowest decrease in the plant diameter was recorded in 'ZT-Yazd' and 'G-Yazd'. At the same salinity level, 'GT-Yazd' showed the lowest percentage of increase in electrolyte leakage (EL) compared to the control (23%). The highest increase in proline content was observed at 9 dS m-1 salinity for 'ZS-Yazd' and at 12 dS m-1 salinity for 'GT-Yazd'. At high salinity levels, leaf chlorophyll content decreased in pomegranate cultivars compared to the control. The activity of peroxidase enzyme in 'M- Pishva', ZT-Yazd' and 'GT-Yazd' followed an increasing and then decreasing with increasing salinity levels. The activity of the superoxide dismutase enzyme was highest in 'G-Yazd', 'M-Isfahan' and 'Robab'. Limitations: Investigation of salinity tolerance in pots is one of the limitations of this study. Originality/Value: Yazd cultivars including 'G-Yazd', 'GT-Yazd', 'ZS-Yazd' and 'ZT-Yazd' were more tolerant to salinity stress.

Keywords

• antioxidant enzymes
• chlorophyll
• electrolyte leakage
• proline
• salt stress