Biochemical and salt ion uptake responses of seven mango (Mangifera indica L.) rootstocks to NaCl stress.
Pandey P., Singh A. K., Dubey A. K., Dahuja A.
Author Affiliation: Division of Fruits and Horticultural Technology, Indian Agricultural Research Institute, Pusa Campus, New Delhi - 110 012, India.
Journal of Horticultural Science and Biotechnology 89 : 367-372
Abstract : Uniform-sized, 6-month-old seedlings of seven mango (Mangifera indica L.) rootstocks ('Moovandan', 'Bappakai', 'Nekkare', 'Kurukkan', 'Olour', 'Terpentine', and 'Chandrakaran') were irrigated with tap water containing 0, 50, 100, or 150 mM NaCl at 4 d intervals for 40 d. NaCl stress increased the activities of peroxidase (POX), catalase (CAT), and superoxide dismutase (SOD), and the concentrations of malondialdehyde (MDA), proline, and trehalose. The highest anti-oxidant enzyme activities were observed in the rootstocks 'Olour', 'Bappakai' and 'Terpentine' at the highest level of salinity (150 mM NaCl). Leaf proline concentrations increased most in 'Olour', 'Kurukkan', and 'Terpentine' with increasing levels of salinity. The concentration of Na+ ions in leaf tissues increased to a maximum (123.5%) of the respective (0 mM NaCl) control in 'Chandrakaran', while 'Bappakai' had the highest Na+ ion concentration in root tissues at the highest level of salinity (77.3%) compared to the respective control. Compared to the respective controls, the maximum increase (109.1%) in leaf Cl- ion concentration was recorded in 'Moovandan', while 'Chandrakaran' had the highest concentration of Cl- ions (139.3%) in its root tissues when irrigated with water containing 150 mM NaCl. Our results suggest that the salt-tolerant behaviour of the mango rootstocks 'Olour' and 'Terpentine' may be due to their ability to inhibit the uptake of Cl- and Na+ ions, combined with higher accumulations of proline. These two rootstocks may therefore be used to improve the yield and quality of commercial mango cultivars grown in salt-affected areas.