MADRAS AGRICULTURAL JOURNAL

Effect of Salt Stress on Antioxidant Enzyme Activities and Nutrient Ion Concentrations in Mango Rootstocks

Abstract

                                A pot culture experiment was conducted during 2015 – 2016 at the College Orchard, TNAU, Coimbatore for identification of salt-tolerant rootstocks in mango. The experiment was carried out with two factors (rootstocks and salinity levels) under Completely Randomized Design and replicated thrice. The mango rootstocks viz., Alphonso, Banganapalli, Sendhuram, Neelum and Bangalora were used and three different levels of salt concentration (25 mM NaCl, 50 mM NaCl and 75 mM NaCl) along with control were imposed. The salinity levels were imposed to the seedlings grown in polybags up to 90 days at an interval of 2 -3 days depending upon moisture availability. Alphonso rootstock registered the highest values of catalase and peroxidase (10.03 μg H2 O2 g-1 min-1 and 1.34 change in OD at 430 nm min-1 g-1 respectively) followed by Neelum at 75 mM NaCl salinity level. Higher accumulation of K+ ions in leaf (0.72 %) and root (1.21 %) were registered by Alphonso rootstock at 75 mM NaCl. The accumulation of Na+ ions which is supposed to be harmful, was found to be more in leaf (0.39 %) and root (0.41 %) tissues of Bangalora rootstocks at 75 mM NaCl whereas the same was found to be the least in leaf (0.23 %) and root (0.25 %) tissues of Alphonso rootstocks. Based on the antioxidant enzyme activities and nutrient ion concentrations it is concluded that Alphonso rootstocks were found to be the best among the rootstocks studied followed by Neelum under salinity stress

Key words : : Catalase, Peroxidase, Potassium, Sodium, Alphonso mango.