To fix up the physio-chemical bases of tolerance in polyembryonic mango rootstock under salt stress

Abstract

Polyembryonic mango (Mangifera indica L.) rootstocks, ‘Kurukkan’ and ‘Olour’ were irrigated with tap water containing 0, 50 and 100 mM NaCl at four days interval for 40 days. NaCl stress reduced net photosynthetic rate (Pn), stomatal conductance (Cs), trehalose and phenol content in both rootstocks. However, increased the activities of peroxidase (POX), catalase (CAT), superoxide dismutase (SOD), membrane injury index (MII), proline content, total soluble sugar content, in plant tissues compared to what occurred in plants in the absence of NaCl. Salt tolerance mechanism in ‘Olour’ may be due to higher POX and CAT activities, higher proline and phenol content, lower MII and lower leaf abscission and also higher root Cl- content in plant tissues while ‘Kurukkan’ could tolerate high NaCl concentration by maintaining higher net photosynthetic rate and stomatal conductance, higher SOD activity, higher sugar and trehalose content, higher accumulation of root Na+ in plants. Hence, based on the results it could be said that salt tolerant mechanism occur in both the rootstocks.