EFFECT OF VESICULAR-ARBUSCULAR MYCORRHIZAE ON METABOLISM OF MOONG PLANTS UNDER NACL SALINITY

In a pot experiment, the effect of NaCl salinity (control-S0, 12.5 mM NaCl-S1 and 25 mM NaCl-S2) in the presence and absence of mycorrhizal inoculation was studied on plant metabolism at 40 (pre-flowering-PF) a nd 62 (flowering-F) days after sowing (DAS) on moong (cv. ML-131) plan ts. The response of salinity to various parameters varied with growth stages. Leaf nitrate reductase activity (NR, EC 1.6.6.1) was greater i n mycorrhizal (M) plants at S2 level but nitrogenase activity (N2ase, EC 1.18.2.1) was similar in the two types of plant. Proline accumulati on was greater in M plants at S1 level at both growth stages while it was only so at S2 levels at the PF stage while only at S2 level at F. The concentration of total sugars was greater with M plants at S2 leve l at both growth stages while it was so for total N only at F. There w as greater Mn concentration in M plants at both salt levels and at bot h the growth stages while it was so, only for K, Zn and Fe at S1 level at PF. Similar concentrations of K and Na were observed in mycorrhiza l and non-mycorrhizal plants at S2 level at both growth stages. These results suggest that, in general, the mycorrhizal inoculation has bene ficial effect on plant metabolism under NaCl salinity in moong plants.