Effects of inoculation with stress-adapted arbuscular mycorrhizal fungus<i>Glomus deserticola</i>on growth of<i>Solanum melogena</i>L. and<i>Sorghum sudanese</i>Staph. seedlings under salinity and heavy metal stress conditions

Abstract

The beneficial effects of a Glomus deserticola strain isolated from the rhizosphere of grasses (belonging to Poaceae family) growing along the industrial waste from a distillery were investigated under stress conditions. The study was conducted to assess the efficacy of the arbuscular mycorrhizal (AM) fungal ecotype in salinity and heavy metal (HM) tolerance of eggplant (Solanum melongena L.) in soils amended with various stress levels of NaCl, zinc and cadmium. Mycorrhizal (M) seedlings produced a significantly (p < 0.05) greater growth response and were more tolerant to salt and HM stresses than nonmycorrhizal (NM) seedlings in all treatments. The HM contents in the plant tissues were significantly higher in M than NM eggplants. Furthermore, when the efficacy was compared with other AM isolates in HM-polluted soils with Sudan grass (Sorghum sudanese Staph.) as a test plant, the AM ecotype responded best to these soils, as evident from the significantly greater growth response and its aggressiveness in colonizing roots in all soil types tested. These results suggest that this G. deserticola ecotype can be used as an effective tool to alleviate the adverse effects of excessive salinity and HM toxicity on plant growth. Finally, the isolate may have potential in the bioremediation of polluted soils.