J. Bio. Env. Sci.5(6), 179-183, December 2014
Horse gram [Macrotyloma uniflorum (Lam.) Verdc. = Dolichos biflorus (Linn.)] is an important pulse crop and it is extensively cultivated on light red and gravel soils of peninsular India. It derives its importance from its adaptability to poor and adverse climatic conditions which are unsuitable for other pulse crops. Salt tolerant rhizobia are useful in improving the condition of disturbed and extreme climatic conditions. The rhizobia associated with horse gram were found to be highly salt tolerant and these rhizobia also showed tolerance to other salts like chlorides, sulphates and carbonates of sodium, potassium, manganese, calcium and magnesium. Therefore the present study was undertaken to investigate the influence of salt concentration on phosphate solubilization. Solubilization of tricalcium phosphate by salt tolerant strains of Rhizobium from horse gram was investigated. Out of 32 strains of Rhizobium, six strains were found to be efficient phosphate solubilizers at various salt concentrations. These strains showed maximum phosphate solubilization at 0.2M, 0.4M, and even at 1M salt concentration. These strains can be exploited for phosphate solubilization under salt stress.
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