Tolerance to Mn and Al by soybean rhizobacteria

The tolerance to Mn2+ & Al3+ was measured in 164 strains of rhizosphere bac teria obtained from the roots of two soybean varieties (Glycine mar L. Merr ill, var Tancacha and Glycine max L. Merrill var UFV1). Strains were tested on TSA-10% supplemented with 0,06; 0,6; 0,9 or 1,1 mM I-1 of Mn2+ and 0,07 ; 0,4; 1,1 of 1,5 mM I-1 of Al3+. Mn2+ did not affect the viability of stra ins. The highest concentration of Al3+ (1,5mM) showed an adverse effect of 12% on Tancacha variety and 30% on UFV1.