ENHANCED EFFICIENCY OF SYMBIOTIC NITROGEN-FIXATION BY A DERIVATIVE OF RHIZOBIUM-MELILOTI

The derivative of Rhizobium meliloti Bp, that had just been used as inoculant strain was isolated and characterized. The symbiotic efficiency of the derivative Bp 17 was compared with the parental Bp strain in laboratory and field conditions. In both kinds of experiments the increase of the yield of plants was higher in the case of Bp 17 strain. In field experiment that had been conducted during 3 years the total green mass of plants infected with Bp 17 was about 10% higher than the total green mass of plants inoculated with the parental strain. Rhizobium meliloti Bp 17 formed nodules earlier than its parental strain and occupied more than half of nodules even in the ratio Bp/Bp 17 = 10:1.