A Qualitative Survey of Nodulating Ability of Legumes of Pakistan

Abstract

The present report nodulation survey of 115 legumes out of which 20 belonged to caesalpiniaceae, 16 belonged to mimosaceae and 79 belonged to Papilionaceae. Percentage of nodulation in caesalpiniaceae, mimosaceae and Papilionaceae was found 0.0%, 94.1%, and 100%, respectively; the shape colour and size of the nodules were recorded. Rhizobial isolates from nodules of 47 legumes were obtained in pure culture. The isolates were characterized on the basis of their morphological and biochemical reactions. Their antibiotic sensitivity against some antibiotics was also studied. Cross inoculation experiments between some legumes of agriculture importance and few isolates from wild legumes were also made. Total nitrogen contents of 113 out of 115 leguminous plants were estimated. This data provided an indirect evaluation of high dinitrogen fixing Rhizobial strains. The texture and PH of the soil collected from the rhizosphere of the legumes surveyed was also determined. Relationship of soil PH and soil type with frequency of nodules/amount of nitrogen fixed were also evaluated.