Determination of the natural Rhizobium populations in soil of Elazığ region

The soil samples were collected from different regions of Elazığ province and its districts. In these regions, the lentil and bean are mostly cultivated. The soil samples were obtained from the same regions in both spring and autumn season twice in a year and twenty bacteria strain were isolated. The study had been carried out in greenhouse, Rhizobium populations of soil were determined with plant infection method and most probable number tables. In one gram of the soil samples taken from lentil cultivated fields were investigated and number of Rhizobium leguminosarum bv.viciae were found to be 9-xlO1 - 9,19x10". In the soil samples from bean, cultivated fields population of R.phaseoli were found to be 4,2xl02 - 9,19xl04 in number The lentil and bean plants grown in greenhouse and inoculated withIV soil samples had been harvested after four weeks and their nodule numbers, colour, dry weight of upper parts of the plant had been determined. In addition, some cultural and biochemical properties of the isolated bacteria strains from nodule on the plant root were determined. Dry weight values of lentil in spring and autumn season were found as 0,510 - 0,280 g and 0,407 - 0,267 g respectively. For the bean, these values were faund as 2,162 - 1,866 g and 3,893 - 1,624 g in the spring and autumn season respectively. Nitrogen contents were determined as % Nitrogen by using Kjeldahl method. These values, in the lentils belonging to spring and autumn season were 4,11 - 3,29 % and 4,04 - 2,98 % and in the beans 2,34 -1,84 % and 2,46 - 1,96 % respectively. Dry weight % Nitrogen and total nitrogen amounts were calculated by using varians analysis. Significant levels of the Rhizobium strains according to nitrogenous, nonnitrogenaus and positive controle were compared by Duncan test. Comprasing of the seasons were carried out by Mann Whitney Utest. Simbiotic effectives of the natural Rhizobium populations in the soil were determined essentially dry weight of plants. As a result 20 % of the lentil bacteria found to be most effective, 40 % effective and the rest 40 % middle effective. While 30 % of the bean bacteria were faund as middle effective and the rest 70 % were lower effective. Key words: Rhizobium leguminosarum bv.viciae, R.phaseoli, Lens culinaris, Phaseolus vulgaris Most probable number, Plant Infection Method.