Response of rhizobium to spent engine-oil contamination in the rhizosphere of legumes (arachis hypogaea and phaseolus vulgaris)‎

الملخص EN

Indiscriminate releases of spent-engine oil into the environment mean danger to legume nodulation activities by rhizobium.

to ascertain this, responses of rhizobium to spent engine-oil in the rhizosphere of A.

hypogaea and P.

vulgaris were studied by growing viable seeds in spent engine-oil contaminated soil at 0, 1.0 and 3.0 % w/w for 120 days.

the influence of oil on total populations of heterotrophs and rhizobium in rhizosphere and nodule were estimated by the soil dilution plate method on nutrient agar (NA) and yeast extract mannitol agar (YEMA), respectively.

plant height and root growth were assessed using a graduated-meter rule nodule and pod numbers by counting.

results showed that the population of rhizobium in rhizosphere and nodule decreased with increased oil concentrations.

results were in contrast to observed increases in bacterial heterotrophs for tested legumes (P<0.05).

plant height, root length, nodule and pod formation decreased with increased oil concentrations in soil (P<0.05).

spent engine-oil impeded the Rhizobium response in the rhizosphere of legumes.