Investigation of different bacteria Bradyrhizobium japonicum inoculation on soybean seeds quality and quantity (Glycine max (L.) Merr.)

Inoculant of Bradyrhizobium japonicum bacteria is one of the important factors affecting soybean seed’s oil and protein contents. To study the effects of bacterial strains on soybean seeds quality (oil and protein) and quantity (seed yield) an experiment was carried out during 2000-2001 at research field of soybean in Sari. A split plot arrangement of treatments in a completely randomized block design was used with four replications. The treatments were consisted of three bacterial strains (Helynitro، Soyar and Abokhak) and four soybean cultivars (Hill، Sahar، J/k and B/P) and control plots (seeds without inoculants). Seed quality (oil and protein)، yield، number and dry weight of nodules per plant were measured. Bacterial strains did not show significant effect on traits، but the results mentioned that cultivars had significant effects on almost of traits. In fact، the interaction effects of J/K with Helynitro strain produced the highest seed، oil and protein yields. Cultivar J/K and Hill in control plots had the highest seed oil and protein percentages respectively. The maximum number of nodules per plant was obtained in J/K with Abokhak. Contrast to other cultivars Sahar produced the highest nodule dry weight with all bacterial strains.