Study on the interaction of Heterodera glycines and the symbiotic bacterium,Bradyrhizobium japonicum on susceptible and resistant soybean cultivars

The interaction of the soybean cyst nematode, Heterodera glycines Hg Type 0 and Bradyrhizobium japonicum were studied on two resistant and susceptible soybean cultivars, DPX and JK respectively under sterilized soil and natural infested field soil. Data of plant growth parameters, number and weight of nodules, number of cyst, second stage juveniles and eggs and reproduction factor were recorded. The results showed in both experiments soybean cyst nematode was reproduced well on susceptible cultivar JK. B. japonicum was able to produce nodulation on both cultivars, the inoculated treatments with Rhzobium showed significant difference on growth parameters compared to non-inoculated treatments in both cultivars. H. glycines Hg Type 0 (race 3) caused significant decrease on bacterial growth parameters and plant growth factors, in all combinations of B. japonicum and SCN. In high population densities of soybean cyst nematode soybean plants not only are affected by the nematode but also the bacterial growth parameters are influenced by the nematode that enhances the nematode damage.