RECENT ADVANCES IN SYMBIOTIC NITROGEN FIXATION OF TREE LEGUMES Effect of pH on nodulation of soybean rhizobia from Weifang and Huayuankou soils The competitiveness of Bradyrhizobium sp. (Arachis) studied by using luxAB marker gene technique Effects of inoculations of Glomus mosseae and/or Bradyrhizobium japonicum on formation and distribution of nodules and phosphorus uptake of soybean Study the effects of Mo and inoculation of Bradyrhizobium in acid purple soil by celB gene maker Effect of Rhizobia and PGPR co-inoculant on soybean characteristics and soil enzyme activities