Identification and effectiveness of rhizobial strains that nodulate Lupinus polyphyllus

Abstract

Abstract Lupinus polyphyllus plants were heavily nodulated at 10 field sites sampled across the South Island. Twenty-two bacterial isolates from these nodules formed functional nodules on L. polyphyllus indicating that rhizobia that nodulate L. polyphyllus were present across a wide range of sites in the South Island. Gene sequences identified all 22 isolates and the Group G commercial inoculant as Bradyrhizobium. Eleven isolates and the Group G inoculant were tested for their effectiveness on growth of L. polyphyllus plants in a high country soil in a glasshouse. All plants nodulated regardless of inoculum treatment but there was variability in effectiveness. This suggests that it may be beneficial to use a rhizobial inoculant for high country soils, but further work is required before a recommendation can be made. Keywords: nitrogen fixation, perennial lupin, Lupinus polyphyllus