XVI International Botanical Congess

Amorpha nitens C. Boynt., an endangered leguminous shrub, A. fruticosa L., A. canescens Pursh, and A. nana Nutt. were propagated from seeds stratified for 10 days at 5?C in sterile-moist conditions. Fifteen days after stratification, 86% of the A. nitens seeds exposed to light germinated and only 40% of the seeds germinated in pots filled with vermiculite. Between 95% and 100% of the seeds of A. nana, A. canescens, and A. fruticosa germinated at day 9 under light. Rhizobia strains were isolated from root nodules of A. nitens plants in southern Illinois. Ninety days after inoculation, nodulation on A. nitens seedlings was different among strains. Seedlings averaged 34 to 55 nodules with no nodules on non-inoculated seedlings. No differences were observed for shoot growth. Strains were also tested for symbiotic promiscuity on A. canescens, A. fruticosa, and A. nana. These species showed differences in nodulation depending on the rhizobial strain, however, there were no consistent patterns among the strains on the four species.