Mycorrhizal status of the endangered species Astragalus applegatei Peck as determined from a soil bioassay

Abstract

The mycorrhizal status of Astragalus applegatei Peck is reported for the first time on plants from a greenhouse soil bioassay. Seedlings were grown in a potting mix inoculated with soil collected near A. applegatei plants in nature. Plants were also grown in non-inoculated potting mix. Only plants from the native soil inoculation survived. Abundant colonization of VAM fungi was found in all 15 plants analyzed from the native soil treatment, and chlamydospores produced by Glomus spp. were observed. Mycorrhizal colonization was estimated to be 23% of total fine root length after 6 weeks and 53% after 14 weeks. Our results provide ecologically important information for conservation and restoration efforts underway to recover populations of this endangered species.