Microbial consortia inoculation of woody legume Erythrina brucei increases nodulation and shoot nitrogen and phosphorus under greenhouse conditions

Abstract

The legume-rhizobium symbiosis provides Nitrogen (N), while Legume-AMF symbiosis improves Phosphorus (P) supply to plants. This research was conducted to evaluate the symbiotic effectiveness of the Bradyrhizobium spp. and consortial inoculation of plant growth promoting bacteria -Bradyrhizobium shewense (AU27) and Acinetobacter soli (AU4), and arbuscular mycorrhizhal fungi Glomus sp.1 (AMF1) and Acaulospora sp.1 (AMF2), on growth, production and shoot N and P content of Erythrina brucei.The bacterial and mycorrhizal species were evaluated for phyto-beneficial properties in the greenhouse as individual as well as consortial inoculation.. All Bradyrhizobium species were effective for symbiotic nitrogen fixation. Consortial inoculations comprising of B. shewense (AU27) + A. soli (AU4) + Glomus sp.1 (AMF1) + Acaulospora sp.1 (AMF2) (T7) increased shoot length and shoot dry weight by 140% and 268%, respectively compared to un-inoculated control. Inoculations that involved B. shewense (AU27) + A. soli (AU4) increased shoot nitrogen by 260%, and 1200% increment of shoot P was recorded with inoculations of B. shewense (AU27) + Glomus sp.1 (AMF1) compared to un-inoculated control. These microbial inputs could be candidates for growth enhancement and shoot nitrogen and phosphorus improvement in Erythrina brucei and also as sustainable and eco-friendly agriculture input.