Chapter 17 - Biodiversity and application of native arbuscular mycorrhizal fungal species with rhizobacteria on growth and yield enhancements in cowpea and aromatic black rice from North Eastern India

Abstract

Knowledge on the occurrence and distribution of native arbuscular mycorrhizal (AM) fungal species associated with crops in a particular area or land use types is important for utilizing them in any application. Therefore we assessed AM fungal community composition in soil and root colonization levels of AM and dark septate endophytic (DSE) fungi in cowpea and indigenous aromatic black rice plants, during seedling, flowering, and harvest stages in Manipur, North Eastern (NE) India. A total of 19 AM fungal spore morphospecies were identified from both field and trap pot culture soils and maximum species richness and spore density occurred during harvest stage. Roots of both crop species had AM and DSE colonization which varied significantly (P<.05) with crop growth stage, species, and sites. Further, we evaluated the influence of Acaulospora spinosa (AS), Funneliformis geosporus (FG), Funneliformis mosseae (FM), and Rhizophagus fasciculatus (RF), individually and/or in combination with Rhizobium leguminosarum (RL), Azospirillum brasilense (AB), and Pseudomonas fluorescens (PF) on the plant growth and yield improvement in greenhouse conditions using sterilized soil in both crop species. Inoculation of FG+RF+RL+PF in cowpea and FM+AB in rice significantly (P<.05) enhanced root length, plant biomass, grain yield, and mycorrhizal colonization compared to uninoculated controls. However, nodulation, shoot length, and tissue nutrient contents were higher in cowpea plants inoculated with RL, FG+RF+RL, and FG+RF+PF. Similarly, rice plants inoculated with FM+AB also had a significantly (P<.05) higher shoot and grain P contents than other treatments. Thus, our results suggest that the inoculation of native AM fungi along with efficient bioinoculants could improve the overall growth and yield performance of cowpea and rice plants and are potential bioinoculants for the studied crops in NE India.