Mycorrhiza Helper Bacteria (MHB) forms symbiotic associations with ectomycorrhiza and Arbuscular Mycorrhiza (AM). Arbuscular Mycorrhizal Fungi (AMF) colonize the roots of approximately 80% of terrestrial plants. The most common beneficial effect of mycorrhizae is increased uptake of immobile nutrients, especially P, from soil. In the present study, it is mainly focussed on selection of an efficient MHB to enhance AM fungal activity and in turn increase the crop growth. In this study 40 MHBs were isolated from the rhizosphere soils of different crops from different agroclimatic zones of Andhra Pradesh. Among the 40 MHB isolates, most of them were gram positive (+ve), rod shaped and few were motile and endodpore formers. 23 isolates were positive for catalase, 18 isolates were positive for starch hydrolysis, 37 isolates were positive for MR test, 20 isolates were positive for VP test, 18 isolates were positive for casein hydrolysis, 12 isolates were positive for indole production and only one isolate was positive for H2S production. Fifty five per cent of the isolates were found positive for IAA production, maximum phosphrous solubilization was shown by the NDLCP2 with a Solubilization Index of 4.00 and highest potassium Solubilization Index was shown by the strain NDLCP3 (2.7) and among 40 bacterial isolates 38 bacterial isolates were positive for ammonia production. The MHB isolates which exhibited PGPR traits can be better utilized in agriculture as PGPR to enhance crop productivity.

MHB: Mycorrhiza Helper Bacteria, PGPR: Plant growth promotion, IAA, Ammonia production, Solubilization Index

The results of the present investigation revealed various morphological, biochemical and PGPR characters of MHB isolates. Based on these characters it can be concluded that certain MHB isolates which possess positive characters can be better utilized for enhancing the AM fungal activity and plant growth promotion. And further the two MHB isolates NDLCP2 and NDLCP3 were very efficient and which can be utilized for enhancing the AM fungal activity and crop growth by conducting further pot and field experiments.

G. Naganjali, R. Lakshmipathy, A. Vijaya Gopal, and P. Madhuvani (2022). Isolation and Identification of Mycorrhiza Helper Bacteria with Biochemical Characterization and Plant Growth Promoting Traits. Biological Forum – An International Journal, 14(3): 1609-1616.