A 'six-step-strategy' to evaluate competence of plant growth promoting microbial consortia

Abstract

In this study a stepwise, statistically verifiable scientific protocol - 'six-step-strategy' - to develop a consortium is presented. Additionally, it introduces a novel in vivo plant bioassay - 'tube-in-tube' method - that gives faster (< three weeks) and reproducible results for selecting the most desirable consortia combinations. The study employs eight plant growth promoting microbes (PGPMs) with pre-established growth supporting abilities and no mutual antagonism. Following a two-factorial design, 15 consortia combinations (CCs) were developed from these PGPMs. Applying the principles of the 'six-step-strategy', combinations CC11, CC13 and CC4 showing significant increments (>100%) in root length and dry weight were recognized as the best performing consortia. The method thus shortlists the best and manageable number of consortia for further field trials.