Biopriming with a Native Microbial Consortium Favourably Modulates the Growth Dynamics and Yield of Amaranthus tricolor and Oryza sativa

Biopriming can be considered as a sustainable method that involves the application of beneficial plant growth-promoting microorganisms to seeds or seedlings, enhancing their growth, vigour, and ultimately the yield of the crop plants. The microbial symbionts of epiphytic orchids may function as efficient plant growth promoters as they are particularly beneficial in environments where contact with the soil is limited. The present study is an attempt to explore the biopriming effects of microbial consortium, prepared from the bacterial and fungal associates of the epiphytic endemic orchid Dendrobium ovatum, on the growth of Amaranthus tricolor (Red Amaranth) and Oryza sativa (Uma MO16). The bacterial and fungal isolates that displayed beneficial plant growth-promoting capabilities like extracellular enzyme production, Indole-3-Acetic Acid (IAA), hydrogen cyanide, phosphate solubilisation, and ammonia production were selected for the preparation of bacterial, fungal, and bacterial-fungal consortium. The various growth parameters like shoot and root length, plant biomass, Chlorophyll a fluorescence parameters, pigment composition, metabolite production (total soluble sugars, amino acids, and total phenolics), and yield parameters were analysed and compared in bioprimed and non-primed A. tricolor and O. sativa seedlings. The results demonstrate increased biomass, enhanced accumulation of photosynthetic pigments and photochemistry, metabolite production, and yield in all the bioprimed plantlets, compared to the control. The results demonstrate the enhanced seedling vigour and health, culminating in enhanced yield of crop plants. The findings from the present study point towards the growth- and yield-enhancing effect of biopriming using the microbial consortium prepared from the native aerial epiphytic microorganisms on the crop plants that can contribute towards sustainable agriculture practices and ecosystem preservation.