Inoculation of wheat with Azospirillum brasilense and Pseudomonas fluorescens: Impact on the production and culturable rhizosphere microflora

Use of Soil Microorganisms to Improve Plant Growth and Ecosystem Sustainability

“…The management applied to the soil could finally define each situation. Using the same technique, as described below, it was possible to establish that inoculation with certain soil bacteria also alter temporarily microbial communities associated with wheat (Naiman et al, 2009) A significant number of soil microorganisms are involved in mineralization of organic phosphorus. This must be converted to inorganic phosphorus to be used by plants.…”

“…They are associated with plants of agricultural interest and in many cases direct beneficial effects on growth and both nitrogen and phosphorous nutrition are observed. Because of that, they constitute an ecological and economical alternative to increase food production (Bashan et al, 2004;Caballero Mellado, 2004;Díaz-Zorita & Canigia Fernandez, 2008;Ferraris & Courerot, 2004;Naiman et al, 2009;Reed & Glick, 2004). However, it should be noted that the impact of interactions between crops and soil microbes on the circulation of nutrients can be considerable.…”

“…Thus, both predecessor crop and phosphorus fertilizer addition exert significant effects on it. For these reasons, it is important to know the microbial dynamics of cereal crops included in the crop sequence (Chiocchio et al, 2000;Menéndez et al, 1999;Studdert et al, 1997) and the effects of the introduction of microorganisms in the soil-plant system to provide a better understanding of these interactions which are known to help to agroecosystem sustainability (Naiman et al, 2009). It was observed that inoculation of wheat with a phosphorus solubilizer bacterium such as, Pseudomonas fluorescens can modify the mycorrhiza percentage and certain fungi structures during the growth cycle (Table 3).…”

Effect of Azospirillum brasilense and Methylobacterium oryzae Inoculation on Growth of Red Pepper (Capsicum annuum L.)

“…Bashan et al (2004) suggested that the good positive plant growth-promoting effects obtained under pot experiments cannot always be dependably reproduced under field conditions. Recently, Naiman et al (2009) also reported that inoculation of wheat with A. brasilense and P. fluorescens could not significantly increase the aerial biomass production and grain yield in a field experiment. This inconsistency restricts further development of plant growth promoting rhizobacteria as a commercial inoculum on large scale crop cultivations (Bashan and Holguin, 1997;Maheshwari, 2011).…”

Phytoextraction of soil cadmium and zinc by microbes-inoculated Indian mustard (Brassica juncea)

“…Furthermore, P. fluorescens, a known plant growth-promoting bacterium, has also ensured bioavailability of phosphorus for plant uptake, fixing nitrogen for plant use, sequestering essential trace elements like iron by siderophores and producing plant hormones like auxins, cytokinins and gibberellins, beside cleaving the plant ethylene precursor ACC and thus lowering the ethylene level in growing and/or stressed plants due to presence of 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase (Glick et al 1999). Naiman et al (2009) have also reported that inoculants of Azospirillum brasilense Az1 and Az2 and P. fluorescens Pf increased average aerial biomass by 12%, root biomass by 40% and grain yield of wheat by 16%. Further, the occurrence of induction in the plant's resistance against fungal, bacterial and viral diseases (Maurhofer et al 1998) and enhancement of tolerance against biotic and abiotic stresses, including heavy metals (Whiting et al 2001) in response to PGPR (P. fluorescens) cannot be ignored in the present study.…”