Fertilizer-dependent efficiency of Pseudomonads for improving growth, yield, and nutrient use efficiency of wheat (Triticum aestivum L.)

Abstract

Acquisition of nutrients by plants is primarily dependent on root growth and bioavailability of nutrients in the rooting medium. Most of the beneficial bacteria enhance root growth, but their effectiveness could be influenced by the nutrient status around the roots. In this study, two 1-aminocyclopropane-1-carboxylate (ACC)-deaminase containing plant-growth-promoting rhizobacteria (PGPR), Pseudomonas fluorescens and P. fluorescens biotype F were tested for their effect on growth, yield, and nutrient use efficiency of wheat under simultaneously varying levels of all the three major nutrients N, P, and K (at 0%, 25%, 50%, 75%, and 100% of recommended doses). Results of pot and field trials revealed that the efficacy of these strains for improving growth and yield of wheat reduced with the increasing rates of NPK added to the soil. In most of the cases, significant negative linear correlations were recorded between percentage increases in growth and yield parameters of wheat caused by inoculation and increasing levels of applied NPK fertilizers. It is highly likely that under low fertilizer application, the ACC-deaminase activity of PGPR might have caused reduction in the synthesis of stress (nutrient)-induced inhibitory levels of ethylene in the roots through ACC hydrolysis into NH(3) and alpha-ketobutyrate. The results of this study imply that these Pseudomonads could be employed in combination with appropriate doses of fertilizers for better plant growth and savings of fertilizers.

Effects of phosphorus fertilization and Pseudomonas fluorescens strain on the growth and yield of faba bean (Vicia faba L.)

“…Phosphorus also improves nitrogen metabolism in plants (Li and Zhao, 1990). Several groups of soil bacteria such as Pseudomonas exhibit phosphatesolubilizing ability through production of organic acids (Shaharoona et al, 2008). By changing the environmental acidity and enzymatic processes, they release the insoluble P of soil in the form of organic phosphoric acid, which increases its mobility in the soil (Chung et al, 2005;Gulati et al, 2010).…”

“…The use of growth-promoting bacteria can increase the growth and yield of crops through direct and indirect mechanisms. It has been proven that these bacteria increase the qualitative/quantitative yields of most crops through biological fixation of nitrogen, biological control of plant pathogens (Saravanakumar et al, 2007;Dey et al, 2004), vitamin production, increased iron absorption by siderophore secretion (Shaharoona et al, 2008;Braud et al, 2009) and production of the plant hormones cytokinin, auxin and gibberellin (Dey et al, 2004), decreasing levels of ethylene by production of Acc deaminase (Shaharoona et al, 2008) and increasing phosphorus solubility. Previous studies have shown that co-inoculation of phosphate-solubilizing bacteria (PSB) with other growth-promoting rhizobacteria decreased phosphate fertilizer consumption by 50% without a significant reduction in grain yield (Jilani et al, 2007;Yazdani et al, 2009).…”

Tratamento de sementes com rizobactérias na produção de cebola

“…Sabe-se, no entanto, que os isolados pertencem aos gêneros Bacillus e Pseudomonas, que são residentes comuns do filoplano de plantas cultivadas, além de serem isolados da rizosfera de várias espécies vegetais (KLOEPPER et al, 2004;SHAHAROONA et al, 2008). Além disso, LODEWYCKX et al (2002) incluem esses gêneros entre os endofíticos comuns em várias espécies vegetais.…”

“…Vários gêneros bacterianos são conhecidos pela capacidade de promover o crescimento vegetal, dentre eles, Bacillus e Pseudomonas são de importância reconhecida e comercialmente utilizados como inoculantes e biofertilizantes em muitos países (KLOEPPER et al, 2004;BASHAN & BASHAN, 2005). Uma vez que a sustentabilidade é uma direção a ser seguida na produção de alimentos, o uso de rizobactérias é considerado uma alternativa para a redução ou substituição do uso de produtos químicos sintéticos (CASTRO & MELO, 2007;SHAHAROONA et al, 2008), seja diretamente como promotoras de crescimento, seja como agentes de controle biológico de doenças (FREITAS & AGUILAR-VILDOSO, 2004).…”

Effect of IAA produced by Pseudomonas aeruginosa 6a (bc4) on seed germination and plant growth of Glycin max

“…The increase in yield of crop might be attributed to the greater microbial and enzymatic activities and rapid release of the nutrients in the soil (Gryndler et al, 2008). PGPR improve plant growth by enhancing the availability of nutrients (N, P and K) (Shaharoona et al, 2008).…”