Metabolic and biofungicidal properties of maize rhizobacteria for growth promotion and plant disease resistance

Abstract

Plant growth promoting rhizobacteria (PGPR) are known to influence plant growing both by direct and/or indirect mechanisms. This study aimed to establish PGPR profile of 15 bacteria isolated from maize (Zea mays L.) rhizosphere in Benin. These rhizobacteria were screened in vitro for the plant growth promoting traits like production of indole acetic acid (IAA), ammonia (NH 3), hydrogen cyanide (HCN), catalase, exopolysaccharides and antifungal activity against phytopathogenic fungi for example Fusarium verticillioides, that is an important maize pathogenic. Most rhizobacteria strains were found to produce catalase (100%), exopolysaccharides (100%), ammonia (86.66%), hydrogen cyanide (80%) and indole acetic acid (60%). Pseudomonas putida, Pseudomonas fluorescens and Azospirillum lipoferum have highly produced many of the investigated metabolites. Streptomyces hygroscopicus, Streptomyces fasciculatus, Pseudomonas aeruginosa, P. putida, P. fluorescens and A. lipoferum inhibited mycelial growth of F. verticillioides and Aspergillus ochraceus. P. fluorescens and P. aeruginosa were highly antagonistic against F. verticillioides (52.24% of mycelial growth inhibition) and A. ochraceus (58.33% of mycelial growth inhibition). These results suggest the possibility to use these rhizobacteria as biological fertilization to increase maize yield and the biological control of F. verticillioides and A. ochraceus.

Inoculation of Pseudomonas putida in Farmer Environment to Improve Growth and Yield: Maize (Zea mays L.) Trial in Sothern, Central and Northern (Benin)

“…In the North, the yield (48.34%) of plants treated with P. putida + ½ dose of NPK and Urea was lower compared to that obtained in the Center. The work carried out by these authors, [48,39], reported that the PGPR rhizobacteria including P. putida used in this study strongly produce indole acetic acid (AIA), ammonia (NH3), hydrocyanic acid (HCN) and exopolysaccharides. The significant improvement in grain yield obtained would be related to the multifunctional properties of P. putida.…”

“…These results are in line with those of [20] who obtained a 27.29% increase with P. putida + chitosan + ½ dose of NPK and Urea compared to the control. The rhizobacteria P. putida under study is capable of solubilizing phosphate [39] and promoting a better absorption of nutrients by plants from the soil [18]; which would justify the results obtained with inoculated plants. Moreover, it has been reported that the larger the leaf area, the more plants achieve good photosynthesis, which is favourable to better productivity [40].…”

Response of maize (Zea mays L.) crop to biofertilization with plant growth promoting rhizobacteria and chitosan under field conditions

“…Several authors argue that PGPR can promote the plant growth through various mechanisms such as the nitrogen fixation (N2) and trace elements solubilization such as phosphate (P), inhibition of ethylene synthesis by the plant, the synthesis of plant hormones or vitamins and by decreasing the toxicity of heavy metals (Whipps, 2001;Dobbelaere et al, 2003;Cakmakci et al, 2006;Orhan et al, 2006). Noumavo et al (2015) reported that the rhizobacteria strongly produced Indole Acetic Acid (IAA), ammonia (NH3), hydrogen cyanide (HCN), exopolysaccharides and exhibit strong antifungal activity against Fusarium verticillioides, real pathogen of maize.…”

Synergistic Effects of Plant Growth Promoting Rhizobacteria and Chitosan onIn VitroSeeds Germination, Greenhouse Growth, and Nutrient Uptake of Maize (Zea maysL.)

“…Noumavo et al [8] observed a clear improvement of in vitro maize seeds germination and greenhouse growth after seeds inoculation by PGPR and their various combinations. These rhizobacteria have strongly produced Indole Acetic Acid (IAA), ammonia (NH 3 ), hydrogen cyanide (HCN), and exopolysaccharides and exhibit strong antifungal activity against Fusarium verticillioides , real pathogen of maize [9]. …”

“…Indeed, chitosan is a natural polymer derived from chitin, commonly founded in the carapace of crustaceans, insect cuticle, and fungi walls [11]. This biopesticide is also a stimulator of flowering and fruition [12] and also used as a plant growth regulator [9]. …”