ISSN 1392-3196 / e-ISSN 2335-8947
Zemdirbyste-Agriculture, vol. 107, No. 2 (2020), p. 105–112
DOI 10.13080/z-a.2020.107.014

Biological control potential of rhizosphere bacteria with ACC-deaminase activity against Fusarium culmorum in wheat

Gül IMRIZ, Fatih ÖZDEMIR, Mehmet Sait KARACA, Murat Nadi TAŞ, İlker TOPAL, Birol ERCAN


Fusarium culmorum (W.G. Smith) is one of the fungal soil-borne plant pathogens causing significant yield and quality losses in cereals. Chemical attempts are not only insufficient for controlling such pathogens, but also they bring hazardous effects on the environment and living organisms. Therefore, environment-friendly plant-beneficial microorganisms including bacteria would replace chemical control agents as promising and sustainable pest management. Numerous studies showed that some strains of plant growth-promoting rhizobacteria comprising the enzyme ACC (1-aminocyclopropane-1-carboxylate)-deaminase could promote the plant growth acting as a biological control agent by lowering the level of excessive ethylene in plants exposed to biotic and abiotic stresses. This study was aimed to evaluate the rhizobacterial isolates obtained from rhizosphere of cereal plants in Konya and Karaman provinces in Turkey for potency of enzyme ACC-deaminase activity and in vitro/in vivo suppression ability on F. culmorum. In total 31 out of 463 rhizobacterial isolates successfully suppressed in vitro growth of F. culmorum on potato dextrose agar following dual-culture technique. Afterwards, the successful isolates were examined for ACC-deaminase activity using ACC as the sole nitrogen (N) source. Two isolates coded as Gu2 and 127b with the highest enzyme ACC-deaminase activity were included in pot trials under controlled conditions for assessing in vivo pathogen suppression ability on wheat seedlings. The in vivo pathogen suppression efficiency of Gu2 and 127b isolates was determined as 81.25% and 37.50%, respectively. It was determined that both rhizobacterial isolates belonged to Bacillus spp. with high reliable score based on MALDI Biotyper System classification results.

Key words: combat, enzyme, pathogen, rhizobacteria, soil, wheat.

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