Effect of wheat cultivars with different resistance to Fusarium head blight on rhizosphere Fusarium graminearum abundance and microbial community composition

Abstract

Wheat (Triticum aestivum L.) cultivars vary in their resistance to Fusarium head blight (FHB), while it is poorly understood how different cultivars influence FHB-causing Fusarium graminearum abundance in rhizosphere soil. A field experiment was conducted to investigate the influence of three wheat cultivars on FHB index, rhizosphere soil F. graminearum abundance, chemical properties, and microbial community composition and metabolic profiles. The cultivars were Sumai3 (SM), Yangmai13 (YM), and Annong8455 (AN), representing high, intermediate, and low resistance to FHB, respectively. Both wheat FHB index and rhizosphere F. graminearum abundance were ranked as SM < YM < AN (p < 0.05). Wheat cultivar influenced community composition with a higher fungal Shannon index in the SM and YM rhizosphere than in the AN rhizosphere. The relative abundances of Arthrobacter, Pseudomonas, Acremonium and Guehomyces that contain microbes with potential to have beneficial effects on pathogen suppression were higher in the rhizosphere soil of SM, relative to AN. Microorganisms in the SM rhizosphere used less carboxylic acids and phenolic acids but more amino acids than those in the AN rhizosphere. Rhizosphere F. graminearum abundance was positively correlated to utilization of carboxylic acids, but negatively correlated with NH4+-N content, fungal Shannon index, and relative abundance of Arthrobacter, Pseudomonas, Acremonium and Guehomyces. The different F. graminearum abundance in rhizosphere soil of wheat cultivars with different resistance to FHB may be associated with the changes in rhizosphere soil chemical properties and microbial community composition and function.