Bjerkandera adusta M1 inhibits the growth of Fusarium oxysporum f. sp. conglutinans and fusarium wilt incidence in Brassica napus L.

Bjerkandera adusta degrades polycyclic aromatic compound. However, its effect on preventing plant disease is unknown. We carried out both the confrontation culture and greenhouse pot experiments to address effects of B. adusta M1 strain on the growth of pathogenic Fusarium oxysporum f. sp. conglutinans (FOC) and incidence of Fusarium wilt in Brassica napus L. The results showed the hyphal growth rate of B. adusta M1 was significantly greater than that of FOC. The B. adusta M1 fermentation broth also significantly inhibited the growth of FOC hyphae by 62.79 ± 1.80%, which was greater than an inhibition rate of 40.63 ± 1.68% by the fungicide, carbendazim. The electron microscopic image showed the FOC hyphae was directly penetrated by the B. adusta M1 hyphae, indicating a strong mycoparasitism by B. adusta M1. Both the B. adusta M1 and its fermentation broth reduced the incidence and disease index of the Fusarium wilt in Br. napus, and the control effects of B. adusta M1 and its fermentation broth on Fusarium wilt were comparable or better than carbendazim. Furthermore, both the B. adusta M1 and its fermentation broth increased the activity of the defense enzymes including superoxide dismutase (25.92% and 22.38%), catalase (78.80% and 82.28%), peroxidase (46.64% and 6.83%) and phenylalanine ammonia-lyase (44.23% and 5.77%). Similarly, both the B. adusta M1 and its fermentation broth decreased the cell membrane permeability (48.68% and 33.71%) and malondialdehyde concentration (71.04% and 17.51%) of plant leaf. Therefore, B. adusta M1 can be applied as a potential biocontrol fungus to against Fusarium wilt.