Biological Control of Verticillium Wilt on Olive Trees by the Salt-Tolerant Strain Bacillus velezensis XT1

Microorganisms

Marta Torres¹  Inmaculada Sampedro¹  Victoria Béjar¹  Fernando Martínez-Checa¹  David Castro²  Borja Torres² 

[1] Department of Microbiology, Faculty of Pharmacy, University of Granada, 18071 Granada, Spain;Xtrem Biotech S.L., European Business Innovation Center, 18100 Granada, Spain;

关键词: biocontrol;    antifungal activity;    crop protection;    Bacillus velezensis;    Verticillium dahliae;    Olea europaea;   

DOI  :  10.3390/microorganisms8071080

来源: DOAJ

【 摘 要 】

Verticillium wilt, caused by the pathogen Verticillium dahliae, is extremely devastating to olive trees (Olea europea). Currently, no successful control measure is available against it. The objective of this work was to evaluate the antifungal activity of Bacillus velezensis XT1, a well-characterized salt-tolerant biocontrol strain, against the highly virulent defoliating V. dahliae V024. In vitro, strain XT1 showed to reduce fungal mycelium from 34 to 100%, depending on if the assay was conducted with the supernatant, volatile compounds, lipopeptides or whole bacterial culture. In preventive treatments, when applied directly on young olive trees, it reduced Verticillium incidence rate and percentage of severity by 54 and ~80%, respectively. It increased polyphenol oxidase (PPO) activity by 395%, indicating an enhancement of disease resistance in plant tissues, and it decreased by 20.2% the number of fungal microsclerotia in soil. In adult infected trees, palliative inoculation of strain XT1 in the soil resulted in a reduction in Verticillium symptom severity by ~63%. Strain XT1 is biosafe, stable in soil and able to colonize olive roots endophytically. All the traits described above make B. velezensis XT1 a promising alternative to be used in agriculture for the management of Verticillium wilt.

【 授权许可】

Unknown