Research Article

Isolation, Identification, and In Vitro Biological Control of Olive Knot Disease Agent With Antagonist Bacillus spp.

Volume: 28 Number: 6 October 20, 2025
TR EN

Isolation, Identification, and In Vitro Biological Control of Olive Knot Disease Agent With Antagonist Bacillus spp.

Abstract

In this study, 18 olive orchards in the provinces of Mersin and Osmaniye in Türkiye, where olives are grown, were visited, and 26 bacterial isolates were obtained from six trees showing symptoms of olive knot disease. The bacterial isolates were identified by morphological and biochemical tests (Gram reaction and LOPAT characteristics) and by MALDI-TOF MS analysis at the species level. Based on pathogenicity tests, all bacterial isolates were identified as Pseudomonas savastanoi pv. savastanoi. In biocontrol studies, the antibacterial effects of 19 epiphytic biocontrol agent (BCAs) bacterial isolates were investigated using in vitro dual culture tests in Petri dishes. In the dual culture test, all antagonistic BCA bacterial isolates formed an inhibition zone of 2.0 to 9.3 mm and thus inhibited the growth of the pathogen. Diagnostic tests for BCA bacterial isolates performed with MALDI-TOF identified all effective antagonist isolates as Bacillus spp. Five antagonist bacterial isolates belonging to the same statistical group (Bacillus subtilis KSY9, Bacillus subtilis ABK-FY-2-5, Bacillus amyloliquefaciens ssp. plantarum MTHM.3, Bacillus amyloliquefaciens ssp. plantarum FT2.1 and Bacillus amyloliquefaciens ssp. plantarum MTHM2) were identified as the most successful in inhibiting pathogen growth. The isolate Bacillus subtilis KSY9 formed an average inhibition zone of 9.33 mm and was thus the most successful antagonist. This study once again emphasises the importance of biological control as an environmentally friendly method of organic farming to combat diseases.

Keywords

Supporting Institution

Osmaniye Korkut Ata University’s Scientific Research Projects Unit

Project Number

OKÜBAP-2023-PT2-005

References

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Details

Primary Language

English

Subjects

Phytopathology

Journal Section

Research Article

Authors

Ogün Küçüktamer
0009-0003-0525-6187
Türkiye

Early Pub Date

August 14, 2025

Publication Date

October 20, 2025

Submission Date

May 7, 2025

Acceptance Date

July 3, 2025

Published in Issue

Year 2025 Volume: 28 Number: 6

APA
Küçüktamer, O., & Pınar Aktepe, B. (2025). Isolation, Identification, and In Vitro Biological Control of Olive Knot Disease Agent With Antagonist Bacillus spp. Kahramanmaraş Sütçü İmam Üniversitesi Tarım Ve Doğa Dergisi, 28(6), 1414-1426. https://doi.org/10.18016/ksutarimdoga.vi.1686824


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