Determination of antagonistic potential of endophytic bacteria isolated from lettuce against lettuce white mould disease caused by Sclerotinia sclerotiorum

Abstract

In this study, biocontrol efficiency of endophytic bacterial isolates obtained from the leaf lettuce (Lactuca sativa L.) healthy plants was investigated against white mould disease agent Sclerotinia sclerotiorum in vitro and in vivo conditions. Antagonistic efficiency of endophytic bacterial isolates was determined to inhibit mycelial growth and sclerotial germination, suppress disease incidence caused by S. sclerotiorum. A total of 48 endophytic bacterial isolates were isolated from different tissues of lettuce healthy plants. Mycelial growth and germination of sclerotia of S. sclerotiorum in vitro inhibited 18 bacterial isolates. Bacillus subtilis and B. amyloliquefaciens isolates were found to be the most efficient ones, which significantly inhibited the mycelial growth by 68.1-83.1%, germination of sclerotia by 82.7-89.6% and suppressed disease incidence by 55.7-75% caused by S. sclerotiorum. In addition, the fungal mycelium close to the inhibition zone in dual culture was denser and darker in colour. B. subtilis and B. amyloliquefaciens isolates caused significant morphological alterations in hyphae such as hyphal shrivelling and perforation close to the inhibition zone in dual culture. Significant suppression in the mycelial growth, sclerotial germination and disease incidence caused by endophytic bacterial isolates indicate that isolates of B. subtilis and B. amyloliquefaciens could be considered as possible biocontrol agents against soil-borne fungal diseases.

The Use of Rhizobacteria on White Rot Disease and Growth of Lettuce

“…The potential of bacterial strains, belonging to different genera, in the biological control of white rot disease in lettuce has been investigated in this study. Similarly, Soylu (2011) investigated the effect of antagonistic root bacterial strains (Lysobacter enzymogenes C3R5 and N4-7) and PGPR strains (Bacillus pumilus T4, B. amyloliquefaciens IN937a, Pseudomonas fluorescens WCS417r and P. putida 89B-61) on S. sclerotiorum. In in vitro studies, L. enzymogenes strain C3R5 and N4-7 significantly inhibited the pathogen whereas in in vivo, all strains showed a suppressive effect on disease development compared to the positive control.…”

“…The population of these bacteria, composed of different bacterial genera, increases rapidly and spreads in the rhizosphere. The rhizobacteria increase root growth and plant height and protect plants from diseases caused by soil-borne pathogens (El-Kafrawy, 2008;Soylu, 2011;Imriz et al, 2014;Abdeljalil et al, 2016;Sen et al, 2016). Many studies have been conducted on the biological control of S. sclerotiorum or S. minor, and the causative agent of white rot on lettuce (Budge and Whipps, 2001;Fiume and Fiume, 2005;Rabeendran et al, 2006;Chitrampalam et al, 2008;Villalta et al, 2012;Baniasadipour and Shahidi Bonjar, 2014;Elias et al, 2016;Yıldız and Cenberci-Coskun, 2017;Soylu et al, 2021;Ramona et al, 2022).…”

Identification of Alternaria, Aspergillus, Fusarium and Penicillium spp. on Onion Plant (Allium cepa L.) Growing in Hatay, Amasya and Tokat Provinces Using MALDI-TOF Mass Spectrometry

“…As a result of the analysis; the scores between 2.300-3.000 (green color) probable species identification, 2.000-2.299 (green color) reliable genus level diagnosis and probable species level diagnosis, 1.700-1.999 (yellow color) probable genus level diagnosis, 0.000-a score of 1.699 (red color) was considered as an unreliable diagnosis (Uysal et al, 2019;Soylu et al, 2021;Kara et al, 2022;Uysal et al, 2022).…”

“…Compared to traditional diagnostic methods that rely on biochemical testing and require long incubation procedures, MALDI-TOF MS has the advantage of identifying bacteria and fungi directly from colonies grown in culture media in a few minutes and with simple procedures (Kurt et al, 2020;Uysal et al, 2022). Many studies available in different systems have proven the reliability and accuracy of the method (Carolis et al, 2014, Uysal et al, 2019Soylu et al, 2021;. In this respect, it offers a powerful alternative to microscopic and molecular biology methods.…”

Çeşitli Kaynaklardan ve Ticari Gıda Takviyelerinden İzole Edilen Bacillus Türlerinin Bazı Probiyotik Özelliklerinin Karşılaştırmalı Değerlendirilmesi

“…Thanks to the antagonistic effects of Bacillus species, its use as a biological seed has also been proposed (Güldoğan et al, 2022) It has also been determined that due to the potent antagonistic activities of some Bacillus spp. isolates, citrus fruits have the potential to be used as biofungicides in the fight against post-harvest disease agents (Soylu et al, 2022) It has been stated that Bacillus probiotics are suitable for human consumption (Urdaci et al, 2004;Nithya and Halami, 2013). Most commercially available probiotic products consist of various microorganisms, especially Lactobacillus sp., Bifidobacterium sp., Streptococcus sp.…”