Fusarium graminearum and F. culmorum are the major causal agents of Fusarium head blight in Turkey. They produce trichothecenes such as deoxynivalenol (DON), nivalenol (NIV) and their several acetylated derivatives, 3-acetyldeoxynivalenol (3-ADON) and 15-acetyldeoxynivalenol (15-ADON). In this study, a total of thirty-three isolates of F. graminearum and F. culmorum were collected from various regions and three different hosts. They were identified by amplification of tri5 gene cluster. Totally 32 isolates, 21 of F. culmorum and 11 of F. graminearum, were determined as DON chemotype, while only one F. graminearum isolate (1F) was detected as a NIV. A 282 base pair (bp) band for tri13 gene and also ranging from 458 to 535 bp bands for tri7 gene were amplified in all DON producers' genomes. Further analysis of DON chemotype based on tri3 gene amplification showed that all isolates of F. graminearum displayed 15-ADON sub-chemotype. They yielded a 863 bp amplicon. Similarly, 3-ADON sub-chemotype was identified in F. culmorum' isolates except F13. As a result of tri3 gene assay, it was produced a 583 bp fragment in these twenty isolates. It is the first report that a F. graminearum isolate depicts NIV chemotype in agricultural regions of Turkey. According to our findings, DON chemotype is predominating in our country. Also, it is presented that most of the F. graminearum isolates have 15-ADON sub-chemotype, while all F. culmorum's belong to 3-ADON which possess full length amplicon of tri7 gene.

Fusarium graminearum and F. culmorum are phytopathogens, which cause destructive diseases in cereals. Epidemics of these phytopathogens are caused by mycotoxin contamination and the reduction of crop quality. In this study, the alteration due to in vitro camphor treatment on F. culmorum 9F and F. graminearum H11 isolates was investigated in terms of epigenetic, cellular, and transcription levels. Camphor with different concentrations (0.2, 0.4, 0.8, 1, 2, and 4 µg/µL) was applied to potato dextrose agar (PDA) growth media. The minimum inhibitory concentration (MIC) and the half maximal inhibitory concentration (IC50) were calculated as 2 and 1 µg/µL, respectively. hog1, mst20, CAT, POD, mgv1, stuA, and tri5 genes, which are related to various cellular processes and pathogenesis, were examined by qPCR assay. qPCR analysis showed that camphor treatment leads to the downregulation of tri5 expression but the upregulation of the remaining genes. Apoptosis and oxidative stress were confirmed via acridine orange/ethidium bromide (AO/EB) and dichlorofluorescin diacetate (DCF-DA) staining, respectively. Moreover, coupled restriction enzyme digestion-random amplification (CRED-RA) assay, used for DNA methylation analysis, was carried out to evaluate epigenetic alterations. The decrease in genomic template stability (GTS) values, which resulted due to the alterations in random amplified polymorphic DNA (RAPD) profiles caused by camphor treatment, were detected as 97.60% in F. culmorum 9F and 66.27% in F. graminearum H-11. The outer and inner methylated cytosine profiles are determined by CRED-RA assay as type I–IV epigenetic alterations. The outcomes indicated that camphor could lead to alterations at several molecular levels of F. graminearum and F. culmorum.

To characterize the isolates of F. graminearum and F. culmorum fungi from Turkey and Iran, we performed ISSR analysis with 18 non-anchored and 23 anchored (including ten novel) primers. Amplification product sizes were 0.2-3.5 kb. In total, 405 bands were scored, 24 of which (5.92%) were polymorphic. The similarities among F. graminearum isolates were calculated as 62.3-99%, and among F. culmorum as 65.7-94.3%. Moderate genetic variation at intra- and inter-specific levels was determined, and the average intraspecific genetic diversity values were 80.65% for F. graminearum, and 80% for F. culmorum. Cluster analysis separated the isolates into two main clades. Group I consisted of F. culmorum isolates from Turkey that produced DON mycotoxin. Group II contained all F. graminearum isolates that were deoxynivalenol (DON) and nivalenol (NIV) chemotypes from Turkey and Iran. Both groups I and II were divided into two subgroups including their divisions. Phenons in group II included isolates distributed in the same geographic region. ISSR markers clustered isolates within a definite order according to their species. Isolates from the same agro-ecological locations were also kept together in subdivisions. The novel ISSR markers developed for the first time in this study contribute to differentiating between Fusarium isolates according to their species and geographic regions.

Fusarium culmorum is a pathogen of economically important grain crops. In this work, Rep-PCR was used to identify genetic diversity in F. culmorum isolates which have been collected from wheat fields in Turkey. Reproducible genomic fingerprints were amplified in each strain by PCRs of prokaryotic repetitive extragenic palindromic (REP), enterobacterial repetitive intergenic consensus (ERIC) and BOX sequences. Totally 104 molecular markers were evaluated and similarity comparisons were shown as a dendrogram. The average genetic diversity was 52.3% ranging from 15.8% to 88.7% according to the Rep-PCR data. Cluster analysis showed agreement with the distance of sampling locations. The highest genetic similarity (84.2%) was determined between two F. culmorum isolates (F1 and F2) originated from the same agro-ecological region. Our results showed that Rep-PCR is convenient and rapid for genetic diversity analyses and strain differentiation in F. culmorum.

In this manuscript, thirty yellow-pigmented Gram-positive bacteria were isolated from natural intestine microflora and from sea water around the marine cage of a rearing tank of common dentex (Dentex dentex), in the Aegean Sea on the Turkish coast and were characterized. Eighteen isolates were assigned to the species Micrococcus luteus, the other twelve to the species Bacillus marisflavi. Eight representative strains, six from B. marisflavi and two from M. luteus, were chosen for further 16S rDNA analyses. A pathogenicity assay for the isolated bacterial strains was carried out in rainbow trout and it evidenced absence of pathogenicity in the tested strains. The isolated strains were tested for in vitro antagonistic activity against Listonella anguillarum, a pathogen bacterium diffused in Mediterranean aquaculture and affecting various fish species. The isolated bacterial strains showed antagonistic activity against the pathogenic bacterium, suggesting a possible role of isolates as probiotics. In this study, for the first time, bacterial strains of the species B. marisflavi, known as an environmental species, were recovered in the gut microbiota of a healthy fish. The use of the isolates characterized in this study, mainly the yellow-pigmented bacterium, is suggested as possible probiotics to improve fish health, along with alternative methods of maintaining a healthy environment.