To identify Fusarium species associated with diseases of root and basal plate of onion, surveys were conducted in seven provinces of Turkey in 2007. Samplings were performed in 223 fields, and 332 isolates belonging to 7 Fusarium spp. were obtained. The isolates were identified as

Genetic variation among the isolates of Fusarium oxysporum f. sp. ciceris, the causal agent of chickpea wilt worldwide, was analysed using pathogenicity tests and molecular markers -random amplified polymorphic DNA (RAPD) and inter-simple sequence repeat (ISSR) polymorphism. Hundred and eight isolates were obtained from diseased chickpea plants in 13 different provinces of Turkey, out of which 74 isolates were assessed using 30 arbitrary decamer primers and 20 ISSR primers. Unweighted pair-grouped method by arithmetic average cluster analysis of RAPD, ISSR and RAPD + ISSR datasets provided a substantially similar discrimination among Turkish isolates and divided into three major groups. Group 1, 2 and 3 consisted of 41, 18 and 15 isolates, respectively. These methods revealed a considerable genetic variation among Turkish isolates, but no correlation with regard to the clustering of isolates from different geographic regions. Analysis of molecular variance confirmed that most genetic variability resulted from the differences among isolates within regions. Our results also indicated that the low-genetic differentiation (F ST ) and high gene flow (Nm) among populations had a significant effect on the emergence and evolutionary development of F. oxysporum f. sp. ciceris. This is the first report on genetic diversity and population structure of F. oxysporum isolates on chickpea in Turkey.

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Seventy-five isolates of Fusarium oxysporum f.sp. cepae, the causal agent of basal plate rot on onion, were obtained from seven provinces of Turkey. The isolates were characterized by vegetative compatibility grouping (VCGs) and restriction fragment length polymorphism (RFLP) analysis of the nuclear ribosomal DNA intergenic spacer region (IGS). Forty-eight vegetative compatibility groups were found, each containing a single isolate. Only one isolate formed strong heterokaryons with the reference isolates of VCG 0423. Five isolates were heterokaryon self-incompatible. Restriction fragment analysis with six different enzymes revealed 13 IGS types among 75 F. oxysporum isolates from Turkey as well as 16 reference isolates from Colorado, USA. The majority of single-member VCGs produced identical RFLP banding patterns with minor deviations, considerably different from those of the reference VCG isolates. These results suggested that isolates of F. oxysporum f.sp. cepae in Turkey derived from distinct clonal lineages and mutations at one or more vegetative compatibility loci restrict heterokaryon formation.

The effects of various fungicides on mycelial growth and spore germination of Ascochyta rabiei were determined by incorporating them into potato dextrose agar and measuring colony diameter and observing colony growth and spore germination at 20 ± 2°C. Eight fungicides prevented spore germination of the pathogen at concentrations of 0.125–2 μg/ml, three hindered mycelial growth at 2–4 μg/ml and seven failed to inhibit mycelial growth even at 128 μg/ml. The reference fungicide for the pathogen, chlorothalonil, stopped conidial germination at low rates but did not prevent mycelial growth at 128 μg/ml. Thirteen fungicides were tested against seed infections of the pathogen, and benomyl + thiram, carbendazim and carbendazim + chlorothalonil seed treatments gave more than 85% inhibition on both vacuum‐infiltrated and naturally infected seeds. Coating the seeds with polymers did not increase the effectiveness of fungicides. Three fungicides; (azoxystrobin, chlorothalonil and mancozeb), gave the highest protection in the field but protection decreased with increased inoculum pressure. Addition of humic acid to fungicide suspensions did not affect their performance.

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Genetic variation among the Azerbaijani isolates of anamorphs of Cochliobolus spp., the causal agents of common root rot of wheat, was evaluated using pathogenicity assessments, sequence analyses of the internal transcribed spacer (ITS) region and glyceraldehyde-3-phosphate dehydrogenase (GPDH) gene, as well as inter-simple sequence repeat (ISSR) and inter-primer binding site (iPBS) markers. Twenty-eight isolates used in this study were obtained from diseased wheat plants in cereal growing regions of Azerbaijan in 2017. Bipolaris sorokiniana, Curvularia spicifera, and Curvularia inaequalis were identified. Bipolaris sorokiniana isolates were the most virulent on wheat seedlings, followed by isolates of C. spicifera and C. inaequalis. Phylogenetic analyses of a combined dataset of the ITS and GPDH regions grouped the isolates into three clusters, each of which contained isolates of one species. The dendrogram derived from the unweighted pair-grouped method by arithmetic average (UPGMA) cluster analyses based on the data of ISSR and iPBS markers divided the isolates into three clusters in concordance to their taxonomic grouping at species level, but without correlation to their geographic origins. Population structure of isolates was estimated based on Bayesian modelling, and this showed three populations (K = 3) supporting the separation of isolates in the dendrogram with the greatest mean value of Ln likelihood (-893,8). Utilization of the markers either separately or together produced a high level of polymorphism at interspecies level, which allowed for the separation of species. Although both marker systems had similar discrimination power to reveal genetic differences among the species, ISSR markers were more informative for eliciting intraspecies polymorphisms within B. sorokiniana and C. spicifera isolates. This is the first study on genetic diversity and population structure of anamorphic stages of Cochliobolus associated with common root rot of wheat using iPBS markers.

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