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Ascochyta blight caused by Ascochyta rabiei is a globally important chickpea disease. Host resistance to Ascochyta blight is considered the most practical and effective means of control, but breeding has been hindered by a lack of effective resistance sources, and time‐consuming, labour‐intensive traditional methods to screen the resistance level of chickpea genotypes. This paper evaluated the progression of pathogen infection and the disease reaction of chickpea genotypes to Ascochyta blight by traditional and molecular methods. The resistance level of 84 chickpea genotypes was assessed by a quantitative polymerase chain reaction assay (qPCR) using a standard curve produced by various known amounts of pathogen DNA and compared with disease scores based on visual assessments 8 days after inoculation. Disease assessments revealed statistically significant differences between the resistance levels of chickpea genotypes, while the quantity of target DNA in the samples inoculated with the pathogen ranged from 0.004 to 83.37 ng. Our results showed a close relationship between the visual assessment of disease severity and the quantification of the target DNA in chickpea genotypes. The genotypes Tüb‐35, Tüb‐47, Tüb‐26, Tüb‐82, Tüb‐65 and Tüb‐69 were classified as highly resistant to Ascochyta blight based on the results of both assays used for screening chickpea genotypes. This qPCR analysis could be used to quantify disease progression in plant tissues and screen chickpea genotypes as a potential alternative to visual assessment of resistance levels in breeding programmes. [ABSTRACT FROM AUTHOR]

Apple scab caused by Venturia inaequalis is one of the most economically important diseases of apple worldwide. Disease management is largely based on the frequent applications of fungicides, but fungicide resistance is a common problem. In this study, we monitored the development of resistance to four MBC, DMI and QoI group fungicides with different modes of action in V. inaequalis from apple orchards in Turkey. Sensitivity of V. inaequalis from 27 orchards in six provinces was evaluated to thiophanate‐methyl, myclobutanil, difenoconazole and kresoxim‐methyl by mycelium growth assay and molecular tools. Baseline sensitivity was determined in wild isolates of V. inaequalis from apple trees that had never been treated with any fungicides. EC50 value for thiophanate‐methyl, myclobutanil, difenoconazole and kresoxim‐methyl was 0.0992, 0.0315, 0.0048 and 0.0192 μg/ml, respectively. Of the 470 single spore isolates evaluated, 93.4% was very highly resistant to thiophanate‐methyl, while 27.5% and 50.2% were resistant and moderately resistant to myclobutanil, respectively. Difenoconazole and kresoxim‐methyl resistance were confirmed in 7.45 and 97% of the isolates tested, respectively. Molecular studies revealed that resistance to MBC fungicide, thiophanate‐methyl resulted from a mutation at codon 198 in β‐tubulin gene, while the G143A mutation of cytochrome b caused resistant to the QoI, kresoxim‐methyl. This study represents the first report of V. inaequalis resistance to several fungicides from apple orchards in Turkey. The resistance risk to these fungicides should be taken into consideration in the management of apple scab in Turkey. [ABSTRACT FROM AUTHOR]

ABSTRACT Triaxial residual tensile stresses resulting after cooling a 3D woven composite from the curing temperature cause cracking in the resin pockets for weave architectures that have high through-the-thickness constraint. We show how curing cycle modifications can reduce the hydrostatic tensile stress generated by thermal mismatch during cooling of Hexcel RTM6 epoxy resin constrained in a quartz tube which simulates extreme constraint in a composite. The modified curing schedule consists of a high temperature cure to just before the glass transition, a lower temperature hold that takes the resin through the glass transition thereby freezing in the zero stress state, followed by high temperature cure to bring the resin to full conversion. We show that this process is sensitive to heating rates and can reduce the zero stress state of non-toughened RTM6 resin to a temperature similar to a commercial rubber-toughened resin, Cycom PR520. © 2016 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2016, 133, 43373. [ABSTRACT FROM AUTHOR]

Isolates of Rhizoctonia spp. associated with stem canker and black scurf disease of potato were examined for their anastomosis group, sequence variations in the ITS-5.8S rDNA region, pathogenicity and sensitivity to fungicides. A total of 92 isolates were obtained from diseased tuber, stolon and sprouts of the potato plants, collected from five districts of Bolu province, Turkey. Based on the anastomosis group and the similarity of the nucleotide sequence of the ITS-5.8S rDNA, most of the isolates (81.5%) were identified as AG 3 PT. Other isolates belonged to AG 2-1 (1.08%), AG 2-2 IV (1.08%), AG 4 HG II (8.07%), AG 5 (2.17%), binucleate Rhizoctonia AG A (1.08%) and AG K (4.35%). Pathogenicity tests showed that isolates of AG 3 PT, AG 4 HG II and AG 5 caused similar degrees of disease severity on 45-day-old potato seedlings, whereas AG 2-1 was moderately virulent. AG 2-2 IV and binucleate Rhizoctonia spp. were weakly pathogenic or non-pathogenic on potato seedlings. In this study, anastomosis groups of Rhizoctonia spp. isolates associated with potato in Turkey were characterized for the first time using molecular techniques and classified at the level of subgroups. Furthermore, the effect of selected fungicides was evaluated on disease development caused by soil-borne inoculums of different anastomosis groups (AGs). Flutolanil and Bacillus subtilis QST 713 were found to be most effective against the Rhizoctonia isolates tested. These results revealed significant differences among the fungicides on disease development resulted from the different AGs. [ABSTRACT FROM AUTHOR]

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 F. oxysporum, F. solani, F. acuminatum, F. equiseti, F. proliferatum, F. redolens, and F. culmorum based on morphological and cultural characteristics. Also, species-specific primers were used to confirm the identity of Fusarium species. F. oxysporum was the most commonly isolated species, comprising 66.57% of the total Fusarium species. F. redolens was identified for the first time in onion-growing areas of Turkey. Selected isolates of each species were evaluated for their aggressiveness on onion plant. F. oxysporum, F. solani, F. acuminatum, F. proliferatum, and F. redolens were highly pathogenic, causing severe damping-off on onion plants cv. Texas Early Grano. Inter-simple sequence repeats (ISSR) markers revealed a high degree of intra- and interspecific polymorphisms among Fusarium spp. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Botrytis disease of tea was reported for the first time from Rize, Turkey. The causal agent was identified as Botrytis cinerea based on morphological and cultural characteristics. Also, the species-specific PCR assays confirmed the identification of all B.  cinerea isolates. The pathogen caused blight of shoots, buds, flowers and young leaves, shoot canker and leaf spots. The disease was observed in Rize central district and Derepazarı, Çamlıhemşin, Çayeli, Pazar, Hemşin, İkizdere, Ardeşen and İyidere districts. [ABSTRACT FROM AUTHOR]