Erper, İsmail Ondokuz Mayıs Üniversitesi - Ziraat Fakültesi - Bitki Koruma Bölümü, Turkey , Balkaya, Ahmet Ondokuz Mayıs Üniversitesi - Ziraat Fakültesi - Bahçe Bitkileri Bölümü, Turkey , Türkkan, Muharrem Ordu Üniversitesi - Ziraat Fakültesi - Bitki Koruma Bölümü, Turkey , Kılıç, Gülay Ondokuz Mayıs Üniversitesi - Ziraat Fakültesi - Bitki Koruma Bölümü, Turkey

Determination of fungal pathogens causing root and crown rot in winter squash(Cucurbita maxima Duch.) growing areas in The Black Sea Region and reactions ofsome winter squash genotypes against these pathogens

33909

Various soil-borne fungal pathogens are widespread in cucurbit-growing areas and cause wilting, root and crown rot diseases in the world. This study was conducted to determine fungal pathogens related to rootand crown rot disease in winter squash-growing areas and the responses to these pathogens of somewinter squash genotypes which were chosen based on individual selection method in terms of suitabilityfor sweet intended use, The survey studies were conducted in 65 fields in Samsun, Amasya, Sinop andOrdu provinces. A total of 140 fungal isolates were obtained from diseased plant samples. Elevendifferent species of Fusarium genus were obtained, and among them, F. oxysporum was the species with the highest isolation ratio (21.4%). The isolation ratio was 2114% for Rhizoctonia solani AG 4 whereas it was 2.1% for Pythium spp. Pre-pathogenicity tests were carried out on “Arıcan 97” winter squash varietywith 78 isolates selected from Fusarium spp., R. solani and Pythium sp. isolates. At the experiment, 3 isolates (F. solani f.sp. cucurbitae (F-42), Pythium sp. (Pyt-3), R. solani AG 4 (Rhi-3) which exhibited high virulence phenotypes in the study and F. solani f.sp. cucurbitae race 1 (used for positive control) were selected, and the resistance reactions of 5 squash genotypes (G14, 55ÇA06, 57Sİ21, 55ÇA15,55BA03) against these isolates were tested. The differences among the reactions of winter squashgenotypes against the isolates studied were found to be statistically significant (P 0.05) according to the durability test results. All of the genotypes used in this study were found be moderately resistant (MR) tothe isolate F-42 of F. solani f.sp. cucurbitae.

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Fusarium spp. , Pathogenicity , Pythium spp. , Resistance , Rhizoctonia solani , Winter squash

Anadolu Journal Of Agricultural Sciences

23