S.N. Elansky1,2, M.A. Pobedinskaya1, I.A. Kutuzova1, M.M. Yarmeeva1, T.A. Gurkina2, L.Y. Kokaeva1,3
1Lomonosov Moscow State University, Leninskie gory, 1, str. 12, Moskva, 119991, Russian Federation
2Peoples’ Friendship University of Russia, ul. Miklukho-Maklaya, 6, Moskva, 117198, Russian Federation
3A.G. Lorkh All-Russian Research Institute of Potato Farming, ul. Lorkha, 23, pos. Kraskovo, Lyuberetskii r-n, Moskovskaya obl., 140051, Russian Federation
Abstract. We evaluated the growth inhibition of colonies of phytopathogenic fungi Helminthosporium solani, Colletotrichum coccodes, and Rhizoctonia solani with fungicides difenoconazole (Skor), azoxystrobin (Kvadris), fludioxonil (Maksim), pencycuron (Prestizh), thiabendazole (Tekto), and colloidal silver (Zeroxxe). We used the isolates of C. coccodes, H. solani, R. solani from potato tubers, grown in 2013–2016 in the Russian Federation, as well as from seed potato from the Federal Republic of Germany (FRG) and the Netherlands. The type of isolates was determined by the culture-morphological features, the structure of the nuclear ribosomal gene section and internal transcribed spacers (ITS1-5.8S-ITS2). The isolates were cultured with wort agar and fungicides at concentrations of 0.1; 1; 10; 100 mg/L of an active substance, in the control – without fungicides. In the case of thiabendazole and pencycuron, a concentration of 1000 mg/L was also used. There were no strains with high resistance to difenoconazole (EC50 for H. solani was 0.05–0.13 mg/L, for R. solani – 4–70 mg/L, for C. coccodes – 0.05–0.12 mg/L) and colloidal silver (EC50 was 7.0–72.7, 0.75–7.8, 1.2–7.0 mg/L, respectively). Thiabendazole was highly effective (EC50 was 0.9–more than 100; 4.9–8.5; 0.9–50.3 mg/L, respectively), but it was revealed four highly resistant strains (EC50 was more than 1000 mg/L) of H. solani, which is due to the same mutations that of the European and American strains. Fludioxonil inhibited the growth of C. coccodes (EC50 was 0.60–0.90 mg/L) and R. solani (EC50 was 0.05–0.09 mg/L), but, when cultured for more than 20 days, strains formed stable sectors that grew faster than the original isolate. Pencycuron showed a good fungicidal effect only in relation to R. solani (EC50 was 0.05–more than 100 mg/L), however, three highly resistant strains of this fungus (EC50 was more than 1000 mg/L) were found. Resistance to azoxystrobin was very different, which is related to the work of alternative respiratory tracts when growing on a nutrient medium. In the field, its effectiveness may be higher.
Keywords: potato; potato protection; Helminthosporium solani; Colletotrichum coccodes; Rhizoctonia solani; fungicides; difenoconazole; azoxystrobin; fludioxonil; pencycuron; thiabendazole; colloid silver; Zeroxxe.
Author Details: S.N. Elansky, D. Sc. (Biol.), leading research fellow (e-mail: Этот адрес электронной почты защищён от спам-ботов. У вас должен быть включен JavaScript для просмотра.); M.A. Pobedinskaya, leading engineer; I.A. Kutuzova, lab technician; M.M. Yarmeeva, student; T.A. Gurkina, student; L.Y. Kokaeva, Cand. Sc. (Biol.), research fellow.
For citation: Elansky S.N., Pobedinskaya M.A., Kutuzova I.A., Yarmeeva M.M., Gurkina T.A., Kokaeva L.Y. Resistance of Helminthosporium solani, Colletotrichum coccodes, and Rhizoctonia solani to the Fungicides, Applied for Tuber Treatment. Dostizheniya nauki i tekhniki APK. 2018. Vol. 32. No. 3. Pp. 50-53 (in Russ.). DOI: 10.24411/0235-2451-2018-10310.