Abstract:

【Objective】 The aim of the study is to induce the resistant isolate of Fusarium oxysporum f. sp. fragariae by in vitro cultivation on media containing tebuconazole and compare the biological characteristics between the sensitive and resistant isolates. 【Method】 The resistant isolate was selected on the media containing tebuconazole. By measuring the colony diameters, the characteristics of the resistant and sensitive isolates and the cross resistance of the resistant isolate to some fungicides were studied. 【Result】 The results showed that the resistance of the induced Fusarium oxysporum f. sp. fragariae isolate to tebuconazole reached 34.22 folds after 36-times selection compared with the sensitive isolate. The resistant level of tebuconazole-resistant isolate was stable. Meanwhile, the positive cross resistance to triadimefon and 6 other fungicides was reported. The optimal temperature was 25 ℃, and the optimum pH value was 9 for both sensitive and resistant isolates. The effects of different carbon and nitrogen sources on the growth and the spore production were different. 【Conclusion】 Fusarium oxysporum f. sp. fragariae is susceptible to produce resistant population in environment, and the resistance risk of Fusarium oxysporum f. sp. fragariae needs to be noticed in production.

Key words: Fusarium oxysporum f. sp. fragariae, tebuconazole resistance, biological characteristics