Sensitivity of Pathogen of Dioscorea op posita Stem Rot Disease to Tebuconazole in Hainan
ZHAO Zhi-xiang
CHEN Yuan
CHEN Mian-cai
XIAO Min
XIAO Tong-bin
Abstract：In order to provide practical and theoretical basis for the prevention and control of Dioscorea op posita stem rot disease ,the bioassay method of baseline sensitivity was developed on the basis of the effect of tebuconazole on the mycelium grow th and spore germination of Fusarium oxysporum f .sp .dioscorea .Thirty-two strains were obtained by single spore isolation .Virulence of tebuconazole on all of the strains was tested by the methods of mycelium grow th and spore germination .Then virulence regression equation was constructed and the sensitive distribution was analysed .The results showed that mycelium growth of the pathogen was affected by tebuconazole ,with the maximal EC50 of 0.407 005 μg/mL ,minimum EC50 of 0.063 797 μg/mL , and mean EC50 of (0.228 3 ± 0.008 5)μg/mL ,respectively .And spore germination was inhibited by tebuconazole to a greater extent ,with the mean EC50 as (0.031 8 ± 0.024 2)μg/mL ,ranging from 0.002 550 μg/mL to 0.104 858 μg/mL .Normal distribution analysis showed that the sensitivity of mycelium growth to tebuconazole fitted well with a normal distribution function ,but that of spore germination did not ,for which the span between the maximal EC50 and the minimum EC50 was big .In high concentration area ,there were still insensitive strains .This may be related to the change of environment ,and thus a few strains possessed a certain resistance .
Keywords：tebuconazoleDioscoreaopposita stem rot diseaseFusarium oxysporummycelium grow thspore germinationsensitivity
Publication Date：2014-01-01
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：5( 89-93 )