Monitoring for the Resistance to Prochloraz of Fusarium Species Causing Bakanae Disease in Korea

Hyo-Won* Choi1   Yong Hwan Lee2   Sung Kee Hong3   Young Kee Lee1   Young Ju Nam1   Jae Guem Lee1   Song Hee Han1   

Abstract

ABSTRACT : To investigate the changes of the resistance to prochloraz of Fusarium species causing bakanae disease, Fusarium isolates were collected from various regions in Korea, and pathogenicity tests were performed using rice seeds. Minimum inhibitory concentration (MIC) and effective concentration of 50% (EC50) values of isolates were determined using the agar dilution method. High frequency distribution of MIC values of prochloraz against isolates collected in 2006~2007 and 2013~2014 years were 3.125~6.25 μg/mL and 6.25~12.5 μg/mL, respectively. The mean EC50 value of isolates increased from 0.3142 μg/mL in 2006~2007 to 0.8124 μg/mL in 2013~2014. Based on the EC50 value of isolates collected in 2006~2007, the resistant baseline of prochloraz was determined as 0.6 μg/mL. Compared with the ratio of resistant isolates in 2006~2007, the ratio of resistant isolates in 2013~2014 increased from 6.5% to 41.6%.

Acknowledgements

This study was supported by a grant (Project No. PJ00 9891) from Rural Development Administration, Republic of Korea.

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