Korean Journal of Mycology (Kor. J. Mycol.)
Indexed in SCOPUS, KCI, DOAJ
OPEN ACCESS, PEER REVIEWED
pISSN 0253-651X
eISSN 2383-5249

Fungicide Resistance of Gibberella fujikuroi Isolates Causing Rice Bakanae Disease and Their Progeny Isolates

1Korea National College of Agriculture and Fisheries, Hwasung, 445-893, Korea
2Crop Protection Division, National Academy of Agricultural Science, RDA, Suwon 441-707, Korea
3Department of Agricultural Biology, Chungnam National University, Daejeon, Korea

Correspondence to hyon338@korea.kr

Korean Journal of Mycology (Kor J Mycol) June 30, 2010, 38(1):75-79.
https://doi.org/10.4489/kjm.2010.38.1.075
(Received June 22, 2010. Accepted June 23, 2010)
Published: June 30, 2010.
© The Korean Society of Mycology

ABSTRACT

A total of 25 isolates of Fusarium fujikuroi were obtained from diseased rice plants in Korea from 2006 to 2007 to assess their resistance against fungicides prochloraz and benomyl + thiram. Minimal inhibitory concentration (MIC) values of F. fujikuroi isolates were examined by agar dilution method. Most of the isolates were sensitive to the fungicides. Out of 25 isolates, six were resistant to prochloraz and three to benomyl + thiram. In addition, the isolates CF245, CF249 and CF337 showed resistant to both fungicides. The progenies (F1 isolates) obtained through two different crosses between sensitive parental isolates(CF202, CF232 and CF179) and resistant parental isolate (CF337) were evaluated for their mycelial growth at different temperatures and resistance against fungicides. Mycelial growth rate of F1 isolates originated from CF202 × CF232 was similar to the parental isolates. However mycelial growth rate of F1 isolates originated from CF179 × CF337 was faster than their parent isolates. In case of prochloraz, distribution ratio of sensitivity(S) to resistance(R) against to the fungicide of F1 isolates originated from CF202 × CF232 and CF179 × CF337 was 86 : 14 and 78 : 22, respectively. In case of benomyl+thiram, all the F1 isolates originated from CF202 × CF232 were sensitive to the fungicide, however ratio of sensitivity(S) to resistance(R) against to the fungicide of F1 isolates originated from CF179 × CF337 was 35 : 65.

Keywords

Bakanae disease, Benomyl + thiram, Fungicide resistance, Fusarium fujikuroi, Prochloraz

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