caa a22 4500 467890978 CHVBK 20180406152749.0 cr unu---uuuuu 170328e20061001xx s 000 0 eng 10.1007/s10327-006-0285-9 doi (NATIONALLICENCE)springer-10.1007/s10327-006-0285-9 Effects of thiophanate-methyl and azoxystrobin on the composition of Cercospora kikuchii populations with thiophanate-methyl-resistant strains [Elektronische Daten] [Iori Imazaki, Hiromi Iizumi, Kouji Ishikawa, Masashi Sasahara, Nobuko Yasuda, Shinzo Koizumi] Azoxystrobin was recently registered in Japan for the control of purple seed stain of soybean caused by Cercospora kikuchii, because the pathogen has developed resistance to thiophanate-methyl. To investigate the effects of these fungicides on the frequency of C. kikuchii strains resistant to thiophanate-methyl and on the genotype structure of the population, we sowed purple-stained seeds, approximately 40% of which were infected with resistant strains, as inocula with asymptomatic seeds and applied thiophanate-methyl and azoxystrobin during the reproductive growth of soybeans. The isolation frequency of resistant strains increased more than 99% by thiophanate-methyl but was not significantly increased by azoxystrobin. In amplified fragment length polymorphism (AFLP) DNA fingerprinting, genotypic diversity was significantly decreased by thiophanate-methyl but was not affected by azoxystrobin. In addition, the similarity of the AFLP genotype structure was increased by thiophanate-methyl but not by azoxystrobin. These results suggest that thiophanate-methyl selectively inhibited the proliferation of sensitive strains, which resulted in a small number of genotypes, most of which were resistant strains. Azoxystrobin was found to nonselectively inhibit proliferation of the pathogen, which retained a large number of genotypes including thiophanate-methyl-sensitive or thiophanate-methyl-resistant strains or both. The Phytopathological Society of Japan and Springer-Verlag Tokyo, 2006 Thiophanate-methyl nationallicence Azoxystrobin nationallicence Cercospora kikuchii nationallicence Genotypic diversity nationallicence Imazaki Iori National Agricultural Research Center, 3-1-1 Kannondai, 305-8666, Tsukuba, Japan aut Iizumi Hiromi National Agricultural Research Center, 3-1-1 Kannondai, 305-8666, Tsukuba, Japan aut Ishikawa Kouji National Agricultural Research Center, 3-1-1 Kannondai, 305-8666, Tsukuba, Japan aut Sasahara Masashi Crop Research Center, Niigata Agricultural Research Institute, Nagaoka, Japan aut Yasuda Nobuko Miyagi Prefecture Furukawa Agricultural Experiment Station, Furukawa, Japan aut Koizumi Shinzo National Agricultural Research Center for Tohoku Region, Daisen, Japan aut Journal of General Plant Pathology Springer-Verlag 72/5(2006-10-01), 292-300 1345-2630 72:5<292 2006 72 10327 https://doi.org/10.1007/s10327-006-0285-9 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s10327-006-0285-9 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Imazaki Iori National Agricultural Research Center, 3-1-1 Kannondai, 305-8666, Tsukuba, Japan aut NATIONALLICENCE 700 1- Iizumi Hiromi National Agricultural Research Center, 3-1-1 Kannondai, 305-8666, Tsukuba, Japan aut NATIONALLICENCE 700 1- Ishikawa Kouji National Agricultural Research Center, 3-1-1 Kannondai, 305-8666, Tsukuba, Japan aut NATIONALLICENCE 700 1- Sasahara Masashi Crop Research Center, Niigata Agricultural Research Institute, Nagaoka, Japan aut NATIONALLICENCE 700 1- Yasuda Nobuko Miyagi Prefecture Furukawa Agricultural Experiment Station, Furukawa, Japan aut NATIONALLICENCE 700 1- Koizumi Shinzo National Agricultural Research Center for Tohoku Region, Daisen, Japan aut NATIONALLICENCE 773 0- Journal of General Plant Pathology Springer-Verlag 72/5(2006-10-01), 292-300 1345-2630 72:5<292 2006 72 10327 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer