Genotypic Diversity and Resistance to Azoxystrobin ofCercospora beticolaon Processing Table Beet in New York

• DOI: 10.1094/pdis-09-15-1014-re
• Publication Date: 2016-01-13T04:21:28Z
• Authors: Niloofar Vaghefi; Frank S. Hay; Julie R. Kikkert; Sarah J. Pethybridge
• Keywords: Cercospora

Cercospora leaf spot (CLS), caused by beticola, is one of the major diseases affecting productivity and profitability beet production worldwide. Fungicides are critical for control this disease most commonly used products quinone outside inhibitor (QOI) azoxystrobin. In total, 150 C. beticola isolates were collected from two commercial processing table fields in Batavia, NY 2014. The mating types entire population determined, genetic diversity a subset samples (n = 48) was assessed using five microsatellite loci. Sensitivity to azoxystrobin tested spore germination assay. cytochrome b gene sequenced check presence point mutations known confer QOI resistance fungi. High allelic (He 0.50) genotypic (D* 0.96), gametic equilibrium loci, equal ratios suggestive mixed mode reproduction beticola. Resistance prevalent because 41% had values effective concentrations reducing 50% (EC50) > 0.2 μg/ml. G143A mutation, cause found with EC50 between 0.207 19.397 A single isolate an 0.272 μg/ml carried F129L be associated low levels This first report mutation implications these findings epidemiology CLS New York discussed.