Gachango E, Hanson L E, Rojas A, Hao J J, Kirk W W
Department of Plant Pathology.
Department of Plant Pathology and United States Department of Agriculture-Agricultural Research Service.
Plant Dis. 2012 Dec;96(12):1767-1774. doi: 10.1094/PDIS-11-11-0932-RE.
A survey of seed potato tubers in Michigan seed production storage facilities was carried out during 2009 and 2010. Fusarium spp. associated with tuber dry rot symptoms were identified to species and tested for sensitivity to difenoconazole, fludioxonil, and thiabendazole. Symptomatic tubers (n = 370) were collected from a total of 51 seed lots, from which 228 isolates of Fusarium were recovered and identified to 11 species. Fusarium oxysporum was the most commonly isolated species (30.3%), followed by F. equiseti (19.3%). F. sambucinum and F. avenaceum were third most prevalent (each at 13.6%). Less prevalent species (each at 4 to 10%) included F. cerealis, F. solani, and F. acuminatum; and species present at ≤3% included F. sporotrichioides, F. torulosum, F. tricinctum, and F. graminearum. Representative isolates of all species were pathogenic when inoculated onto seed tubers ('Dark Red Norland'). Isolates of F. sambucinum were the most virulent. All 228 isolates of Fusarium were sensitive to difenoconazole (effective fungicide concentration that caused 50% inhibition of mycelial growth [EC] < 5 mg/liter). Insensitivity to fludioxonil (EC > 100 mg/liter) was detected only for F. sambucinum and F. oxysporum isolates at 8.9 and 20.4%, respectively. All isolates were sensitive to thiabendazole (EC < 5 mg/liter), except for those of F. sambucinum (EC > 100 mg/liter). Therefore, knowledge of what Fusarium spp. are present in seed potato storage facilities in Michigan may be important if using fludioxonil or thiabendazole for seed piece treatment but not when using difenoconazole.
2009年至2010年期间，对密歇根州种薯生产储存设施中的种薯块茎进行了一项调查。对与块茎干腐症状相关的镰刀菌属进行了种的鉴定，并测试了其对苯醚甲环唑、咯菌腈和噻菌灵的敏感性。从总共51个种薯批次中收集了有症状的块茎（n = 370），从中分离并鉴定出228株镰刀菌，分属于11个种。尖孢镰刀菌是最常分离到的种（30.3%），其次是木贼镰刀菌（19.3%）。接骨木镰刀菌和燕麦镰刀菌并列第三（均为13.6%）。较不常见的种（均为4%至10%）包括禾谷镰刀菌、茄病镰刀菌和锐顶镰刀菌；存在比例≤3%的种包括拟枝孢镰刀菌、串珠镰刀菌、三线镰刀菌和禾谷镰刀菌。将所有种的代表性分离株接种到种薯块茎（“深红诺兰德”）上时均具有致病性。接骨木镰刀菌的分离株毒性最强。所有228株镰刀菌分离株对苯醚甲环唑均敏感（引起50%菌丝生长抑制的有效杀菌剂浓度[EC]<5毫克/升）。仅检测到接骨木镰刀菌和尖孢镰刀菌的分离株对咯菌腈不敏感（EC>100毫克/升），比例分别为8.9%和20.4%。除接骨木镰刀菌的分离株（EC>100毫克/升）外，所有分离株对噻菌灵均敏感（EC<5毫克/升）。因此，如果使用咯菌腈或噻菌灵进行种薯处理，了解密歇根州种薯储存设施中存在哪些镰刀菌属可能很重要，但使用苯醚甲环唑时则不然。
