中文摘要：赤霉病（FHB）是小粒谷物的一种重要病害，主要由禾谷镰刀菌复合菌(FGSC)成员引起。巴西大麦种植户主要使用杀菌剂，特别是三唑，来控制病害及减少霉菌毒素污染籽粒。大麦FHB病原菌之间对三唑敏感性的资料有限，而通常与大麦FHB相关的FGSC种类之间敏感度等级是否不同尚不明确。为解决该问题，本文于2011年从巴西里奥格兰德州北部21个市镇的商业领域采集了五个品种的大麦籽粒样品进行研究，其结果对评估大麦的霉菌毒素风险及开发有效的管理措施都很重要。
外文摘要：Fusarium head blight (FHB) is an important disease of small grains and is caused mainly by members of the Fusarium graminearum species complex (FGSC). Barley growers in Brazil rely on fungicide application, especially triazoles, to suppress the disease and limit mycotoxin contamination of grain. Information on triazole sensitivity among FHB pathogens from barley is limited and it is unclear whether sensitivity levels differ among species within commonly associated with FHB of barley. To address these questions, grain samples of five barley cultivars were obtained from commercial fields at 21 municipalities in northern Rio Grande do Sul state, Brazil, during 2011 season. The incidence of FGSC was evaluated and the species identity and trichothecene genotypes of FGSC isolates were determined using a multilocus genotype assay. Sensitivity to tebuconazole and metconazole was determined based on the effective concentration that reduced 50% of the mycelial growth (EC50) on agar-based media amended with increasing fungicide dosages (0, 0.1, 0.5, 1.0 and 5.0 μg a.i./ml). FGSC-like colonies were detected in 75% of samples at relatively low mean incidence (3.3%). Among 65 FGSC isolates, three species were found: Fusarium graminearum with the 15-acetyl(A)deoxnyvalenol(DON) genotype was the most common (48 isolates) followed by F. meridionale (16 isolates) with the nivalenol (NIV) genotype and one F. austroamericanum isolate with the 3-ADON genotype. Species composition appeared to be influenced by barley cultivar (P = 0.002), with F. meridionale prevailing in MN743 and MN620 and F. graminearum in BRS Cauê and BRS Elis. Overall, FGSC isolates were around 4 × less sensitive to tebuconazole (mean = 0.773 μg/ml) compared to metconazole (mean = 0.136 μg/ml). F. graminearum isolates were less sensitive than F. meridionale to tebuconazole, but both were similarly sensitive to metconazole. These results are important to both risk assessment of mycotoxins in barley and the deployment of effective management strategies.
外文关键词：Hordeum Vulgare；Gibberella zeae；Fusarium head blight；Fungicide resistance
作者：Machado, FJ；Nicolli, CP；Moller, PA；Arruda, R；Ward, TJ；Del Ponte, EM
作者单位：Univ Fed Vicosa
期刊名称：TROPICAL PLANT PATHOLOGY
期刊影响因子：0.835
出版年份：2017
出版刊次：3
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