Laboratoire de Protection des végétaux, Institut National de la Recherche Agronomique de Tunis, rue Hédi Karray, 2049, Tunisia.
Int J Food Microbiol. 2010 May 30;140(1):84-9. doi: 10.1016/j.ijfoodmicro.2010.01.040. Epub 2010 Feb 4.
Fusarium culmorum is a major pathogen associated with Fusarium head blight (FHB) of wheat in Tunisia. It may cause yield loss or produce mycotoxins in the grain. The objectives of the present study were threefold: to evaluate by PCR assays the type of mycotoxins produced by 100 F. culmorum isolates recovered from different regions in Northern Tunisia, to determine the amount of mycotoxin production by HPLC analysis, and to analyse for correlations between the amount of mycotoxin produced and the aggressiveness of isolates. PCR assays of Tri5, Tri7, Tri13, and Tri3 were used to predict whether these isolates could produce nivalenol, 3-acetyl-deoxynivalenol, or 15-acetyl-deoxynivalenol. Two of the isolates were predicted to produce NIV, whereas the others were predicted to produce 3-AcDON. Trichothecene production was confirmed and quantified by high pressure liquid chromatography (HPLC) in 28 isolates, after growth on wheat grains, and in a liquid Mycotoxin Synthetic medium (MS). All strains produced DON/3-AcDON at detectable levels ranging from 21 microg/g to 11.000 microg/g of dry biomass on MS medium and from 10 microg/g to 610 microg/g on wheat grain. The evaluation of the relationship between 3-AcDON production and aggressiveness of 17 strains revealed a significant difference in aggressiveness among the isolates. Moreover, only a significant correlation was revealed between aggressiveness and the amount of 3-AcDON produced on MS medium (r=0.36). Chemotyping of F. culmorum isolates is reported for the first time for isolates from Tunisia, and highlights the important potential of F. culmorum to contaminate wheat with 3-AcDON trichothecenes.
镰刀菌禾谷孢是突尼斯小麦赤霉病（FHB）的主要病原体。它可能导致减产或在谷物中产生霉菌毒素。本研究的目的有三个：通过 PCR 检测 100 株从突尼斯北部不同地区分离到的镰刀菌禾谷孢产生的霉菌毒素类型，通过 HPLC 分析确定霉菌毒素的产生量，并分析产生的霉菌毒素量与分离物的侵袭力之间的相关性。使用 Tri5、Tri7、Tri13 和 Tri3 的 PCR 检测来预测这些分离物是否能够产生雪腐镰刀菌烯醇、3-乙酰脱氧雪腐镰刀菌烯醇或 15-乙酰脱氧雪腐镰刀菌烯醇。有两个分离物被预测会产生 NIV，而其他分离物被预测会产生 3-AcDON。通过高压液相色谱（HPLC）在 28 个分离物中证实并定量了赤霉烯酮的产生，这些分离物在麦粒上生长后以及在液体霉菌毒素合成培养基（MS）中培养后。所有菌株在 MS 培养基上均以可检测水平产生 DON/3-AcDON，浓度范围为 21μg/g 至 11000μg/g 干生物量，在麦粒上产生 10μg/g 至 610μg/g。对 17 个菌株的 3-AcDON 产生与侵袭力之间关系的评估表明，分离物之间的侵袭力存在显著差异。此外，仅在 MS 培养基上 3-AcDON 产生量与侵袭力之间显示出显著相关性（r=0.36）。这是首次对来自突尼斯的镰刀菌禾谷孢分离物进行化学型分析，突出了镰刀菌禾谷孢对小麦污染 3-AcDON 赤霉烯酮的重要潜力。
