Iowa State University, Plant Pathology and Microbiology, Ames, IA.
USDA-ARS, National Center for Agricultural Utilization Research, Peoria, IL.
Plant Dis. 2018 Feb;102(2):282-291. doi: 10.1094/PDIS-01-17-0103-RE. Epub 2017 Nov 21.
Species of Aspergillus section Nigri are commonly associated with maize kernels, and some strains can produce fumonisin mycotoxins. However, there is little information about the extent to which these fungi contribute to fumonisin contamination in grain, the damage they cause to maize ears, or their effects on maize seed germination and seedling health. We compared fumonisin-producing and nonproducing strains of A. niger, A. welwitschiae, A. phoenicis, A. tubingensis, and A. carbonarius from the United States and Italy in laboratory and field studies to assess their ability to contribute to fumonisin contamination, to cause maize ear rot, and to affect seed germination and seedling growth. In laboratory experiments, some strains of each Aspergillus species reduced germination or seedling growth, but there was high variability among strains within species. There were no consistent differences between fumonisin-producing and nonproducing strains. In field studies in Iowa and Illinois, strains were variable in their ability to cause ear rot symptoms, but this was independent of the ability of the Aspergillus strains to produce fumonisins. Contamination of grain with fumonisins was not consistently increased by inoculation with Aspergillus strains compared with the control, and was much greater in F. verticillioides-inoculated treatments than in Aspergillus-inoculated treatments. However, the ratio of the FB analogs FB and FB was altered by inoculation with some Aspergillus strains, indicating that FB production by Aspergillus strains occurred in the field. These results demonstrate the pathogenic capabilities of strains of Aspergillus in section Nigri, but suggest that their effects on maize ears and seedlings are not related to their ability to produce fumonisins, and that fumonisin contamination of grain caused by Aspergillus spp. is not as significant as that caused by Fusarium spp.
黑曲霉节的曲霉物种通常与玉米籽粒有关，有些菌株可以产生伏马菌素真菌毒素。然而，关于这些真菌在谷物中伏马菌素污染的程度、它们对玉米穗的损害以及它们对玉米种子萌发和幼苗健康的影响，知之甚少。我们比较了来自美国和意大利的黑曲霉、威氏曲霉、黄曲霉、突脐曲霉和炭黑曲霉的产伏马菌素和非产伏马菌素菌株，在实验室和田间研究中评估它们对伏马菌素污染的贡献能力、引起玉米穗腐病的能力以及影响种子萌发和幼苗生长的能力。在实验室实验中，一些曲霉物种的菌株降低了萌发或幼苗生长，但种内菌株间存在高度变异性。产伏马菌素和非产伏马菌素菌株之间没有一致的差异。在爱荷华州和伊利诺伊州的田间研究中，菌株引起穗腐症状的能力存在差异，但这与曲霉菌株产生伏马菌素的能力无关。与对照相比，用曲霉菌株接种并未一致增加谷物中伏马菌素的污染，而与曲霉菌株接种相比，用黄曲霉接种处理的污染程度要大得多。然而，一些曲霉菌株的接种改变了 FB 类似物 FB 和 FB 的比例，表明 FB 是由曲霉菌株在田间产生的。这些结果表明了黑曲霉节中曲霉菌株的致病性能力，但表明它们对玉米穗和幼苗的影响与其产生伏马菌素的能力无关，并且由曲霉属引起的谷物伏马菌素污染并不像由镰刀菌属引起的那样显著。
