Plant Protection Department, Faculty of Agriculture, University of Bu-Ali Sina, P. O. Box: 6517833131, Hamedan, Iran.
Plant Protection Department, Faculty of Agriculture, University of Bu-Ali Sina, P. O. Box: 6517833131, Hamedan, Iran.
Chemosphere. 2022 Mar;291(Pt 3):133061. doi: 10.1016/j.chemosphere.2021.133061. Epub 2021 Nov 25.
Application of fungal phytotoxins is one of the possible solutions to reduce the use of chemical products in agricultural fields. Phytotoxic compounds isolated from phytopathogenic fungi provide a promising source of environmentally friendly herbicides. This paper focuses on the phytotoxic fungus Coniolariella gamsii Iran 2506C as a fungal pathogen against Iranian knapweed (Centaurea depressa) in the western Iran and investigate its phytotoxic constituents. The fungal pathogen was identified on the basis of morphological characteristics and confirmed by sequencing of the internal transcribed spacer (ITS) region and partial LSU rDNA gene. Pathogenicity tests were conducted on the weed seedlings and C. gamsii Iran 2506C isolate with high disease severity was selected for phytotoxin studies. Phytotoxic activity of the isolate was checked by screening the production of phytotoxins, which interestingly inhibited seed germination and seedling growth of Iranian knapweed as compared to wheat in the bioassays. The active metabolites were extracted from cell-free culture filtrate (CFCF) by ethyl acetate and separated by thin layer chromatography (TLC). The results indicated that two out of four spots had phytotoxicity with R values of 0.43 and 0.82 on the weed, whereas wheat was not sensitive in the bioassays. Using Gas Chromatography-Mass spectrometry (GC-MS), 3-Carene and Oleic acid were identified as the main constituents and quantified by a gas chromatographic method with 12.7 ± 0.03 and 2.9 ± 0.01 μg ml respectively. This is the first finding presented on the phytotoxic effects of the active metabolites of C. gamsii Iran 2506C and highlights its herbicidal potential which can be used as a biocontrol agent of C. depressa.
真菌毒素的应用是减少农业领域化学产品使用的可能解决方案之一。从植物病原菌中分离出的植物毒性化合物为环保型除草剂提供了有前途的来源。本文重点研究了真菌病原菌 Coniolariella gamsii Iran 2506C，它是伊朗西部地区一种针对伊朗矢车菊（Centaurea depressa）的真菌病原体，并研究了其植物毒性成分。该真菌病原体是根据形态特征鉴定的，并通过内部转录间隔区（ITS）区域和部分 LSU rDNA 基因的测序得到确认。对杂草幼苗进行了致病性试验，选择具有高疾病严重程度的真菌病原体 C. gamsii Iran 2506C 分离株进行植物毒素研究。通过筛选植物毒素的产生来检查分离株的植物毒性活性，有趣的是，与小麦相比，生物测定中分离株抑制了伊朗矢车菊的种子萌发和幼苗生长。通过乙酸乙酯从无细胞培养滤液（CFCF）中提取活性代谢物，并通过薄层层析（TLC）进行分离。结果表明，在杂草上有四个斑点中的两个具有植物毒性，其 R 值分别为 0.43 和 0.82，而小麦在生物测定中不敏感。使用气相色谱-质谱（GC-MS），鉴定出 3-蒈烯和油酸为主要成分，并通过气相色谱法分别定量为 12.7±0.03μg/ml 和 2.9±0.01μg/ml。这是首次报道 C. gamsii Iran 2506C 的活性代谢物的植物毒性作用，并强调了其除草潜力，可作为 C. depressa 的生物防治剂。
