Field bindweed (Convolvulus arvensis L.) has been described as one of the most noxious weeds in agricultural soils worldwide. Furthermore, its control by conventional herbicides can promote the emergence of resistant biotypes as well as negatively affect human health and the environment. An ecological alternative for weed management is the use of phytopathogenic fungi. In this study, 68 fungal strains were isolated from C. arvensis leaves exhibiting symptoms of fungal disease. Seven isolates were confirmed as pathogenic to C. arvensis in a detached leaf assay. Filtered cell-free cultures (FCFC) of these seven isolates were then evaluated. FCFC of TV1 and ET4 showed the best results, inhibiting seedling dry weight by up to 48% in vivo and shoot dry weight up to 35% in growth chamber assays. Phytopathogenic evaluation of both isolates showed disease severity >67%, and an ability to inhibit root dry weight by up to 80%. Inhibitory effects were not observed on chickpea, bean, sorghum, maize, or tomato plants, suggesting pathogenic specificity of TV1 and ET4 to field bindweed. Molecular identification revealed a high similarity of TV1 (100% identity) with Macrophomina phaseolina, and a high similarity of ET4 with Alternaria alternata (99.8% identity). To the best of our knowledge, this is the first report of M. phaseolina showing pathogenicity against field bindweed worldwide, and the first report for A. alternata in Mexico. The results reveal that these fungi and/or their FCFC have the potential to be used as bioherbicidal agents against C. arvensis.

中文翻译：

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具有生物除草剂潜力的植物病原真菌的分离、选择和鉴定，用于控制田间旋花（Convolvulus arvensis L.）

田间旋花（Convolvulus arvensis L.）被描述为全世界农业土壤中最有害的杂草之一。此外，传统除草剂对其的控制会促进抗药性生物型的出现，并对人类健康和环境产生负面影响。杂草管理的生态替代方案是使用植物病原真菌。在这项研究中，从表现出真菌病症状的C. arvensis叶子中分离出 68 株真菌菌株。在离体叶测定中，7 个分离株被证实对C. arvensis具有致病性。然后评估这七种分离株的过滤无细胞培养物（FCFC）。TV1 和 ET4 的 FCFC 显示出最好的结果，在体内抑制幼苗干重高达 48%，在生长室测定中抑制芽干重高达 35%。对两种分离株的植物病原性评估显示，疾病严重程度 >67%，并且能够抑制根干重高达 80%。在鹰嘴豆、豆类、高粱、玉米或番茄植物上未观察到抑制作用，表明 TV1 和 ET4 对田间旋花具有致病特异性。分子鉴定显示TV1与Macrophhomina Phaseolina高度相似(100%同一性) ，ET4与Alternaria alternata高度相似(99.8%同一性)。据我们所知，这是世界范围内首次报告M. Phaseolina对田间旋花具有致病性，也是墨西哥的第一份关于A. alternata 的报告。结果表明，这些真菌和/或其 FCFC 有潜力用作针对C. arvensis 的生物除草剂。