The incidence of fungi infecting ([Hochst ex. A. Rich.] Harms) commonly known as African yam bean (AYB) were surveyed in Oyo, Ondo, Ekiti, Osun, and Ogun states within SW Nigeria during the 2018 planting season. The common field symptoms across all sites were tiny spot, brown spot, leaf blight, brown spot with yellow halo, necrotic lesion on foliage, and brown spot on the pods. Of these 1005 isolations, 14 fungal species were commonly identified after their purification: sp sp sp sp spp. based on morphological characteristics. sp and had highest frequency of occurrence 69.9% and 51.9% at early and mature stages, respectively. To conform to Koch's postulates, the pathogenicity of 15 exemplar strains of the most abundant fungal species were confirmed under greenhouse conditions. The identities of sp., sp sp sp, , and were confirmed based on internal transcribed spacer (ITS) sequencing and comparisons with the Genbank database. AYB germplasm from curated seed banks and farmer donated landraces were grown at the same site in 2020 and identical fungi were isolated. Further, genotypes with reduced disease incidence were identified. This first study to reveal the diversity of fungi associated with AYB in SW Nigeria that could inform disease management practices.

中文翻译：

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确定非洲山药豆（Sphenostylis stenocarpa）的真菌病害及其在尼日利亚西南部的发病率

2018 年种植季节，对尼日利亚西南部的奥约、翁多、埃基蒂、奥孙和奥贡州的真菌感染（[Hochst ex. A. Rich.] Harms）（俗称非洲豆薯 (AYB)）的发病率进行了调查。各站点常见田间症状为小斑病、褐斑病、叶枯病、黄晕褐斑病、叶面坏死病斑、豆荚褐斑病。在这 1005 个分离物中，纯化后通常鉴定出 14 种真菌： sp sp sp sp sp spp。根据形态特征。sp和在早期和成熟阶段出现频率最高，分别为69.9%和51.9%。为了符合科赫的假设，在温室条件下确认了最丰富的真菌物种的 15 种示例菌株的致病性。基于内转录间隔区 (ITS) 测序和与 Genbank 数据库的比较，确认了 sp.、sp sp、sp、和 的身份。2020 年，来自精心策划的种子库和农民捐赠的地方品种的 AYB 种质在同一地点种植，并分离出相同的真菌。此外，还确定了疾病发病率降低的基因型。这是第一项揭示尼日利亚西南部与 AYB 相关真菌多样性的研究，可为疾病管理实践提供信息。