Sclerotium delphinii is a common pathogen that causes wilting in a number of plants. In recent years, the genus Sclerotium has been reported as one of those responsible for leaf spots in Piper nigrum in the Amazonian humid tropical regions. In 2017–2018, several black pepper plants presented symptoms of concentric leaf spots. Five isolates were obtained in this study for morphological and phylogenetic characterizations and pathogenicity test. Initially, the gene regions (ITS and LSU) were amplified and sequenced. Phylogenetic analysis confirmed the grouping of the five isolates with the S. delphinii reference isolate (CBS 672.71). The isolates produced sclerotia in all culture media, but some of them altered their capacity to produce sclerotia. The inoculated isolates induced irregular necrotic lesions in the pathogenicity assay using detached leaves. The symptomatic leaves were re-isolated and the fungus culture obtained. No fungus growth was observed in the leaves used as control. This study is the first record of S. delphinii causing leaf spots on P. nigrum in Brazil.

Sclerotium delphinii是一种常见的病原体，会导致许多植物枯萎。近年来，据报道菌核属是造成亚马逊潮湿热带地区黑胡椒叶斑病的原因之一。2017-2018 年，几种黑胡椒植株出现同心叶斑病症状。在这项研究中获得了五个分离株，用于形态学和系统发育特征以及致病性测试。最初，基因区域（ITS 和 LSU）被扩增和测序。系统发育分析证实了五个分离株与S. delphinii的分组参考分离株 (CBS 672.71)。这些分离株在所有培养基中都能产生菌核，但其中一些会改变它们产生菌核的能力。在使用离体叶子的致病性测定中，接种的分离株诱导了不规则的坏死病变。重新分离有症状的叶子并获得真菌培养物。在用作对照的叶子中没有观察到真菌生长。这项研究是第一次在巴西的P. nigrum上引起S. delphinii叶斑的记录。