Wilt disease complex is one of the most important diseases of tomatillo (Physalis ixocarpa) in the production areas of Mexico. Disease symptoms include wilting, poor growth, discoloration of vascular tissues, root rot, and death of plants. The aims of this study were to identify the fungi associated with wilt disease complex of tomatillo by the combination of phylogenetic analyses and morphological characterization, as well as to determine their pathogenicity and virulence on tomatillo seedlings. A total of 88 fungal isolates were obtained from symptomatic plants from 19 tomatillo fields distributed in northern Sinaloa, Mexico. Subsequently, a subset of 37 isolates representing the range of geographic origin was selected for further morphological and molecular characterization as well as pathogenicity tests. Phylogenetic analyses using Maximum Likelihood were used to identify 15 isolates of Rhizoctonia (ITS sequence data), 14 isolates of Fusarium (EF-1α sequence data), five isolates of Macrophomina (ITS, EF-1α, BT, and ACT sequence dataset) and three isolates of Neocosmospora (EF-1α sequence data) to species level. Pathogenicity tests were performed on tomatillo seedlings (cv. Gran Esmeralda) under greenhouse conditions. Phylogenetic analyses of 37 fungal isolates allowed the identification of Rhizoctonia solani AG 4-HGI (40.5%), Fusarium oxysporum (29.8%), Macrophomina phaseolina (13.5%), F. nygamai (8.1%) and Neocosmospora falciformis (8.1%). All fungal species were found to be pathogenic on tomatillo seedlings but a significant difference in disease severity was observed. To our knowledge, F. nygamai, M. phaseolina and N. falciformis were recorded for the first time infecting tomatillo in Mexico and worldwide.

枯萎病综合症是番茄最重要的疾病之一（酸浆）在墨西哥的生产地区。疾病症状包括萎，生长不良，维管组织变色，根腐烂和植物死亡。这项研究的目的是通过系统发育分析和形态学特征的组合，鉴定与番茄枯萎病综合症相关的真菌，并确定其对番茄幼苗的致病性和致病性。从分布在墨西哥北部锡那罗亚州的19个番茄田的有症状植物中获得了总共88种真菌分离株。随后，选择了代表地理起源范围的37个分离株的一个子集，以进行进一步的形态学和分子表征以及致病性测试。用最大似然法进行系统发育分析，鉴定出15种根瘤菌（ITS序列数据），的14株镰刀菌（EF-1α序列数据），的5株Macrophomina（ITS，EF-1α，BT，和ACT序列数据集）和的3株新赤壳（EF-1α序列数据）物种水平。在温室条件下对番茄幼苗（cv。Gran Esmeralda）进行了致病性测试。通过对37种真菌分离株进行系统进化分析，可以鉴定出立枯丝核霉4-HGI（40.5％），尖孢镰刀菌（29.8％），菜豆（Phomophomina phaseolina）（13.5％），念珠镰刀（8.1％）和镰刀菌（8.1％）。发现所有真菌物种在番茄幼苗上均具有致病性，但观察到病害严重程度存在显着差异。据我们所知，墨西哥和全世界首次记录了F. nygamai，M。phaseolina和N. falciformis。