Diversity of Fungi Associated with Diseases of Cultivated Brassicaceae in Southern Italy

This study investigated the fungal species associated with symptomatic cultivated Brassica crops in Apulia, Southern Italy, during the 2022-2023 growing seasons. Twenty-two samples from <i>Brassica oleracea</i> var. <i>botrytis</i>, <i>B. oleracea</i> var. <i>italica</i>, and <i>B. rapa</i> var. <i>cymosa</i> showing stunting, wilting, necrotic spots, and lesions were analyzed using morphological and molecular analyses. A total of 259 fungal isolates were obtained, mainly belonging to the genera <i>Alternaria</i>, <i>Plectosphaerella</i>, <i>Fusarium</i>, and <i>Sclerotinia</i>, with <i>Alternaria</i> and <i>Plectosphaerella</i> being the most frequent. Microsatellite PCR (MSP-PCR) profiling revealed considerable genetic diversity within the <i>Alternaria</i> and <i>Plectosphaerella</i> genera, whereas <i>Fusarium</i> and <i>Sclerotinia</i> showed uniform profiles. Multilocus analyses (ITS, <i>tef-1α</i>, <i>rpb2</i>, Alt-a1, and <i>gapdh</i>) identified nine species as <i>Alternaria alternata</i>, <i>A. brassicicola</i>, <i>A. japonica</i>, <i>Fusarium solani</i> species complex, <i>Plectosphaerella cucumerina</i>, <i>P. pauciseptata</i>, <i>P. plurivora</i>, <i>Sclerotinia sclerotiorum</i>, and <i>Stemphylium vesicarium</i>. While <i>Alternaria</i>, <i>Fusarium</i>, and <i>Sclerotinia</i> species are well-known Brassicaceae pathogens, <i>P. pauciseptata</i>, <i>P. plurivora</i>, and <i>S. vesicarium</i> have been detected here for the first time on cultivated Brassica crops worldwide. These findings highlight significant intraspecific diversity among the detected fungi and expand the current knowledge of fungal diversity associated with symptomatic cultivated Brassica plants.