Unraveling the Diversity and Pathogenicity of Botryosphaeriales Species Causing Stem Blight and Dieback of Blueberries in Sinaloa, Mexico

Stem blight and dieback of blueberry caused by Botryosphaeriales species is a significant disease worldwide. In Sinaloa, Mexico, stem blight and dieback symptoms are commonly observed in commercial blueberry fields. Therefore, this study aimed to identify the Botryosphaeriales species responsible for disease symptoms in blueberry plants in Sinaloa, Mexico, through a combination of phylogenetic, morphological, and pathogenic approaches. For this, symptomatic samples were collected from plants in 15 commercial fields located in the municipalities of Culiacán, Navolato, El Fuerte, Ahome, and Guasave in the state of Sinaloa, Mexico. Fungal isolations were carried out from the symptomatic tissues, and 105 isolates with typical characteristics of Botryosphaeriales members were purified and preserved. A total of 24 isolates were selected for morphological, phylogenetic (ITS, <i>tef1-α</i>, and <i>tub2</i>), and pathogenic analyses. The phylogenetic inference revealed six species of the Botryosphaeriaceae family, <i>Lasiodiplodia brasiliense</i>, <i>L</i>. <i>subglobosa</i>, <i>L</i>. <i>theobromae</i>, <i>Neofusicoccum brasiliense</i>, <i>N</i>. <i>kwambonambiense</i>, and <i>Cophinforma tumefaciens</i>, as well as <i>Pseudofusicoccum stromaticum</i>, which belongs to the Pseudofusicoccaceae family. In the pathogenicity test, all the isolates induced stem blight symptoms on blueberry branches inoculated with mycelial plugs. <i>Lasiodiplodia</i> spp. isolates were the most aggressive, followed by <i>P</i>. <i>stromaticum</i>, <i>C</i>. <i>tumefaciens</i>, and <i>Neofusicoccum</i> spp. Furthermore, the aggressiveness among the isolates of the different species was significantly different. This study represents the first association of the genera <i>Cophinforma</i> and <i>Pseudofusicoccum</i>, as well as the species <i>L</i>. <i>brasiliense</i>, <i>L</i>. <i>subglobosa</i>, and <i>N</i>. <i>brasiliense</i>, causing stem blight and dieback of blueberry worldwide and provides a basis for initiating research on the integrated management of this complex disease in Sinaloa, Mexico.