Molecular identification of fungal isolates from different tissues samples of Blueberry (Vaccinum sp) in Baja California

Abstract

Objective: Molecular identification of fungal isolates presents in fruits and leaf samples of Vaccinium with pathogenic or agro-industrial potential Design/methodology/approach: Plant material (fruits and leaves) was collected in blueberry commercial plantations of San Quintin, Baja California, México. The samples were placed in humid chambers for fungal growth and then in culture plates with Potato-Dextrose-Agar alone or with lactic acid for purification. The resulting fungal isolates were cultured in liquid media, the total DNA was extracted and quantified, afterwards the ITS region was amplified by PCR, the fragments were purified and sequenced. Finally, the resulting sequences were compared in the NCBI database with the BLAST algorithm, the phylogenetic reconstruction was performed with the MEGA (v.10.0) software. Results: A total of 22 isolates from Vaccinium were obtained from leaves and fruits. These isolates showed high identity percentages (96-100 %) with Botrytis, Didymella, Phoma, Alternaria and Cladosporium genera. The fruit isolates were closely related with B. cinerea Group I, whereas the leaf samples grouped with other complexes such as the C. cladosporoides, A. muriae, Dydimella bervipilosa and Phoma. Limitations on study/implications: The use of the ITS region provides only a partial characterization in some types of fungi, the use of other molecular markers are required to fully characterize some isolates. Findings/conclusions: The molecular characterization of the fungal isolates showed that most of the genera were saprophytes with phytopathogenic members reported. The reported genera could have an impact in post-harvest due fruit spoilage or by the presence of cytotoxic compounds. The presence of fungal genera (Cladosporium) with reported potential antagonistic and growth promoting capabilities was identified.