Morphological and Molecular Characterization of the Fungi Isolated from Infected Wheat Plant

Background: Aspergillus aflatoxiformans, Fusarium humuli and Curvularia geniculata are fungal pathogens of agricultural and clinical significance, associated with crop diseases, mycotoxin production and opportunistic human infections. Accurate identification is essential for understanding their taxonomy, pathogenic potential and ecological roles. Methods: Infected wheat grains and leaves were collected from the Meerut region, India. Fungi were isolated using surface sterilization and cultured on potato dextrose agar. Morphological identification was performed via colony characterization and microscopic examination. Molecular identification was conducted through internal transcribed spacer region amplification, sequencing and BLAST analysis. Phylogenetic relationships and genetic diversity were assessed using Neighbor-Joining and Maximum Composite Likelihood methods. Result: Fusarium spp. exhibited rapid growth with sickle-shaped macroconidia; Aspergillus spp. formed yellow-green, powdery colonies with globose conidia; Curvularia spp. produced dark brown, velvety colonies with geniculate conidia. Internal transcribed spacer sequencing yielded amplicons of 553 bp (Fusarium humuli), 588 bp (Aspergillus aflatoxiformans) and 618 bp (Curvularia geniculata), showing high homology to reference strains (98–100%). Phylogenetic analysis clustered isolates with their respective species, revealing clear genetic distinctiveness and potential regional adaptations. Integration of morphological and internal transcribed spacer-based molecular approaches effectively identified Fusarium humuli, Aspergillus aflatoxiformans and Curvularia geniculata highlighting their pathogenic potential and genetic distinctiveness. These findings underscore the importance of combined diagnostic methods for accurate fungal identification, which is crucial for crop protection, food safety and public health.