P-401 - Fungal pathogens of hemp in Eastern Pennsylvania

Hemp is a versatile crop that includes varieties for grain, fiber, and flower cannabinoid production. Although these varieties have significant differences in terms of plant structure and growth requirements, they are vulnerable to the same pests and diseases. Annual collections of fungal pathogens causing leaf spots and/or yellowing, or discoloration of flower tissue have been conducted in farms in Bucks County PA to identify the most common threats to these crops since 2023. Symptomatic tissues were collected, surface sterilized and plated on water agar. After one to three days hyphal tips were transferred to PDA and grown for at least 5 days. Contaminated cultures were subcultured until pure cultures were obtained. Pure cultures were examined and transferred to PDB. Mycelia were collected by filtration. DNA was purified using the CTAB protocol. ITS 4 and ITS 5 primers were used to amplify the ITS region of each isolate.  Tentative molecular identification was conducted by comparing the sequences against the NCBI Nucleotide Database using BLAST. Morphological examination was conducted on the isolates once they produced spores. The most frequently fungal species identified included known pathogens of hemp, such as Alternaria spp. and Nigrospora sp. Current work is focused on sequencing additional genetic barcodes to obtain accurate identification of these pathogens, and on the development of e-probe data bases for pathogen identification from metagenomic data.