Optimal liquid-based DNA preservation for DNA barcoding of field-collected fungal specimens

Preserving fungal tissue DNA in the field is essential for molecular ecological research, enabling the study of fungal biodiversity and community dynamics. This study systematically compares two liquid-based preservation solutions, RNAlater and DESS, for their effectiveness in maintaining macrofungi DNA integrity during field collection and storage. The research encompasses both controlled experiments and real-world field collections. In the controlled experiments, two fungal species were preserved in RNAlater and DESS at different temperatures and durations. DNA extraction success rates were high, but DNA quality and quantity metrics exhibited variations across samples. However, both preservation solutions demonstrated their viability for preserving fungal DNA, with no significant differences between them. In the field-collected macrofungi experiment, 160 paired fungal specimens were preserved in RNAlater and DESS, respectively. Including a drying process to facilitate tissue lysis for DNA extraction significantly impacted the outcomes. RNAlater showed a higher success rate and better DNA quality and quantity compared to DESS. Statistical analysis, including paired and independent t-tests, confirmed significant differences in DNA quality and quantity between the two preservation methods for field-collected samples. This study evaluates RNAlater and DESS for preserving macrofungi DNA in field conditions. Both methods are effective, but RNAlater is superior when a drying step is included in DNA extraction. Researchers can choose based on their specific needs without compromising DNA integrity. These findings advance fungal molecular ecology and DNA preservation strategies in ecological and environmental studies.