Surface-Level Disinfestation Techniques and Their Effect on DNA Sampling: Insight Gained from a Study on Detecting Fusarium graminearum in Hemp ( Cannabis sativa ) using qPCR

Pathogen detection in plant tissue (endophytes, non-culturable pathogens, or asymptomatic/latent infection or colonization) using molecular approaches involves surface disinfestation of samples to remove surface contaminants. The effect of these disinfestation methods on target DNA is unknown. The objectives of this study were to compare the efficacy of surface disinfestation methods and to investigate whether they compromised the integrity of target DNA. Surface disinfestation treatments included 9 solution-duration combinations: 3 disinfestation solutions (70% ethanol [EtOH], 0.83% sodium hypochlorite [NaOCl; 10% bleach], and autoclaved deionized water) and 3 durations (1-, 3-, and 5-minutes). Artificially surface-contaminated hemp flowers infested with F. graminearum were subjected to disinfestation treatments to investigate their efficacy in eliminating surface contaminants. Additionally, F. graminearum infected hemp flowers were subjected to disinfestation treatments to investigate the effects of treatments on the integrity of DNA of F. graminearum within infected hemp flowers. All disinfestation treatments eliminated surface contaminants ( F. graminearum ) on hemp flower tissues without compromising DNA detection via qPCR. Findings of this study can provide standard protocols for surface disinfestation for use in combination with nucleic acid-based pathogen detection methods. This study also encourages further investigation to evaluate the effect of surface disinfestation treatments on DNA integrity in other plant or plant tissue types.