Postharvest storage conditions impact potato tuber microbiome and dormancy progression

Authors: Dogramaci, Munevver; BILL, MALICK - North Dakota State University; FORTINI, EVANDRO - North Dakota State University; SARKAR, DIPAYAN - Orise Fellow; Kandel, Shyam

Submitted to: Postharvest Biology and Technology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/30/2025
Publication Date: 7/8/2025
Citation: Dogramaci, M., Bill, M., Fortini, E., Sarkar, D., Kandel, S.L. 2025. Postharvest storage conditions impact potato tuber microbiome and dormancy progression. Postharvest Biology and Technology. 230. Article 113766. https://doi.org/10.1016/j.postharvbio.2025.113766.
DOI: https://doi.org/10.1016/j.postharvbio.2025.113766

Interpretive Summary: Potato tubers are generally stored with a minimal cleaning after harvest, carrying a layer of microorganisms from field to storage. Microorganisms that remained in the skin or tuber flesh during storage can have beneficial as well as harmful effects on tuber qualities. Storage environments may be further influencing the abundance and diversity of these microorganisms in potato tubers and subsequently impacting their storage qualities. However, there is a significant knowledge gap in how different storage temperature and duration impact tuber microbiome. In this research, potato tubers were stored under two different storage temperatures over six months and tuber sprouting behaviors were monitored, and tuber tissues were collected for microbial and sugar analysis. Results of this study clearly indicate that storage temperature and duration alter profile of bacterial and fungal species in different tuber tissues and impact tuber sprouting. Key bacterial species with potential beneficial role in potato disease prevention and improving storage qualities were identified. Additionally, the storage conditions that favors harmful fungal species of potatoes were also determined. Insights from this study will help potato growers and industry to develop postharvest strategies for disease management and improving storage qualities of potato tubers.

Technical Abstract: Potato tubers are stored with minimal cleaning after harvest, carrying a layer of microbiome in tuber tissues from field to storage. The impact of postharvest storage on potato tuber microbiome is mostly unexplored. This study reports the effects of variable storage temperatures and durations on the potato tuber microbiome and how it influences tuber dormancy and sprouting. After harvest, potato tubers (cv. Russet Burbank) were either stored at 8°C, 21°C, or transferred from 8°C to 21°C 3 days prior to sampling of tuber tissues (primary bud, secondary bud, and tuber flesh) at 8, 12, and 17 weeks of postharvest storage. Sprout growth of the tubers was monitored weekly and different tuber tissues were analyzed for sugar content and the microbiome profile using rDNA (16S for bacteria and ITS for fungi) sequencing. Cold storage at 8°C suppressed tuber sprout growth and resulted in lower reducing sugar content in bud tissues when compared with tubers stored at 21°C. Overall, bud tissues exhibited significantly higher fungal and bacterial diversities compared with the tuber flesh. Storage temperature and duration significantly influenced bacterial and fungal communities and core bacterial species identified in tuber tissues have known beneficial roles in potato, while major fungal species identified in tuber tissues seem to be potentially pathogenic. Identified bacterial species such as Flavobacterium frigidarium and Bacillus coahuilensis can further be explored as potential sprout growth modulator, while Bacillus megaterium, and Arthrobacter sp. can be utilized for potato disease management during postharvest storage.