Seaweed-derived polysaccharides improve post-harvest quality and longevity of strawberry fruits

  • Oral Presentation
  • Forestry and Horticulture
  • 12 Jun 2018 14:20
  • FS-G01, UCD Agriculture and food science Centre
  • View all IPSAM abstracts

E. Browne*
National University of Ireland, Galway
CyberColloids Ltd.

R. Campbell
CyberColloids Ltd.

S. Hotchkiss
CyberColloids Ltd.

Z. A. Popper
National University of Ireland, Galway

*Presenting Author

Strawberry soft rot, caused by the fungus Rhizopus stolonifer, results in significant post-harvest losses of strawberry fruits (Fragaria × ananassa) and associated economic losses. Growing concerns over the safety of conventional fungicides used to control R. stolonifer, coupled with the emergence of fungicide-resistant strains of the pathogen, have stimulated research into the development of environmentally-stable and potent alternatives as well as investigation into the effectiveness of different storage techniques. Naturally occurring seaweed-derived sugars (SDSs), both polysaccharides and oligosaccharides, are reported to have antifungal activity. The present study employed dip assays, radial-gel diffusion assays and liquid cultures, to examine the potential of SDSs to control R. stolonifer growth. Whole strawberry fruits, pre-treated by dipping in solutions of SDSs showed delayed fungal growth compared to a distilled water control. In vitro assays confirmed this inhibition of R. stolonifer growth. Radial-gel diffusion assays in which R. stolonifer was cultured on solid media treated with SDSs, and liquid cultures, in which the SDSs were added to Rhizopus cultures grown in media optimised for Rhizopus growth, confirmed that several SDSs are able to inhibit the growth of Rhizopus. Our results suggest that several SDSs have valuable potential application as an environmentally-stable alternative to commercial synthetic fungicides currently used in the treatment of Rhizopus rot.