Chitosan reduces dry rot caused by Fusarium sulphureum on potato tubers: fungistatic and induced-resistance effects
Y. Bi.
Journal of Plant Pathology Volume 90 (2, Supplement) August 2008, Book of Abstract, 9th International Congress of Plant Pathology, August 24-29, 2008 Torino,Italy,. 507 pages.
2008
บทคัดย่อ
Chitosan reduces dry rot caused by Fusarium sulphureum on potato tubers: fungistatic and induced-resistance effects
Dry rot, caused byFusariumspp. is reported as the most important postharvest disease of potato inChina.F. sulphureumis one of the principal pathogens. The ability of postharvest application of chitosan to control dry rot was studied on potato cv.Atlantic.The results showed that lesion diameter after inoculation withF. sulphureumwas significantly reduced in tubers and slices treated with 0.25% chitosan. In vitro tests showed that chitosan decreased mycelium growth, dry weight of mycelium and spore germination. Changes in hyphal morphology were observed such as intertwining, distortion and swelling; inflated mycelium became blasted, wizened and cupped. Alteration of hyphal structure included abnormal distribution of cytoplasm, non-membranous inclusion bodies assembling in cytoplasm, considerable thickening of hyphal cell walls and very frequent septation with malformed septa. New hyphae (daughter hyphae) inside the collapsed hyphal cells were often found in the cytoplasm. Protection by chitosan was also associated with activation of peroxidase (POD), polyphenoloxidase (PPO), phenylalanine ammonia-lyase (PAL), the accumulation of total phenolics and flavanoids, and the production of H2O2and O2-..This suggests chitosan has dual effects: fungistasis and induced resistance, and is promising as a potential natural compound to control dry rot on potato tubers.