The antifungal activity of chitosan on Fusarium sulphureum in relation to the inhibitory effect on dry rot of potato tuber was investigated. The results showed spore germination and mycelial growth of F. sulphureum we...The antifungal activity of chitosan on Fusarium sulphureum in relation to the inhibitory effect on dry rot of potato tuber was investigated. The results showed spore germination and mycelial growth of F. sulphureum were inhibited by chitosan treatment and the inhibitory effect was highly correlated with chitosan concentration used in this study. Morphological changes such as intertwisting hyphal, distortion, and swelling with excessive branching were observed by scanning electron microscopy （SEM） observation. Transmission electron microscopy （TEM） observation further indicated the ultrastructural alterations of hyphae. These changes included abnormal distribution of cytoplasma, non-membraneous inclusion bodies assembling in cytoplasm, considerable thickening of the hyphal cellular walls, and very frequent septation with malformed septa. Application of chitosan at higher concentration caused serious damage to fungal hyphae, including cellular membrane disorganisation, cell wall disruption, and breaking of inner cytoplast. New hyphae （daughter hyphae） inside the collapsed hyphal cells was often detected in the cytoplasm of chitosan-treated hyphae. In vivo tests showed that chitosan treatment at 0.5 or 1% effectively controlled the dry rot of potato tuber inoculated with a spore suspension ofF. sulphureum. However, the chitosan treatment at 1% caused phytotoxicity to potato tuber. This study suggests that the use of chitosan could be a promising handling as a natural fungicide to partially substitute for the synthetic fungicides in potato tuber.展开更多
The inhibitory effect and its virulence of chlorine dioxide(ClO_(2))against dry rot of potato were investigated.Potatoes were treated by ClO_(2),then observed for indoor bioassay,scanning electron microscopy(SEM)and t...The inhibitory effect and its virulence of chlorine dioxide(ClO_(2))against dry rot of potato were investigated.Potatoes were treated by ClO_(2),then observed for indoor bioassay,scanning electron microscopy(SEM)and transmission electron microscopy(TEM)were used to observe the morphology and ultrastructure of hyphae,and evaluated the control efficiency of ClO_(2) on potato tuber(LK99)dry rot by F.sulphureum pre-treatment.The results showed that the pathogen of potato dry rot was sensitive to ClO_(2),the virulence of regression of y=5.05+7.308x,EC50 and EC90 were 0.3490 and 0.6261 respectively,the treatment of ClO_(2) could significantly inhibit the spore germination and mycelium growth of F.sulphureum,which was in a concentration-dependent manner,SEM and TEM observed that the morphology and ultrastructure of F.sulphureum hyphae were regularly damaged by ClO_(2),in vivo experiment further indicated that ClO_(2) could effectively control the dry rot of potato tubers with F.sulphureum,and ClO_(2) at the concentration of 0.75 ug/mL could significantly reduce the incidence of potato tuber dry rot and lesion expansion rate.The study showed that ClO_(2) could greatly against the pathogen of F.sulphureum,which could provide a scientific theoretical basis for the safe and efficient application of ClO_(2) in the prevention and control of potato diseases after harvest.展开更多
基金supported by the Gansu Agricultural Bio-Technology Foundation, China (GNSW-2005-08)the R&D Special Funds for Public Welfare Indus-try (Agriculture) of Ministry of Agriculture of China(NYHYZX 07-6)
文摘The antifungal activity of chitosan on Fusarium sulphureum in relation to the inhibitory effect on dry rot of potato tuber was investigated. The results showed spore germination and mycelial growth of F. sulphureum were inhibited by chitosan treatment and the inhibitory effect was highly correlated with chitosan concentration used in this study. Morphological changes such as intertwisting hyphal, distortion, and swelling with excessive branching were observed by scanning electron microscopy （SEM） observation. Transmission electron microscopy （TEM） observation further indicated the ultrastructural alterations of hyphae. These changes included abnormal distribution of cytoplasma, non-membraneous inclusion bodies assembling in cytoplasm, considerable thickening of the hyphal cellular walls, and very frequent septation with malformed septa. Application of chitosan at higher concentration caused serious damage to fungal hyphae, including cellular membrane disorganisation, cell wall disruption, and breaking of inner cytoplast. New hyphae （daughter hyphae） inside the collapsed hyphal cells was often detected in the cytoplasm of chitosan-treated hyphae. In vivo tests showed that chitosan treatment at 0.5 or 1% effectively controlled the dry rot of potato tuber inoculated with a spore suspension ofF. sulphureum. However, the chitosan treatment at 1% caused phytotoxicity to potato tuber. This study suggests that the use of chitosan could be a promising handling as a natural fungicide to partially substitute for the synthetic fungicides in potato tuber.
基金supported by the Youth Fund Project of Gansu Academy of Agricultural Sciences(No.2015GAAS23)Special Fund for China Agriculture Research System(Cars-10)+1 种基金Special Fund for Agro-scientific Research in the Public Interest(201003077)the National Natural Science Foundation of China(No.31760476).
文摘The inhibitory effect and its virulence of chlorine dioxide(ClO_(2))against dry rot of potato were investigated.Potatoes were treated by ClO_(2),then observed for indoor bioassay,scanning electron microscopy(SEM)and transmission electron microscopy(TEM)were used to observe the morphology and ultrastructure of hyphae,and evaluated the control efficiency of ClO_(2) on potato tuber(LK99)dry rot by F.sulphureum pre-treatment.The results showed that the pathogen of potato dry rot was sensitive to ClO_(2),the virulence of regression of y=5.05+7.308x,EC50 and EC90 were 0.3490 and 0.6261 respectively,the treatment of ClO_(2) could significantly inhibit the spore germination and mycelium growth of F.sulphureum,which was in a concentration-dependent manner,SEM and TEM observed that the morphology and ultrastructure of F.sulphureum hyphae were regularly damaged by ClO_(2),in vivo experiment further indicated that ClO_(2) could effectively control the dry rot of potato tubers with F.sulphureum,and ClO_(2) at the concentration of 0.75 ug/mL could significantly reduce the incidence of potato tuber dry rot and lesion expansion rate.The study showed that ClO_(2) could greatly against the pathogen of F.sulphureum,which could provide a scientific theoretical basis for the safe and efficient application of ClO_(2) in the prevention and control of potato diseases after harvest.
