Preharvest and postharvest application of Harpin was evaluated for its ability to induce resistance in muskmelon fruit and control rots. Preharvest treatments were 30 mg L^-1, 60 mg L^-1 Harpin or 1 mg L^-1 Imazalil e...Preharvest and postharvest application of Harpin was evaluated for its ability to induce resistance in muskmelon fruit and control rots. Preharvest treatments were 30 mg L^-1, 60 mg L^-1 Harpin or 1 mg L^-1 Imazalil either I week or I day before harvest. The CK was untreated. Fruit were then inoculated with Fusarium semitectum or Trichothecium roseum 48 h after harvest, and stored at 23± 1℃, RH （relative humidity） 50-60% for 4 d. All treatments were effective in reducing the lesion area with 60 mg L^-1 Harpin the most effectively. No treatments inhibited infection rate. Postharvest treatment was fruit dips of 30 mg L i, 60 mg L^-1 Harpin, 0.1 mg L i Imazalil. Fruit were inoculated with F. semitectum or T. roseum 24, 72, 120 or 168 h after treatment, and stored at 23 ± 1℃, RH 50-60% for 4 days. All treatments were effective in reducing the lesion area with 60 mg L^-1 Harpin the most effectively. No treatments inhibited the infection rate. Postharvest Harpin treatment induced the peroxidase activity increase, peroxidase activity reached maximum after 8 d and the activation lasted at least 10 d.展开更多
The wilt disease of Bambusa ventricosa was a serious disease occured in Nanping city, Fujian Province. The symptoms of the disease, identification, inoculation, biological characteristics of the causal organism and bi...The wilt disease of Bambusa ventricosa was a serious disease occured in Nanping city, Fujian Province. The symptoms of the disease, identification, inoculation, biological characteristics of the causal organism and bionomics of the wilt disease were studied. The species was identified as Nectria ditissima Tul. at sexual phase, and as Fusarium semitectum Berk. & Rav. at anamorphic state. The causal organism of wilt disease grew vigorously on the PSA and PSA+10% decoction of culm media, and formed white coloured colonies. After incubation of 7 days at 28℃, a great amount of macroconidia was produced, no stroma and perithecia were formed after 30 days. The stroma and ascospore were only produced under natural condition. The preference temperature for mycelia growth was between 25～28℃, and the optimum pH values was at 6～7. The optimum temperature for conidia and ascospores germination was between 25～28℃, and the optimum pH values was at 6～7. The high relative humidity (RH 96.1%～100%) was necessary for the germination of conidia and ascospores. The results of experiments showed that the pathogen of the wilt disease overwintered on the soil, and disseminated by winds and rains to infect the wounded stem base of Bambusa ventricosa. The primary infection occurred from the last ten days of February or the first days of March. The peak infection occurred from the first ten days of March to the second ten days of April during early summer rains. The infection ceased from the second ten days or the last ten days of May. The freeze injury was possibly important factor to induce infection of the wilt disease.展开更多
基金This study was supported by grants from Australia Center for International Agricultural Research(PHT/1998/140)M inistry of Science and Technology of China(2001BA501A09).
文摘Preharvest and postharvest application of Harpin was evaluated for its ability to induce resistance in muskmelon fruit and control rots. Preharvest treatments were 30 mg L^-1, 60 mg L^-1 Harpin or 1 mg L^-1 Imazalil either I week or I day before harvest. The CK was untreated. Fruit were then inoculated with Fusarium semitectum or Trichothecium roseum 48 h after harvest, and stored at 23± 1℃, RH （relative humidity） 50-60% for 4 d. All treatments were effective in reducing the lesion area with 60 mg L^-1 Harpin the most effectively. No treatments inhibited infection rate. Postharvest treatment was fruit dips of 30 mg L i, 60 mg L^-1 Harpin, 0.1 mg L i Imazalil. Fruit were inoculated with F. semitectum or T. roseum 24, 72, 120 or 168 h after treatment, and stored at 23 ± 1℃, RH 50-60% for 4 days. All treatments were effective in reducing the lesion area with 60 mg L^-1 Harpin the most effectively. No treatments inhibited the infection rate. Postharvest Harpin treatment induced the peroxidase activity increase, peroxidase activity reached maximum after 8 d and the activation lasted at least 10 d.
文摘The wilt disease of Bambusa ventricosa was a serious disease occured in Nanping city, Fujian Province. The symptoms of the disease, identification, inoculation, biological characteristics of the causal organism and bionomics of the wilt disease were studied. The species was identified as Nectria ditissima Tul. at sexual phase, and as Fusarium semitectum Berk. & Rav. at anamorphic state. The causal organism of wilt disease grew vigorously on the PSA and PSA+10% decoction of culm media, and formed white coloured colonies. After incubation of 7 days at 28℃, a great amount of macroconidia was produced, no stroma and perithecia were formed after 30 days. The stroma and ascospore were only produced under natural condition. The preference temperature for mycelia growth was between 25～28℃, and the optimum pH values was at 6～7. The optimum temperature for conidia and ascospores germination was between 25～28℃, and the optimum pH values was at 6～7. The high relative humidity (RH 96.1%～100%) was necessary for the germination of conidia and ascospores. The results of experiments showed that the pathogen of the wilt disease overwintered on the soil, and disseminated by winds and rains to infect the wounded stem base of Bambusa ventricosa. The primary infection occurred from the last ten days of February or the first days of March. The peak infection occurred from the first ten days of March to the second ten days of April during early summer rains. The infection ceased from the second ten days or the last ten days of May. The freeze injury was possibly important factor to induce infection of the wilt disease.
