Identification And Research On The Chlorine Dioxide Efficacy Of Pathogens Causing Brown Spot Disease On Actinidia Chinensis

In recent years, with the Shaanxi Provincial kiwi cultivation area continues to expand, Kiwi occurrence of various diseases and hazards growing. In2011, the laboratory for the first time discovered a Kiwi brown spots disease in Zhouzhi County, Shaanxi Province. The incidence of serious regional, deciduos and fruit drop severely. Infected leaves from the edges of the leaves generally begin to dry up large tracts of dry leaves and litter. The disease throughout the growing season, fruit from young fruit start showing symptoms of the disease, a large number of serious diseases kiwifruit surface depressions, some fruit tissue cork, and affect the growth and development of fruit. To identify the pathogenic fungus of a serious disease which had caused brown spot disease to Actinidia chinensis, and screen out effective chemicals for inhibition of its mycelium growth. Study on bactericidal effect of chlorine dioxide on pathogens of kiwifruit. Provide the basis for effective disease prevention and control.The results were as follows:(1) Pathogen Identificationcollected from Brown Spot Disease on Actinidia chinensis three isolates. By pathogenicity tests, three strains can cause the onset of kiwifruit, fruit from the onset re-inoculation of the bacteria isolated, in line with the law Koch, prove that they are kiwi leaf spot pathogen.Fungal morphological characteristics of three purified pathogenic strains from different samples were the same, and then those strains were identified to the same pathogen. By pathogenicity test strains can cause the onset of kiwi, and from the fruits of re-vaccination onset isolated the bacteria. This result is in line with the koch postulates, thus proving that they are kiwi leaf spot pathogen. (2) Determination of the virulence of fungicides to A.alternata in laboratoryEighteen fungicides were used to determine the bacteriostasis effect on that pathogen, and the toxicity regression equation of them was also established. On10μg/mL drug-containing PDA plates, the average inhibition rate of the pathogen is more than80%by seven kinds of fungicides which are400g/L flusilazole,500g/L iprodione,80%tebuconazole,10%antimycin B,12.5%diniconazle,33.5%quinolinone and10%difenoconazole.400g/L flusilazole,500g/L iprodione,10%antimycin B and10%difenoconazole have a better inhibitory effect on Alternaria alternate than others used in this research.(3) Research on the efficacy of chlorine dioxide solution in killing Alternaria and PenicilliumInorder to know about the sterilization effect of chlorine dioxide solution with different concentration, reaction time, temperature and pH on Alternaria and Penicillium, we used suspension quantitative tests. The results show that:the5g/L sodium thiosulfate in0.02mol/L and PH5.9phosphate buffer solution can effectively neutrallize Alternaria and Penicilliums test concentration of chlorine dioxide, and the number of bacteria in each group were meet the requirements. Chlorine dioxide solutions effect on the mold spores is the combined result of many factors.100mg/L chlorine dioxide solution acted on Alternaria, Penicillium spores suspersion for5min have a better bacteridal effect, killing rate reached99.9%, sterilization effect is remarkable. In the test range, the bactericidal effect of chlorine dioxide solution increased with the raise of concentration, reaction time and temperature and with the drop of pH.(4) Research on the efficacy of chlorine dioxide gas in killing Alternaria and PenicilliumWith kiwi for the study, using chlorine dioxide gas as a bactericidal preservative. The sterilization effects of the concentration and action time of chlorine dioxide gas on Penicillium and Alternaria alternata (Fr.:Fr.) Keissler which were inoculated to wound of Kiwi and the influence of the wound infection rate were investigated. Chlorine dioxide gas to provide a basis for fresh kiwi and technology. The results showed that chlorine dioxide gas for Penicillium and Alternaria alternata (Fr.:Fr.) Keissler which were inoculated to wound of Kiwi with good sterilization effects. For the Wound infection condition of kiwi fruit has a certain inhibition. With the increase in the concentration and action time of chlorine dioxide gas, the Sterilization effect to improve. Larger role in which chlorine dioxide gas of concentration on the bactericidal effect.