The Isolation And Identification Of Kiwifruit Bacterial Canker In Sichuan And Research Of Its Crude Toxins

Kiwifruit bacterial canker is a kind of serious plant disease which mainly occurred in some kiwifruit-producing countries such as China, Japan, Ireland, Italy and so on. This pathogenic bacteria can spread distantly through kiwifruit plantlets, cion transplant materials and fruits’transportion and has already been put on a list of forest industry quarantine pests. This research based on the compare of symptom which occurred in different infected areas of Sichuan, the pathogenic bacteria were separated and identified, meanwhile, the crude toxins which can infect kiwifruit’s healty branches from this bacteria’s fermentation medium were extracted, finally, the impact of defended enzyme system was researched and analysed.The results were mainly as follows:1. The pathogenetic symptom of five different places in Sichuan were observed at the same time, it was found that the typical canker symptom placed in Mingshan and Cangxi represented rusty stain, purulence. While many patina tittles and russet cortical organization were infected infected plants which derived from Chongzhou, Deyang and Dujiangyan. Simultaneously, some white graininess thalli appeared on infected branches of Chongzhou.2. Some bacterica were separated from the kiwi ulcers branches of five different regions of Sichuan, the physiological and biochemical method were used, and the general primer was used to amplify16S rDNA clips of five different geographical origin of representative strains, then homologous recognition was carried by series BLAST.The results showed that compare the16S rDNA sequence of strains DY10, CZ8, MSI, CX9and DJY33with NCBI site on the PSA standard strains (GenBank AB001439.1), the homology was89.00%. Through phenotypic characterization and analysis of16S rDNA series analysis, the separation pathogen was identified as Pseudomonas syringae pv. actinidiae.3.The pathogen of kiwifruit bacterial canker could produced crude toxins which played a role of browning to kiwi callus in certain liquid medium.In order to get a optimal condition of culture, the culture conditions was optimized though comparing five kinds of liquid mediums, such as PGY culture medium, BP culture medium, GY medium, PDB medium and PD medium,PDB liquid medium was the best; At the same time, conclusion of DPS software analysis, the conclusion was that the best training time for poison was3d; The orthogonal test of variance analysis showed that production of bacteria toxins was largely affected by temperature, pH and oxyge, the optimum conditions:temperature,24℃, initial pH,5.5, bottled quantity,20mL. The optimized culture conditions greatly improved ability of approval strains to produce virose substances that the browning index could be up to90%.4. Three representative kiwi products such as JinKui (highly resistance), Haiwote(mid-resistance) and Qinmei (susceptible) in Sichuan, were seclected in this study. They were inoculated with pathogen crude toxin, and then SOD, POD, PPO, CAT, PAL physiological indexes were determinated, the results indicated that different varieties showed a obvious difference on the ability of the resistance to toxins, and the speed rate of SOD, POD, PPO of Jinkui after vaccinated toxins significantly higher than Haiwote and Qinmei in the whole process of the disease, while index fluctuation of the CAT and PPL of three varieties were not different significantly.