The Analysis On Pathogens And Physical Control Measure Of Main Diseases On Dried Jujube In Xinjiang

In the process of drying storage and transportation, jujube fruit easily get Mildew disease caused by Mildew. Along with some other diseases which are caused in the later stage of groeth, Mildew diseases is highly likely to mix into the dried fruit and spread during the period of storage. This ultimately may damage the quality of the fruits and reduce their market value. Clarify disease species,pathogen species, advantaged species and explore physical control method of dried jujube are significantly important to control occurrence and damage of this diseases.1. A samples of jujube fruit disease were collected from main jujube species area in xinjiang. Jujube fruit samples identification results show that, the main diseases of dried jujube diseases are five. They were jujube soft rot, jujube black spot, jujube fruit mildew, Jujube fruit shrink disease(bacterial diseases), Jujube fruit cracking(physiological diseases). Tissue isolation and moisture induced separation were used in isolation and identification for 3 species of fungal diseases, the result show that, they are belonging to 6 genera consisting of 18 species. Among Aspergillus was species of the highest isolate rate; Alternaria and Penicillium toke the second and third place. 15 species different morphological pathogens was screened out after using tie-back method on the fresh jujube fruit and dried jujube. Among 1 kind of Alternaria were isolated from jujube black spot; 1 kind of Rhizopus were isolated from jujube soft rot; And 5 kind of Aspergillus, 5 kind of Penicillium, 1 kind of Trichothecium, 1 kind of Fusarium and 1 kind of Rhizopus were isolated from jujube fruit mildew respectively.2. The morphological identification and 18 S rDNA-ITS sequence analysis showed that,the pathogen of jujube black spot was A. alternate. The pathogen of jujube soft rot was R. oryzae. The pathogen of jujube fruit mildew was A. niger, A. flatus, A. ruber, A. ochraceus, A. sydowii, P. polonicum, P. variabile, P. chrysogenum, P. minioluteum, P. brevicompactum, T. roseum, F. equiseti and R. oryzae.3. The isolated rate and pathogenicity analysis of fresh jujube fruit and dried jujube results showed that, Aspergillus was with a higher rate of isolating and a stronger pathogenicity. And R. oryzae was with a low rate of isolating and a stronger pathogenicity, but it have strong pathogenisity to fresh jujube fruit and dried jujube. The two pathogen species were advantage pathogenic species of dried jujube. The results on the biological character of pathogens reveals that, there are some difference in the temperature adaptability of 14 species of pathogen, and the optimum temperature was 25? and 30?. A. niger, A. flavus and R. oryzae can grow between 10?~40?. The lethal temperature of T. roseum, A. alternate and F. equiseti was 50?. The lethal temperature of P. polonicum, P. brevicompactum, P. variabile, P. chrysogenum, P. minioluteum, A. ruber, A. ochraceus and R. oryzae was 74?. A. niger, A. flavus and A. sydowii was 78?. The most suitable p H value was 7. The effect of light on mycelial growth was not evident.4. Result of physical control analysis of jujube storage disease showed that, the high temperature oven-drying method could evidently inhibit to Jun-jujube fruit mildew, Jun-jujube soft fot, Hui-jujube soft rot and Hui-jujube fruit shrink diseases. The 40?-40 h and 45?-35 h treatment method have inhibition effect for Jun-jujube mildew, the disease did not grow, and the control rate was 100%. The 45?-35 h treatment method have inhibition effect for Jun-jujube soft rot, and the control rate was 78.7%. The 45?-20 h treatment method have inhibition effect for Hui-jujube soft rot and Hui-jujube fruit shrink disease, and the control rate was 60%. The UV treatment method could evidently inhibit to Jun-jujube fruit mildew, Jun-jujube soft fot and Hui-jujube fruit shrink diseases. The 3 h UV treatment method have inhibition effect for Jun-jujube mildew, Jun-jujube soft fot and Hui-jujube fruit shrink diseases, and the control rate were 100%, 67%, 93.6% respectively. In addition, the UV treatment method have the strongest control effect for Jun-jujube fruit mildew, and the 1 h, 2 h, 3 h UV treatment method control rate were 100%.