The Diversity Analysis Of Endophytic Fungi In Gray Jujube Fruit And The Screening Of Bio-control Strains Against Fruit Shrink Diseases

Zizyphus jujube plants are originated in China and are particular economictree plants of our country. The fruits have great nutritional value and commodity value.More and more fruit farmers begin to plant jujube trees. With the increasing of jujubeplantation area, the diseases of jujube fruits are becoming more and more seriously at thesame time. The diseases of jujube fruits can make a serious threat to the interest of fruitfarmers and the economic development of our country. Thus it is important and necessary todo research on the endophytic fungi of jujube fruits and the screening of antagonistic strainsagainst jujube fruit shrink disease.In this paper we have analysised the diversity of endophytic fungi of Gray jujube fruitsin Xinzheng, one of the main ares of jujube plantation in china. In order to provide a basisfor developing and utilizing the endophytic fungi in jujube, the endophytes of healthy jujubefruit are isolated, identified, and preserved..At the same time, we set Fusicoccum aesculi astarget pathogen, and screen antagonistic microorganism against it from jujube, purslane,pepper and so on, aimed at providing biological control and pretection against jujube fruitshrink disease.1. The isolation and identification of endophytic fungi in Xinzheng gray jujube fruit.In September2012in Xinzheng, Henan province, we collected gray jujube fruit andwashed the surface with tap water. A total of78strins were isolated from the fruits. Thestrains were identified to9geneus,16species through morphological and molecularcharacteristics, including three species of Alternaria, four species of Fusarium, three speciesof Diaporthe, and one species of Phoma, Phylostica, Pseudocercospora, Cercospora,Colletotrichum, Bipolaris. There are37strains of Alternaria and21strains of Phoma,occupied47.43%and26.92%respectively of total isolated strains.2. Analysis the diversity of endophytic fungi with SSCPGenomic DNA were extracted from jujube fruit and were used to do PCR amplicationwith the primers ITS1and ITS4. The PCR product were used to analysis the diversity ofendophytic fungi with SSCP. The results showed three ectrophoretic stripes were obtainedand was not enough to reflect the diversity of endophytic fungi. 3. The potential pathogenicity of endophytic fungi of jujube fruit.In the experiment, six fungi obtained, including Alternaria Alternata, A.tenussinum,Fusarium oxysporum, F.proliferatum, Colletotrichum gleosporioides, Phoma glomerat,were reported as pathogens which can cause jujube fruit diseases. They are considered aspotential pathogens.4. The screening of bio-control srains against jujube fruit shrink disease.We collected endophytic bacteria from jujube, purslane, pepper, and saprophytes on thesurface of apricot, apple, banana, and bacteria isolated from soil and Trichoderma in our labto screen biocontrol strains against Fusicoccum aesculi. Four strains were screened withsignificant control efficacy against F.aesculi through plate and vitro ecperiment. The fourstrains were identified as Bacillus.amyloliquefaciens through morphological characteristics,physiology and biochemistry characteristics,16S rDNA sequence data, and16S rDNA-23SrDNA internal transcribed spacer data.