Research On The Identification And Cross Infection Mechanism Of The Valsa Canker In The Oasis Ecological Jujube Orchard In Xinjiang

To verify the pathogen relating to valsa canker, and find out the relationship and differentiation relationship between these pathogen, in order to optimize IPM. Collection of samples and acquisition of pathogen by koche’s postulates. Then make research on biological characteristics of the pathogen existing under different condition and verify the classification by r DNA-ITS, EF-1α and β-tubulin. While make study on potential risk on Euphrates poplar rot pathogen infecting host. At last, find out the difference on pathogenicity of the pathogen from different host by cross infection. In addition, the research result below:1. The pathogen are classified into three groups, pathogen breeding fast in certain condition. All strains grow faster at 25℃-30℃,it was severely suppressed at 40℃.The best PH 4-6,lighting conditions has obviously promotion to each strain growth.In same stand structure, valsa canker pathogenicity form different host plants adaptability significantly to acid-base,some valsa canker pathogenicity still growth at PH 10 from Populus euphratica,willow and aspen, showed it have super adaptability to acid-base.And the pathogen from willow and aspen are better than from jujube at thermostability. valsa canker pathogenicity isolates have ex tensive needs to nutritiona.In different stand structure, valsa canker pathogenicity from same host plants have differences in cultural characteristics, valsa canker pathogenicity mycelial growth rate significantly different from jujube. Then the morphology of pathogen are different and complex relating to host and geographical location.2. Having found out that Cytospora chrysosperma resulted in valsa canker by analyzing phylogenetic tree of the gene of r DNA-ITS, β-tubulin and EF-1α. Then the relationship had nothing to do with geographical location and tree species composition was certain.3. From Willow,Poplar, Populus euphratica valsa canker strain virulence to each host stronger than strains from other strains.Among strains can infect each other and can produce spores,it showed Willow,Poplar, Populus euphratic and Jujube valsa canker pathogenicity may become each other infection source.From Jujube Cytospora chrysosperma have Strongest pathogenicity to Populus euphratic branches,the valsa canker strain from Willow showed high pathogenicity to jujube branches.Showed that our country forest valsa canker virulence is undergoing a process of differentiation relative strength. This article having found out that jujube is a new host for Cytospora chrysosperma.4. The study found that Populus euphratica valsa canker remaining morphological characteristics except for sporocarp size is basically consistent with jujube valsa canker, Populus euphratica valsa canker and jujube valsa canker genetic distance is less than 7.1%, consistency reached more than 99%.It showed the genetic relationship was very close between two valsa canker, previously not found jujube valsa canker in Xinjiang,so jujube valsa canker pathogen most likely derived from valsa canker on populus euphratica trees.