Pathogen Identification Of Valsa Canker On Fragrant Pear Tree And The Relationship Between The Canker And Euzophera Pyriella

Pyrus sinkiangensis Yu was derived from Korla region in Xinjiang, an ancient native species and important component of Xinjiang forest fruit industry. In recent years. Valsa canker and Euzophera pyriella make great harm to the production and quality of fragrant pear, so the identification of pathogen and their damage characteristics research have great significance to their control. In this study, using the morphological and molecular sequence features of the pathogens of fragrant pear canker and two apple canker, In order to know the relationship of the canker and the pest, investigating their damage characteristics in the wild field. The main research conclusions as follows:1. According to the stroma morphology, cultural characters and rDNA-ITS features of fragrant pear canker pathogen, the pathogen was identified as Valsa ceratosperma sensu Kobayashi.2. After studied the colony morphology and pathogenicity of different isolates of pear canker pathogen, these isolates were divided into three groups, grey-green, produced spore easy, weak pathogenic taxa, yellow, produced spore easy, strong pathogenic taxa and gray-white, produced spore hard, pathogenic taxa. But the rDNA-ITS of three taxa have no differences.3. The damage characteristics of canker and pest on fragrant pear showed that they could promote each other when they happened at the same time, the canker could also happen alone. There was no strict dependency relationship.