Korla Pear Tree Biological Characteristics of the Valsa Canker Growth Pathogen and Its Pathogenicity

【Objective】This project aims to study Korla Pear Tree Canker fungus morphology,culture characters and pathogenicity to determine the biological characteristics and pathogenicity,and provide valuable information for disease prevention and control strategies. 【Method】Disease samples were picked up for section observation; under different environmental conditions( medium,temperature,p H,carbon source,nitrogen source,light) they were cultured and observed; the bacteria were inoculated on poplar( Populus bolleana Lauche),narrow leaved oleaster( Elaeagnus angustifolia L.),poplar( Populus euphratica),willow( Salixmatsudana Koidz),walnut( J. regia L.),apple( M. pumila Mill.),red dates( Ziziphuszizyphus) of the branches and leaves for observation and calculation of the incidence rate and the rate of lesion expansion. 【Result】The conidia devices had multi chambers with a sausage shape; bacteria optimum growth temperature was 20- 30℃,the optimum p H was 7,growing the fast under full light condition. The results showed that: lesion expansioninoculated on walnut leaves was the fastest,most slowly on the willow; they can form spore producing body in apple and poplar branches and spit out the yellow or orange conidia angles. 【Conclusion】Morphology identification of pear stem rot shell was C. carphosperma Fr. Differences existed in growth rate,color surface morphology,colony shape and pigment secretion under different environmental conditions. The bacteria could make 7different host susceptible,but there are significant differences in lesion expansion and sporulation ability,etc.