| Lonsdalea canker of poplar is newly discovered disease which occurred on the domestic widely planted varieties of Populus×euramericana, both the bacterium Lonsdalea quercina and the fungus Fusarium solani isolated from the poplar induced the symptom on cultivar of Populus×euramericana when conducting inoculation in wild and in greenhouse, but more typical symptoms induced when inoculated with L. quercina. The role of F. solani playing in occurrence of Lonsdalea canker of poplar is unclear.In order to clarify the relationship between the two kinds of micro-organisms in the process of Lonsdalea canker of poplar, dual culture and inoculation experiment, real-time PCR and field investigations were conducted, and those resulting data were analyzed by using SPSS software. The results indicated that F. solani had not been isolated in the bark tissue of healthy poplar, in contrast,the fungus isolation rate was55.3%in lesion of Lonsdalea canker of poplar. Antagonistic relations did not exist between L. quercina and F. solani in dual culture. The pearson correlation coefficient of lesion formed by mixed inoculation with L. quercina and F. solani, and inoculation separately with the two, were0.9and0.8respectively; that the higher correlation coefficient of L. quercina for the disease occurrence suggested that L. quercina played the major pathogenic role. Real-time fluorescent quantitative PCR detection showed that the quantity of L. quercina more rapidly increased than that of F. solani within inoculated tissue of poplar. The field investigation indicated that F. solani usually appeared on lesion of Lonsdalea canker of poplar in late stage. In summary, F. solani with lower virulence usually appeared accompanying with L.quercina, played an aggravating role for occurrence of Lonsdalea canker of poplar. |
