桃拟茎点霉的侵染过程及其致病影响因子研究OA北大核心CSTPCD

[Objectives]Peach shoot blight(PSB)greatly influenced the development of peach industry,Phomopsis amygdali which caused PSB was the most prevalent pathogens in peach orchard at south China.However,the infection process and pathogenic influencing factors remain unclear.Therefore,this study aimed to explore the infection process of P.amygdali and its pathogenic influencing factors.[Methods]In this work,conidial germination of P.amygdali and infection sites were observed through scanning electron microscopy(SEM).Different environmental conditions were used to explore pathogenic influencing factors of P.amgdali.Commercial fusicoccin was used to measured its virulence effect.[Results]The germination rate of α-conidia of P.amygdali was 66.4%at 3 hours post inoculation,97.6%at 9 h,then,single long germ tube produced at 24 h,septum formed at 30 h,and branching mycelium formed at 36 h.SEM observation showed that infective hyphae might mainly infect xylem and pith part of peach twigs,that destroyed the structure of xylem,and there were no infective hyphae at the phloem.Further,the study found that temperature and relative humidity(RH)were the main factors affecting the pathogenicity of P.amygdali.Among them,30℃and 98%RH were the best optimum temperature and relative humidity for the disease.Fusicoccin,one toxin produced by P.amygdali,was also one of pathogenic factors of P.amygdali.[Conclusions]In this work,the infection process of P.amygdali was investigated for the first time and the main environmental factors affecting its pathogenicity were temperature and RH.