Screening and Application of Stains for Cucumber Leaves Infected by Cucumber Downy Mildew Pathogen
Cucumber downy mildew is a prevalent fungal disease in cucumber production with severe impacts.To rapidly and accurate-ly identify the downy mildew pathogen on cucumber leaves and enhance the precision and timeliness of disease diagnosis,this study compared the in-situ staining effects of five staining methods—Coomassie Brilliant Blue R-250,Coomassie Brilliant Blue G-250,Trypan Blue,Methyl Blue,and Lactophenol Cotton Blue—on different infection stages of the cucumber downy mildew pathogen.The results indicated that Coomassie Brilliant Blue G-250 completed staining within 20 minutes,did not readily stain cucumber tissue,and allowed easy removal of excess dye.It demonstrated greater stability in staining observations of cucumber downy mildew,provid-ing better visualization of morphological characteristics at various stages of the pathogen.In conclusion,this study established a stain-ing method for cucumber downy mildew pathogen in cucumber leaves that offers excellent staining effects and a simplified experimen-tal procedure.It provides a technical approach for observing the infection structures of cucumber downy mildew and theoretical sup-port for forecasting and early warning of the disease.