The gold immunochromatography technique was developed for the rapid detection of Pseudomonas syringae pv.lachrymans.Colloidal gold was obtained by reducing the gold chloride with sodium citrate,and 25 nm particles of colloidal gold were selected and labeled to polyclonal antibody(CMb) of P.syringae pv.lachrymans.CMb labeled with nanocolloidal gold particles was coated on the gold conjugate pad using the immune double sandwich method.The secondary antibody(goat anti-rabbit IgG antibody,targeting at the CMb) was coated on the surface of nitrocellulose filter membrane(NC) as the control line(C line),while CMb was coated on the surface of NC as the test line(T line),and the test strip was assembled.The prepared strip had a sensitivity of 106 cfu/mL and high specific,which was no cross reaction with including Pseudomonas fluorescens biovar Ⅱ and the other twenty-six strains.The working time of the test strip was about 15 minutes,and the strip stability test indicated that the result was reliable at 37℃ within 15 days.The test strip was used to detect samples of cucumber disease leaves collected from field,the C line and T line were observed clearly,while buffer solution control was negative reaction.The test strip can be applied to detect early bacterial angular leaf spot disease in cucumber production and direct the disease control.
