Pathogen Identification Of Hamimelon Bacterial Fruit Blotch In Inner Mongolia And Methods For Detecting Fruit Blotch Bacterium In Hamimelon Seeds

Eight strains were isolated from diseased leaves of Hamimelon in Bayannaoer city Inner Mongolia. Inoculation test showed that these isolates are cause of the bacterial bruit blotch. All of the isolates were identified as Acidovorax avenae subsp. citrulli Willems, Goor, Iisieiemans, Gillis, Kersters & Ley by Gram staining, Casares-Gil, morphological characterization, colony pattern, physiological and biochemical reactions. Inoculations with these strains on leaves of cucumber, watermelon, pumpkin, calabash, bitter melon, tomato, eggplant, produced spot symptoms. Antiserum against the bacteria was prepared. The result showed that the bacteria in seeds can not be detected directly by slides Immunoagglatination, test tube immunoagglatination and agar double immunodiffuse assays. Combined immunoisolation and immunoidentification assays were developed for detecting the bacteria in Hamimelon seed. 102cfu/ml bacteria can be detected in seeds. In the experiment, the detection both on seed's carrying-bacterium part and on the carrying-bacterium rate of seeds was carried out. The result showed that carrying-bacterium part is its surface. Test for the correctness of these detecting result showed that inoculation on young Hamimelon with these isolates produced the same symptom as naturally infected plants and bacterium carrier rate of seeds was significantly positively correlated (α=0.05) both with the disease rate and with the disease exponent in field, which showed combined immunoisolation and immunoidentification assays was feasible .