Evaluation Of Hte Predation Of Natural Enemies In Rice Ecosystem With Monoclonal Antibodies:development And Application Of Monoclonal Antibodies Against Rice Planthoppers And Collembola

Using the monoclonal antibodies developed respectively against rice planthoppers, brown planthopper, Nilaparvcua lugens (St釯), white-backed planthopper, Sogatella furc~fera (Horv醫h) and collembola, field predation of the major natural enemies of rice planthoppers and collembola were evaluated. The results were as follows: 1) Four monoclonal antibodies (McAbs), namely 3B2, 3B 11, 3H3 and 4B8, were developed against N. lugens using hybridoma technique. All McAbs had high absorption values even they were diluted over 4.096x 106 times. They reacted with all the stages of N. lugens while not cross-reacted with other insect pests and predators in the rice paddy. The 3H3 and 4B8 were the most specific. SDS-PAGE and Western blot analysis indicated that 3B2, 3B 11 bound specifically to one polypeptide with molecular weight of 287 kDa and 3113, 4B8 reacted with the polypeptides with molecular weights of 215, 199 and 167 kDa. At the temperature of 25 ~慍, the 3B2, 3B 11, 3H3 and 4B8 could detect the epitopes after one female of N. lugens had been ingested by Pardosa pseudoannulate for about 35.04h, 1l.45h, 8.81h and 45.91h, respectively. Immunodiffusion showed that all McAbs belong to IgG3 subclass. Based on the results as above, 4B8 was chosen to study the interactions between N. lugens and their predators in the field. 2) Five McAbs, namely 1B5, 2F10, 2Gl2, 3D8 and 4F8, were developed against the collembola using hybridoma technique. They had high absorption values even they were diluted over 1.024 X 108 times. All of the McAbs only reacted with the collembola while not cross-reacted with other insect pests and predators. Immunodiffusion showed that the 1 B5, 2F 10, 3D8 and 4F8 belong to IgG3 subclass, while the 2G12 belong to IgG?subclass. 3) Three variations of ELISA, direct, indirect and double antibody sandwich methods of ELISA were examined for their abilities to detect N. lugens antigens in the predator guts. The results showed that the direct and indirect ELISA were affected more strongly by the not-target antigens than on the double antibody sandwich ELISA. When the negative effects of the non-target were about 5%, the concentration of the non-target antigens was 0.042mg/mi with the direct and indirect ELISA methods and 0.214mg/mi with the double antibody sandwich ELISA methods respectively. The double antibody sandwich ELISA methods were the most sensitive when the 140 concentration of the non-target antigens was 0.214mg/mi. They could detect about 16.91 nglml (1/17509 individuals of the female/mi) of N. lugens antigens compared with 67.59ng/ml (1/4378 female/mI) for the indirect ELISA method and 135.l8ng/ml (1/2189 female/mi) for the direct method. The double antibody sandwich method of ELISA was established with the 4138 diluted 1000 times (28. 1 30 jig/mI), enzyme-linked antibody HRP-4B8 diluted 4000 times (1.045jig/ml) and sample diluted 100 times (1 OOml/individual) for detection of N. lugens antigens. The negative effect of the non-target antigens was lower than 5% and about 1.691 jig prey antigens (1/175 female) in a predator gut could be detected under this detecting system. 4) Indirect methods and double antibody sandwich methods of ELISA with 1 B5, 2F10, 2012, 3D8 and 4F8 were examined for their abilities to detect the collemboia antigens in predator guts. The results showed that the double antibody sandwich ELISA with 2012 was too insensitive to be...