Objective:In this experiment,ELISA measurement was developed to detect antibody agaist PCV-2.Methods:A Cap sequence encoding for antigen epitope was obtained by PCR from the genome of porcine circovirus type 2 and then cloned into prokaryotic expression plasmids pET-22b(+).The plasmid of pET-22b(+)-cap was successfully constructed and transformed into E.coli BL21(DE3).An ELISA for detection of PCV-2 was established by high expression of Cap protein after induced by IPTG.Results:The results of Western blot showed that the expressed protein was 30 kD and possessed immunological activity.Positive rate was 73.1% and negative rate was 26.9% respectively for 643 serum samples which were examined with the measurement by ELISA.Conclusion:The ELISA method is applicable in clinic.

The pollen grains of 24 cultivarieties of Primus mimic of Rosaceae, which were collected from Shanghai, Hangzhou and Changxing. were observed by light microscope and scanning electron microscope. The pollen morphology of P.mume was first described as polytypism which could be distinguish into two classes and five types. Not only the pollen grains with 3-colporate. which were the primary form, but also the pollen grains with 4-colporate existed in many cultivarieties of P- tnume. The constitute of pollen types and sterility rate in each cultivarieties were also analysed. The result provides scientific reference for pollen identification, breeding and palynology.