A total of 985 bacterial isolates were obtained from rice leaves and other grasses. The isolates were cultared in nutrient broth (NB) medium. After Centrifugated, 8000r/min for 10min, the supernatants of each bacterial NB cultures were tested for their suppressive effects on the germination and appressorium formation of Magnaporthe grisea. Of the tested isolates, 13 isolates showed suppressive effects. Three isolates identified as Psendomonas fluorescens (Xh216), Bacillus sp. (Xh222) and Pseudomonas. Sp. (Xh240), suppressed the disease severities on the detached rice leaves with the disease severity reduction 72.3%, 70.5% and 67.4%, respectively.

A mature appressorium cDNA library of rice blast fungus, Magnaporthe grisea, was constructed in a λ TriplEx2 vector by SMARTTM cDNA library containing 2.37×10.6 independent clones about 100% of which harbor foreign cDNA inserts with average size of 660bp. Of 9 randomly selected clones, 2 expressed tags (ESTs) sequences did not have homologous EST sequences of M. grisea in GenBank. The appressorium cDNA library is suitable for gene expression analysis and function analysis of the late stages of appressorium formation and the carly stages of penctration of M. grisea.

Eleven high effective monoclonal antibodies to Magnaporthe grisea were screened out from 230 hybrid cell strains showing positive reaction in ELISA tests, among which monoclonal antibody 2B4 showed more highly banding to cell wall surfaces of conidia, germ tubes, appressoria, germ tubes, appressoria or/and second infective hypha by indirect-immunofluorcscence test. Ultrastructural analysis and the antigen localisition of monocloual antibody 2B4 with immuno-gold labeling found this antigen protein exists extensively on cell wails of the diftbrrent life stages above, and is a secretion protein. 6 positive cDNAs, MP1, MP2, MP3, MP4, MP5 and MP6 were screened out with 2B4 from conidium cDNA expression library. A 31kDa protein expressed from a positive clone MP1 in a prokaryotic in vitro translation system was consistent with a 15kda protein from the extractive of the fungal surfaces, and its gene cloning and functional analysis are undertaking.