Selected achievements of Laboratory of Virology: Identification of Pear decline - MLO in declining pear trees in Poland. Development of RT-PCR method of detection of Apple stem pitting virus (ASPV) and Prunus necrotic ring spot virus Plum pox virus (PPV), Apple chlorotic leaf spot virus (ACLSV) and Prunus necrotic ring spot virus (PNRSV) and monoclonal (in co-operation with Institute of Biotechonology and Antibiotics , Warsaw) for. Plum pox virus (PPV) and Apple chlorotic leaf spot virus (ACLSV). Preparation and analysis of cDNA libraries containing fragments of several plant viruses. Reading the nucleotide sequence of CP gene for several plant viruses: ACLSV (1 isolate), PPV (2 isolates, 2 in preparation), PNRSV (8 isolates), ASPV (6 isolates). (PNRSV); application, evaluation and modification of RT-PCR based detection method of several other plant viruses. Preparation of antibodies: polyclonal for