DETECTION, DISTRIBUTION AND GENETIC DIVERSITIES OF APPLE STEM PITTING VIRUS AND APPLE STEM GROOVING VIRUS IN THE CZECH REPUBLIC

Apple stem pitting virus (ASPV) and Apple stem grooving virus (ASGV) are well distributed pome fruit tree viruses in Czech orchards and occurs either as single or mixed infections. A reliable and easy to use One-step-(duplex)-RT-PCR tool has been developed for the routine detection of ASPV and ASGV. The virus detection again confirms by sequence data of the viruses derived from PCR amplicons of the 3-terminal part of genome ASPV and ASGV. The nucleotide sequence of 3’ter ASPV genome (‘nt’ position 8992−9220) of tested Czech isolates has shown highly variable (identity range 80−100%). However, deduced amino acid sequences of C-ter coat protein gene have shown that some of these isolates are closely related (identity 100%). The phylogenetic analysis also confirms these results. The analysis of nucleotide and deduced amino acid sequences of 3’ter ASGV genome (‘nt’ position 6060−6481), and phylogenetic analysis of tested isolates has shown high homology among the Czech isolates of ASGV. The sequence identity has ranged ‘nt’ >94−100% and ‘aa’ >96-100%.