DETECTION AND DISTRIBUTION OF FOUR POME FRUIT VIRUSES IN GERMPLASM COLLECTION IN THE CZECH REPUBLIC

A total of sixty-eight accessions covering native and foreign cultivars were collected and tested for the presence of the main pome fruit viruses: Apple stem pitting virus (ASPV), Apple stem grooving virus (ASGV), Apple chlorotic leaf spot virus (ACLSV) and Apple mosaic virus (ApMV). In two consecutive years (2005–2006), all samples were tested for the four viruses by pentaplex RT-PCR as well as by ELISA for the presence of ACLSV, ASGV and ApMV. Regardless of the cultivars or the origin, different combinations of mixed infections of viruses were identified in infected samples. All positive samples detected by ELISA were confirmed by pentaplex RT-PCR; however, RT-PCR revealed more infected trees than were discovered by ELISA. ACLSV and ASPV were the most prevailing viruses in apple and pear, the two viruses were detected in almost all mixed infections. Twenty-eight out of 29 apple accessions representing fifteen cultivars were mixed infected. The most prevailing viruses of apple were ACLSV (96,5%), ASPV (89,7%) and ASGV (34,5%); whereas there was only one apple tree infected with ApMV. The infection rate in pears was less; out of the 39 pear accessions 19 were infected. Neither ASGV nor ApMV were detected in tested pear samples. Only ASPV and ACLSV was detected in 17 and 5 accessions, respectively.