PCR to differentiate hop pathotypes of Verticillium albo-atrum in Slovenia
Verticillium albo-atrum and V. dahliae (both on the EPPO A2 list) cause vascular wilt on many host plants and can cause economic damage on hop, more particularly V. albo-atrum. Verticillium wilt on hop presents different forms from mild to lethal, depending on pathogen virulence, cultivar susceptibility and ecological factors. In England, 3 types of lethal isolates of V. albo-atrum (PV1, PV2, PV3) have been reported and were distinguished on the basis of pathogenicity tests on different sets of hop cultivars. In Slovenia, hop wilt was first found in 1974 and appeared only sporadically in some hop gardens until 1997, when an outbreak of the lethal form of V. albo-atrum was reported in the western part of Savinja valley. In 2003, more than 180 ha of hop gardens had been affected. In Slovenia, on the basis of pathogenicity tests and molecular analysis, V. albo-atrum isolates have been classified as PG1 (mild) and PG2 (lethal) pathotypes. As pathogenicity tests are laborious and time-consuming, molecular tests were developed in Slovenia. Using specific primers targeting specific markers, it was possible to develop a PCR method which is able to differentiate rapidly between PG1 and PG2 pathotypes.
Sources
Radišek S, Jakše J, Javornik B (2004) Development of pathotype-specific SCAR markers for detection of Verticillium albo-atrum isolates from hop.
Plant Disease, 88(10), 1115-1122.