Sampling and Detection Strategies for the Pine Pitch Canker (PPC) Disease Pathogen Fusarium circinatum in Europe

Abstract

Fusarium circinatum Nirenberg & O’Donnel is listed among the species recommended for regulation as quarantine pests in Europe. Over 60 Pinus species are susceptible to the pathogen and it also causes disease on Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco) and species in genera such as Picea and Larix. The European Food Safety Authority considers the probability of new introductions—via contaminated seeds, wood material, soil and growing substrates, natural means and human activities—into the EU very likely. Due to early detection, constant surveillance and control measures, F. circinatum outbreaks have officially been eradicated in Italy and France. However, the global spread of F. circinatum suggests that the pathogen will continue to be encountered in new environments in the future. Therefore, continuous surveillance of reproductive material, nurseries and plantations, prompt control measures and realistic contingency plans will be important in Europe and elsewhere to limit disease spread and the “bridgehead effect”, where new introductions of a tree pathogen become increasingly likely as new environments are invaded, must be considered. Therefore, survey programs already implemented to limit the spread in Europe and that could be helpful for other EU countries are summarized in this review. These surveys include not only countries where pitch canker is present, such as Portugal and Spain, but also several other EU countries where F. circinatum is not present. Sampling protocols for seeds, seedlings, twigs, branches, shoots, soil samples, spore traps and insects from different studies are collated and compiled in this review. Likewise, methodology for morphological and molecular identification is herein presented. These include conventional PCR with a target-specific region located in the intergenic spacer region, as well as several real-time PCR protocols, with different levels of specificity and sensitivity. Finally, the global situation and future perspectives are addressed.

Potential Interactions between Invasive Fusarium circinatum and Other Pine Pathogens in Europe

“…Eliminating the importation of infested soil and plant trays/containers is also of crucial importance in controlling the spread of PPC. A number of recent reviews have addressed the issues of best practice for sampling for PPC [279], the role of insects in the spread of PPC [43], and environmentally-friendly control methods for the disease [36].…”

Alien Invasive Pathogens and Pests Harming Trees, Forests, and Plantations: Pathways, Global Consequences and Management

“…With forest IAPPs the only control options are mechanical approaches (such as sanitation cutting) [137], biological control, and the use of semiochemicals (e.g., mass trapping) [10]. While eradication of alien forest insects has been effective in some cases [138], the eradication of forest pathogens has always been incredibly challenging, with most of the successful interventions taking place in controlled environments (greenhouses and tree nurseries) or in urban green spaces (e.g., parks, trees, and gardens) [139].…”

Forest Pathology and Entomology

“…With forest IAPPs the only control options are mechanical approaches (such as sanitation cutting) [137], biological control, and the use of semiochemicals (e.g., mass trapping) [10]. While eradication of alien forest insects has been effective in some cases [138], the eradication of forest pathogens has always been incredibly challenging, with most of the successful interventions taking place in controlled environments (greenhouses and tree nurseries) or in urban green spaces (e.g., parks, trees, and gardens) [139].…”