Susceptibility of Several Northeastern Conifers to Fusarium circinatum and Strategies for Biocontrol

Abstract

Fusarium circinatum, the causal of pine pitch canker disease (PPC), is now considered among the most important pathogens of Pinaceae in the world. Although in Europe PPC is only established in the Iberian Peninsula, the potential endangered areas cover over 10 million hectares under the current host distribution and climatic conditions. It is therefore a priority to test the susceptibility of those species and their provenances, within Central and Northern Europe and find biological control agents (BCAs) against the disease. In this study, the susceptibility of Pinus sylvestris, P. mugo and Picea abies Romanian provenances to F. circinatum was tested using three inoculum doses. In parallel, the potential use of Trichoderma atroviride and Trichoderma viride as BCAs against F. circinatum was also tested. This study has demonstrated, for the first time, the susceptibility of P. mugo to F. circinatum. Likewise, the susceptibility of P. abies was also confirmed. The fact that the Romanian provenance of P. sylvestris has not been susceptible to F. circinatum suggests genetic resistance as a potential tool to manage the disease. This, together with the apparent effectiveness of Trichoderma species as BCAs, seems to indicate that an integrated management of the disease might be feasible.

Evaluation of the Susceptibility of Several Czech Conifer Provenances to Fusarium circinatum

“…Nevertheless, damping off caused by F. circinatum has been also reported in other conifers. Post-emergence damping-off, but not pre-emergence, has been reported in P. abies [28,50]. On the other hand, Martínez-Álvarez et al [28], in a field trial, did not find differences in the AUDPC values for 3-year-old P. abies seedlings between inoculated and control plots, which is consistent with the present study.…”

“…The present study used 1.5-year-old seedlings, whereas the seedlings used by Pérez-Sierra et al [61] and Mullett et al [63] were 7-8-month-old and one-year-old seedlings, respectively. So, this seems to point out that P. sylvestris might acquire age-related resistance, which had already been noted by Martín-García et al [50].…”

“…In fact, Martín-García et al [50] found that Romanian provenance of P. sylvestris was not susceptible to F. circinatum and this resistance was related to the high genetic variability of European Scots pine populations [67,68].…”

“…The Fusarium circinatum isolate (FcCa6) used in this work belongs to mating type 2 (MAT-2) and was isolated from an infected Pinus radiata tree located in Comillas (Cantabria, Northern Spain; GPS: 4 • 17 17.706" W; 43 • 20 5.033" N; 265 m above sea level) [28,[48][49][50]. Plant material consisted of seedlings of three Czech conifers: P. sylvestris, P. abies, and L. decidua.…”

Environmentally friendly methods for controlling pine pitch canker

“…Recently, Martín‐García et al . () reported the susceptibility of Picea abies seedlings, the main forest tree in central to northern and eastern Europe, to F. circinatum . Moreover, the inoculation of P. abies and Larix decidua seedlings from the Czech Republic with F. circinatum resulted in infected but symptomless plants, representing a new risk of introducing the pathogen from other species in the Pinaceae (Martín‐García et al ., ).…”