Evaluation of genetic resistance in Pinus to pitch canker in Spain

Pine pitch canker (PPC), caused by Fusarium circinatum, is considered among the most important diseases affecting pines in many locations throughout the world. In Europe, F. circinatum is currently present in the Iberian Peninsula, posing a high risk of its spread into currently disease-free countries in Europe. In the present study, the susceptibility of Pinus sylvestris, Picea abies, and Larix decidua originating in the Czech Republic to F. circinatum was tested. Furthermore, the presence of asymptomatic yet infected seedlings was also checked. This study demonstrated the pathogenicity of F. circinatum to the Czech provenance of P. sylvestris, whereas Picea abies and Larix decidua proved to be tolerant. The reisolation of F. circinatum beyond the inoculation point demonstrated that this quarantine pathogen is able to infect the three conifers tested, giving rise to asymptomatic seedlings for at least eight and a half months. To our knowledge, this is the first study in which the presence of symptomless seedlings has been recorded in the genera Picea and Larix. This finding points out that the European legislation would fail to avoid the risk of new introductions via symptomless seedlings, since this legislation is only restricted to plants of the genus Pinus and the species Pseudotsuga menziesii.

Section: Discussionsupporting

confidence: 92%

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

Martín‐García

Lukačevičová

Flores-Pacheco

et al. 2018

“…Iturritxa et al [24,60] demonstrated that two-year-old seedlings of P. sylvestris were relatively susceptible to F. circinatum. This fact, together with the Martínez-Álvarez et al [25] research, who found that damages in one-year-old inoculated and control seedlings were not different, seems to point out that P. sylvestris might acquire age-related resistance, in which a maturing plant or plant organ becomes less susceptible to pathogens [61].…”

Section: Discussionmentioning

confidence: 99%

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

Martín‐García

Paraschiv

Flores-Pacheco

et al. 2017

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.

“…Fusarium circinatum may be detected in any of the usual species found in these nurseries (P. pinaster, P. sylvestris, P. nigra and P. radiata) [5,17], although disease has only been recorded in plantations of P. radiata [18,19] and recently, in P. pinaster [19]. Disease outbreaks in nurseries are sporadic, which suggests an external source of inoculum.…”

Section: Introductionmentioning

confidence: 96%

“…The objectives of this work are to (1) determine the frequency of seeds with presence of F. circinatum collected from P. radiata trees, and evaluate the importance of seed contamination during its storage; (2) study persistence of the pathogen in seedlings, to demonstrate transmission of seed borne inoculum to the seedling; (3) study the effect of seed inoculum location and dose on infection and development of different host growth stages, including germination; and (4) perform a temporal analysis of the disease with different doses of inoculum. These evaluations will be performed under optimal conditions of temperature [21] on P. radiata, one of the most susceptible species [18,22], to determine the maximum disease infection rate.…”

Section: Introductionmentioning

confidence: 99%

Impact of Seed Transmission on the Infection and Development of Pitch Canker Disease in Pinus radiata

Evira-Recuenco

Iturritxa

Raposo

2015

Abstract:The aim of this study was to determine the impact of seed inoculum on subsequent disease development in nurseries, specifically studying incidence of seed infection, transmission rate of seed to seedlings, and rate of disease development from the primary inoculum source. Transmission rate of Fusarium circinatum (F. circinatum) from symptomatic trees of Pinus radiata (P. radiata) to seed was 0.73%, being the fungus mainly on the coat. Seed infection incidence was positively correlated with tree disease severity. Seeds also become contaminated with F. circinatum during storage, where high relative humidity had a great effect regardless of temperature. Transmission rates from seeds to symptomatic seedlings measured at 48 days after seed inoculation with 10 4 and 10 6 was 28% and 80%, respectively. Seedlings showed symptoms of wilting and dieback, and eventually died within the total duration of this study (475 days). By this time, there were two remaining symptomless seedlings (1% of the total). F. circinatum was recovered from each of them, demonstrating its persistence in seedlings. Fungus populations in roots were estimated between 10 5 and 10 7 cfu/g in symptomatic plants for both inoculum doses and up to 10 4 cfu/g in asymptomatic plants. Disease infection rate was similar in post-emergence damping-off (up two months growing) and for established seedlings (up to eight months) after seeds were inoculated with 10 4 spores/mL. OPEN ACCESSForests 2015, 6 3354