Seed quantity affects the fungal community composition detected using metabarcoding

Pest introductions via trade in tree seed may result from a lack of adequate survey and validation protocols. Developing better diagnostic protocols to identify potentially harmful pests and pathogens in forest tree seed is of critical importance. High-throughput sequencing-based barcoding and metabarcoding provide effective tools for screening potentially harmful organisms in various plant materials, including seeds. However, the sample size needed to detect the total microorganism diversity of a community is a major challenge in microbiome studies. In this work, we examined how increasing sample size (ranging between 100 and 1000 seeds) influences diversity of fungal communities detected by high throughput sequencing in Pinus sylvestris seeds. Our results showed that as sample size increased, fungal alpha diversity also increased. Beta-diversity estimators detected significant differences between the mycobiota from different samples. However, taxonomic and functional diversity were not correlated with sample size. In addition, we found that increasing the number of PCR replicates resulted in a higher abundance of plant pathogens. We concluded that for the purpose of screening for potentially harmful pathogens using HTS, greater efforts should be made to increase the sample size and replicates when testing tree seed

Seed quantity affects the fungal community composition detected using metabarcoding

Acknowledgements We gratefully acknowledge COST Action FP 1406 “Pine pitch canker—strategies for management of Gibberella circinata in greenhouses and forests” (PINESTRENGTH), for supporting F.O. in this work. M.C. is supported by Te Swedish Research Council FORMAS (grant number 2018-00966). S.W. was part-funded by the UK Forestry Commission. Permission has been obtained for collection of seeds for the study.Peer reviewedPublisher PD

First report of Lecanosticta acicola on pine and non-pine hosts in Turkey

Acknowledgements We would like to thank İstanbul Bahçeköy Forestry Enterprise for allowing us to sample in the Arboretum, and to Merve Kartaloğlu Sönmez the manager of the Arboretum, for her hospitality. This study was partly supported by the Estonian Science Foundation grant PSG136, the Ministry of Rural Affairs of Estonia, and the Euphresco projects; Lecanosticta - Brown spot disease of pines – spread in European forest ecosystems: impact on pines, predisposing and contributing factors, control (BROWNSPOTRISK) and the International Plant Sentinel Network as an early warning system; research on future pest threats (IPSN II).Peer reviewedPostprin

Seydişehir İlçesi, Toros Göknarı meşcerelerinde Heterobasidion abietinum tarafından kaynaklanan çürüklüğün gövde içindeki gelişimi ve mücadelesi

Bu çalışmada, Seydişehir Orman İşletme Şefliği sınırları içinde yer alan karışık ve saf Toros göknarı meşcerelerinde bazı biyolojik etmenlerin ve kimyasalların, göknarlarda kök ve alt gövde çürüklüğüne neden olan Heterobasidion abietinum’ u engelleme üzerine etkileri ve bu ağaç türünde çürüklüğün gövde içindeki gelişimi araştırılmıştır. Arazi denemelerinde biyolojik mücadele etmenleri olarak, birer adet Trichoderma harzianum ve Phlebiopsis gigantea izolatı, kimyasallar olarak %30 üre (Tekkim) sulu solüsyonu ve boraks tozu kullanılmıştır. Çürüklüğün ağaç içindeki gelişiminin tespitine yönelik gerçekleştirilen çalışmada, biyolojik ve kimyasal muamelelerin yapıldığı alanlardan seçilen ağaçlardan, 1’er m aralıklarla diskler kestirilmiştir. Dip kütüğü seviyesinden başlayarak, her bir ağaçtan altı adet, toplamda 120 adet disk, laboratuvar koşullarında H. annosum s.l’a ait konidioforların varlığı açısından incelenmiştir. Toros göknarı meşcerelerinde H. abietinum’a karşı kimyasal ve biyolojik mücadele yöntemlerinin araştırıldığı bu denemelerde sırasıyla, üre, T. harzianum, boraks ve P. gigantea ile %98,90- 96,37- 96,25 ve 72,32 ortalama değerleri ile kontrole göre koruyuculuk sağlanmıştır. Bunun yanı sıra, patojen tarafından meydana getirilen çürüklüğün gövde içerisinde 5,5 m yüksekliğe kadar ulaştığı belirlenmiştir. Anahtar kelimeler: H. abietinum, Toros göknarı, Konya-Seydişehir, çürüklük, biyolojik mücadel

Cryptic Risks to Forest Biosecurity Associated with the Global Movement of Commercial Seed

Funding: This research was funded by the Swedish Research Council FORMAS grant number 2018-00966, and the UK Forestry Commission. Support was also provided by the EU-COST Action FP 1406 “Pine pitch canker - strategies for management of Gibberella circinata in greenhouses and forests” (PINESTRENGTH). Acknowledgments: We gratefully acknowledge laboratory support from Mohammed Elsafy, and the Forest Tree Seeds and Tree Breeding Research Directorate for providing the Turkish seeds. We gratefully acknowledge Dr. Alberto Santini from the Institute for Sustainable Plant Protection - C.N.R. in Italy for providing information on documented seed introductions to Europe from the international database he maintains.Peer reviewedPreprintPublisher PD

Spotting the pests of tomorrow—Sampling designs for detection of species associations with woody plants

Publication history: Accepted - 1 July 2019, Published - 4 August 2019.Aim Early warning against potentially harmful organisms of woody plant species can be achieved by sampling sentinel plants in exporting countries. However, it is unclear where sentinel plants can best be located, and how many samples are required and when and how often sampling optimally should take place for the adequate assessment of the biodiversity associated with the target plant species. We aimed to review spatial and temporal factors affecting associate biodiversity of single woody plant species and to develop guidance for the design of global biodiversity sampling studies. Location Worldwide. Taxon Insects and Fungi. Methods Literature about factors affecting the diversity of insects and fungi in association with single plant species on global, regional, local and different temporal scales was reviewed. Case studies of insect and fungal diversity, primarily collected on single plant species, and the cost of collecting and analysing samples from locations around the world were analysed. Results The review of the literature illustrated various factors affecting diversity, and the case studies allowed quantification of the relative impact of some spatial, temporal and financial aspects on captured biodiversity and, thus, illustrate the need to consider all possible factors that may affect the result of the sampling when deciding on a sampling design. Main conclusions Our study illustrates the factors that should be considered when deciding on the location and timing of sampling for sentinel plants, which is important because of the trade‐off between the number of samples and sampling locations needed to detect many of the species which may be potential pests, and the cost of (repeated) sampling in many locations. Decisions about the sampling design must be based on the objective of the sampling, but our recommendations apply irrespective of the targeted plant species or country.EuropeanCooperationinScienceandTechnology,Grant/AwardNumber:FP1401;SwissStateSecretariatforScience,EducationandResearchc,Grant/AwardNumber:C15.008

Diversity, migration routes, and worldwide population genetic structure of Lecanosticta acicola, the causal agent of brown spot needle blight

Lecanosticta acicola is a pine needle pathogen causing brown spot needle blight that results in premature needle shedding with considerable damage described in North America, Europe, and Asia. Microsatellite and mating type markers were used to study the population genetics, migration history, and reproduction mode of the pathogen, based on a collection of 650 isolates from 27 countries and 26 hosts across the range of L. acicola. The presence of L. acicola in Georgia was confirmed in this study. Migration analyses indicate there have been several introduction events from North America into Europe. However, some of the source populations still appear to remain unknown. The populations in Croatia and western Asia appear to originate from genetically similar populations in North America. Intercontinental movement of the pathogen was reflected in an identical haplotype occurring on two continents, in North America (Canada) and Europe (Germany). Several shared haplotypes between European populations further suggests more local pathogen movement between countries. Moreover, migration analyses indicate that the populations in northern Europe originate from more established populations in central Europe. Overall, the highest genetic diversity was observed in south-eastern USA. In Europe, the highest diversity was observed in France, where the presence of both known pathogen lineages was recorded. Less than half of the observed populations contained mating types in equal proportions. Although there is evidence of some sexual reproduction taking place, the pathogen spreads predominantly asexually and through anthropogenic activity

Global Geographic Distribution and Host Range of Fusarium circinatum, the Causal Agent of Pine Pitch Canker

Funding: This study was financially supported by COST Action FP1406 (PINESTRENGTH), the Estonian Science Foundation grant PSG136, the Forestry Commission, United Kingdom, the Phytophthora Research Centre Reg. No. CZ.02.1.01/0.0/0.0/15_003/0000453, a project co-financed by the European Regional Development Fund. ANSES is supported by a grant managed by the French National Research Agency (ANR) as part of the “Investissements d’Avenir” programme (ANR-11-LABX-0002-01, Laboratory of ExcellenceARBRE). SW was partly supported by BBSRC Grant reference BB/L012251/1 “Promoting resilience of UK tree species to novel pests & pathogens: ecological & evolutionary solutions (PROTREE)” jointly funded by BBSRC, Defra, ESRC, the Forestry Commission, NERC and the Scottish Government, under the Tree Health and Plant Biosecurity Initiative. Annual surveys in Switzerland were financially supported by the Swiss Federal Office for the Environment FOEN. Acknowledgments: Andrea Kunova and Cristina Pizzatti are acknowledged for the assistance in the sampling. Thanks are due to Dina Ribeiro and Helena Marques from ICNF-Portuguese Forest Authority for providing location coordinates. We thank three anonymous reviwers for valuable corrections and suggestions.Peer reviewedPublisher PD

Worldwide diversity of endophytic fungi and insects associated with dormant tree twigs

International trade in plants and climate change are two of the main factors causing damaging tree pests (i.e. fungi and insects) to spread into new areas. To mitigate these risks, a large-scale assessment of tree-associated fungi and insects is needed. We present records of endophytic fungi and insects in twigs of 17 angiosperm and gymnosperm genera, from 51 locations in 32 countries worldwide. Endophytic fungi were characterized by high-throughput sequencing of 352 samples from 145 tree species in 28 countries. Insects were reared from 227 samples of 109 tree species in 18 countries and sorted into taxonomic orders and feeding guilds. Herbivorous insects were grouped into morphospecies and were identified using molecular and morphological approaches. This dataset reveals the diversity of tree-associated taxa, as it contains 12,721 fungal Amplicon Sequence Variants and 208 herbivorous insect morphospecies, sampled across broad geographic and climatic gradients and for many tree species. This dataset will facilitate applied and fundamental studies on the distribution of fungal endophytes and insects in trees