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Scots pine (Pinus sylvestris L.), a keystone species in Eurasian forests, supports diverse fungal communities and thus contributes to forest health and ecosystem functions. The southern marginal populations of P. sylvestris in Türkiye, situated in more arid and warm conditions, offer a unique environment to explore fungal biodiversity. In this study, the authors investigated the fungal assemblages in living (green) and dead (senescent, fallen, and litter) Scots pine needles in Türkiye. Using a culture-based approach coupled with DNA sequencing, distinct fungal communities were identified across different needle types. Frequent isolates included well-known P. sylvestris associates, including Lophodermium pinastri, Sydowia polyspora, and Cyclaneusma minus. Novel findings, such as unidentified Eurotiomycete and Basidiomycete taxa, suggest potentially new species and hidden fungal diversity in this biogeographically important region. Additionally, this study reports the first records of Desmazierella acicola and Phacidium lacerum in Türkiye, further underscoring the region's underexplored fungal biodiversity. Moreover, the biodiversity and community structure analysis revealed the intricate and complex nature of fungal colonization and succession, with significant variations between green, senescent, freshly fallen, and litter needles sampled concurrently. These findings provide new insights into the fungal communities of marginal, understudied Scots pine populations. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Brown spot needle blight, caused by Lecanosticta acicola, is a serious disease of pines worldwide and has become of great concern in Europe over the last decade, with significantly increased outbreaks in pine forests. We examined native and non‐native Pinaceae taxa (four Cedrus and 24 Pinus) in the Atatürk Arboretum, Istanbul, Turkey, for the presence of L. acicola. Needles were sampled from 37 trees at least twice between March 2017 and July 2018. Symptomatic occurrence of the disease was confirmed by isolations, followed by molecular identification via sequencing of the ITS region. Lecanosticta acicola was isolated from symptomatic needles of 10 trees from seven host taxa (Cedrus and six Pinus). Molecular diagnostics of isolates confirmed the identification of L. acicola on Cedrus libani, Pinus sylvestris, P. nigra subsp. nigra, P. nigra subsp. laricio, P. nigra subsp. pallasiana, P. nigra subsp. pallasiana var. fastigiata and P. nigra subsp. pallasiana var. pallasiana f. şeneriana in the arboretum. This paper is the first report of L. acicola on C. libani and also the first report of the pathogen infecting a genus other than a Pinus spp. under natural conditions. Additionally, it is also the first report of L. acicola occurring in Turkey. The pathogen was clearly able to cause severe damage on native Turkish Pinus taxa, including P. sylvestris and P. nigra subsp. pallasiana, and endangered endemic forms of the host in Turkey. [ABSTRACT FROM AUTHOR]

Dothistroma needle blight (DNB) is a serious disease of the Pinaceae, mainly Pinus species, caused by the fungi Dothistroma septosporum and D. pini. Both species are regarded as invasive forest pathogens worldwide, with rising incidence in central and northern Europe over the last three decades. In this work, 29 sites were investigated between 2013 and 2015 in south‐western Turkey. Morphological examination of needles confirmed DNB infection (i.e., Dothistroma conidiospores observed) at 18 sites, and a total of 108 Dothistroma sp. isolates were obtained from 11 of the sites. Host age seemed to be an important factor in both occurrence and severity of DNB in Pinus brutia forests. Continuous rainy days, especially in December, may increase severity of disease; however, extreme rain events may reduce available conidiospores on plant tissues or in the air. Species‐specific mating type primers showed that all isolates were D. septosporum; D. pini was not detected. The mating type ratio was close to 1:1, indicating sexual recombination was occurring. Eleven microsatellite markers revealed 59 unique multilocus haplotypes (MLHs) among the 73 isolates originating from different conidiomata. The majority of MLHs were represented by a single isolate (n = 52) and only one MLH was shared between two localities. Analyses showed high genetic diversity, isolation‐by‐distance, and clear population clusters. These findings suggest that D. septosporum is well established in south‐western Turkey and is probably not a recent introduction. [ABSTRACT FROM AUTHOR]

Pines are major components of native forests and plantations in Europe, where they have both economic significance and an important ecological role. Diseases of pines are mainly caused by fungal and oomycete pathogens, and can significantly reduce the survival, vigor, and yield of both individual trees and entire stands or plantations. Pine pitch canker (PPC), caused by Fusarium circinatum (Nirenberg and O’Donnell), is among the most devastating pine diseases in the world, and is an example of an emergent invasive disease in Europe. The effects of microbial interactions on plant health, as well as the possible roles plant microbiomes may have in disease expression, have been the focus of several recent studies. Here, we describe the possible effects of co-infection with pathogenic fungi and oomycetes with F. circinatum on the health of pine seedlings and mature plants, in an attempt to expand our understanding of the role that biotic interactions may play in the future of PPC disease in European nurseries and forests. The available information on pine pathogens that are able to co-occur with F. circinatum in Europe is here reviewed and interpreted to theoretically predict the effects of such co-occurrences on pine survival, growth, and yield. Beside the awareness that F. circinatum may co-occurr on pines with other pathogens, an additional outcome from this review is an updating of the literature, including the so-called grey literature, to document the geographical distribution of the relevant pathogens and to facilitate differential diagnoses, particularly in nurseries, where some of them may cause symptoms similar to those induced by F. circinatum. An early and accurate diagnosis of F. circinatum, a pathogen that has been recently introduced and that is currently regulated in Europe, is essential to prevent its introduction and spread in plantings and forests. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Diplodia shoot blight disease can cause significant damage on coniferous trees and be particularly injurious to cones, which reduces the amount of seed production and germination. We investigated the disease severity and genetic variation of Diplodia pinea in one Pinus nigra and two P. sylvestris seed orchards. Disease surveys were carried out in ?zmit (Marmara region, Turkey) in May 2012. Symptomatic shoots and cones were examined for the presence of pycnidia. Cultural and morphological characteristics of the isolates were studied using cultures grown on potato dextrose agar (PDA). Based on morphological characteristics and results using species specific primers, the pycnidia on shoots and cones were identified as D. pinea. In addition, Random Amplified Microsatellite Sequence (RAMS) analyses indicated that there was a single genet of D. pinea which caused the disease in the seed orchards. All of the 60 sampled trees were found to be infected by the fungus. There were differences in disease severity among the stands. [ABSTRACT FROM AUTHOR]

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Cylindrocladium buxicola is a fungal pathogen of Buxus spp. in Turkey; the pathogen was first noted in 2011 on the native populations of B. sempervirens in forests in Trabzon in the Black Sea region. Surveys conducted in November 2012 revealed a devastating impact of the pathogen on natural B. sempervirens populations, in which the trees were either dead or severely defoliated. The epidemic had spread 3-25 km along the river valleys near the Black Sea coast. Similar river valleys further inland were still free of infection or showed only the very first signs of arrival of the epidemic. The disease has recently been found also in nurseries. All isolates tested belonged to the G1 clade. [ABSTRACT FROM AUTHOR]

In 2017, severe symptoms of brown spot needle blight, similar to those caused by Lecanosticta acicola, were observed on needles of non‐native Pinus mugo var. Hesse planted in an arboretum in southern Sweden. Microscopic characterization and molecular diagnostics of isolates obtained from diseased needles confirmed the identity of L. acicola. This is the first report of the quarantine pathogen L. acicola in Sweden. Subsequent surveys are urgently needed to assess the presence and extent of the L. acicola invasion in Scots pine (Pinus sylvestris) stands in Sweden and other Scandinavian countries. [ABSTRACT FROM AUTHOR]

The import and export of tree seed carries with it risks of inadvertent introduction of pests and pathogens to hitherto unaffected regions. Although trade in seed of specified trees is regulated, phytosanitary requirements for most tree species are minimal, even those related to the most important forest tree species in a given region. A better understanding of the microbiome associated with seed intended for commercial production or ornamental use, and their potential risk with the transport from the source origin of distributors, will help regulatory agencies implement measures to safeguard seed health and avoid trade-related spread of potentially harmful pathogens. In this study we used high-throughput sequencing to show that highly diverse fungal communities were associated with seed of 14 different Pinus species obtained from seed banks (seed orchards) and retail sources (online distributors) in North America and Europe. Fungal diversity differed among the 23 seedlots tested. Community composition did not relate to the species of Pinus nor the country of origin. Assigned potential functions based on sequence identity using FUNGuild provided an overall understanding of the likely life strategies of fungal operational taxonomic units (OTUs). Of those sequences classified to a trophic level, 453 were plant pathogens, with the Dothideomycetes having the highest prevalence. The most common plant pathogens included Sydowia polyspora, Lasiodiplodia theobromae, Diplodia intermedia and Diplodia sapinea that were detected from the majority of Pinus species. The evidence presented here illustrates an urgent need for plant protection authorities, practitioners and the general public to recognize the potential risk of introducing harmful pathogens through innocent transport of seed. [ABSTRACT FROM AUTHOR]

Dothistroma needle blight, Lecanosticta brown spot needle blight and Lophodermium needle cast disease are among the most important pine diseases with ever increasing distribution areas and damages. Among the fungi that cause these diseases, Dothistroma septosporum, D. pini and Lecanosticta acicola are harmful organisms which are subject to quarantine. However, the situation of these fungi and the diseases they cause in our country is not exactly known. This study is aimed towards revealing the molecular methods as a fast and reliable approach in the detection of above mentioned major needle diseases. For this purpose, presence of the fungi which cause these diseases was investigated in Burdur red pine forests using a molecular method that utilizes species specific primers. Only D. septosporum and Lo. seditiosum were detected on the needles. Presence of these two fungi together is a great threat to productivity and maintainability of these forests. Furthermore, it was determined that their frequencies were varying between the sampling stands as well as the collection years. These results revealed that the molecular method used in this study is a fast and reliable method in detection of these fungi. More detailed studies should be done both in this forest and other pine forests in our country by using this method. [ABSTRACT FROM AUTHOR]

Dothistroma needle blight (DNB) is one of the most damaging foliage diseases of pine in plantations and natural forests worldwide and is caused by two closely related fungi: Dothistroma septosporum and D. pini, which are virtually impossible to differentiate from each other based on morphology. Although diagnosis of DNB based on symptoms is relatively reliable in the later stages of the disease when fruit bodies (conidiomata) are formed, for diagnosis in the early stages, as well as identification of the causal agent at species level, molecular methods are required. In addition, reliable and sensitive diagnostics before sporulation is a prerequisite for early detection to minimize accidental introductions of disease through movement of infected plant materials, especially seedlings. While amplification and sequencing of the ITS region of the rDNA alone is not reliable to differentiate the two species, conventional PCR (cPCR) using species-specific primers or mating type-specific primers and quantitative PCR (qPCR) are widely used and accepted molecular methods to identify and differentiate the DNB pathogens, either from cultures or directly from needles., (© 2022. The Author(s), under exclusive license to Springer Science+Business Media, LLC, part of Springer Nature.)

Dothistroma septosporum , the primary causal agent of Dothistroma needle blight, is one of the most significant foliar pathogens of pine worldwide. Its wide host and environmental ranges have led to its global success as a pathogen and severe economic damage to pine forests in many regions. This comprehensive global population study elucidated the historical migration pathways of the pathogen to reveal the Eurasian origin of the fungus. When over 3800 isolates were examined, three major population clusters were revealed: North America, Western Europe, and Eastern Europe, with distinct subclusters in the highly diverse Eastern European cluster. Modeling of historical scenarios using approximate Bayesian computation revealed the North American cluster was derived from an ancestral population in Eurasia. The Northeastern European subcluster was shown to be ancestral to all other European clusters and subclusters. The Turkish subcluster diverged first, followed by the Central European subcluster, then the Western European cluster, which has subsequently spread to much of the Southern Hemisphere. All clusters and subclusters contained both mating-types of the fungus, indicating the potential for sexual reproduction, although asexual reproduction remained the primary mode of reproduction. The study strongly suggests the native range of D. septosporum to be in Eastern Europe (i.e., the Baltic and Western Russia) and Western Asia.