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1.
Acacia hybrid (Acacia mangium × Acacia auriculiformis) clones are widely planted in Vietnam with a total of approximately 400,000 ha to meet the demand for pulpwood, sawn timber and wood chip exports. Silvicultural techniques such as pruning and thinning have been applied to improve productivity and sawlog quality of Acacia hybrid plantations. However, those techniques may also create opportunities for wood decay fungi to enter the Acacia hybrid stems through wounds and cause stem defects that reduce sawlog quality and the value of the plantation. The presence of fungal decay agents in Acacia hybrid trees was examined in two Vietnamese plantations. In July 2011, just prior to a second thinning, discoloured wood samples were taken from a three‐year‐old Acacia hybrid plantation at Phan Truong Hai for the isolation of fungi. In July 2012, approximately 18 months after pruning and thinning treatments, discoloured wood samples were taken from a three‐year‐old Acacia hybrid plantation at Nghia Trung for the isolation of fungi. DNA sequencing of the rDNA ITS identified the isolates. In May 2015, approximately 4 years after thinning and fertilizer treatments, discoloured and decayed wood samples were taken from the above (7‐year‐old) Acacia hybrid plantation at Phan Truong Hai for fungal identification. DNA was extracted directly from discoloured and decayed wood samples and fungal rDNA ITS amplicons sequenced on a Roche 454 sequencer. The results showed that silvicultural treatments did not affect the fungal communities associated with discoloured and decayed wood of Acacia hybrid plantation at Phan Truong Hai. A total of 135 fungal species or OTUs (operational taxonomic units) were identified, including 82 members of Ascomycota and 52 Basidiomycota.  相似文献   

2.
Eucalyptus spp. and their hybrids are frequently cloned and mass planted across farmland tracts and commercial plantations in northern India. It is a viable feeder species to the paper and pulp industries in this region. In 2018 and 2019, during field surveys conducted in northern India, a serious leaf blight disease was frequently observed in E. tereticornis plantations. Isolation from the blighted leaf samples consistently yielded fungal isolates having Calonectria‐like morphology. Morphological features coupled with sequence analysis of partial β‐tubulin (TUB2) and partial translation elongation factor‐alpha (TEF1) gene regions of two fungal isolates confirmed the species as Ca. cerciana. In detached leaf assays and glasshouse inoculation experiments, both isolates produced symptoms similar to those observed on the naturally infected leaves. Koch's postulates were fulfilled by re‐isolating Ca. cerciana from the inoculated leaves. This work is the first to confirm that Ca. cerciana is associated with a serious leaf blight disease of Eucalyptus in northern India and is an important addition to the taxonomy of Calonectria fungi in India.  相似文献   

3.
Arambarria (Hymenochaetales, Basidiomycota) is a monotypic genus recently described to accommodate specimens from the Patagonian forests of Argentina wrongly assigned in the past to Inocutis jamaicensis. On the basis of a wide sampling of strains and phylogenetic analysis inferred from combined sequences including the nuc rDNA ITS1‐5.8‐ITS2 region, 28S rDNA D1‐D2 domains and partial sequences of translation elongation factor 1‐a (tef1‐α), we demonstrate that this genus is associated with an important canker rot of eucalypt plantations in Uruguay, to wood rots of many native and exotic hosts, and to “hoja de malvón” and chlorotic leafroll of grapevines diseases in Central Chile, Central Argentina and Uruguay, formerly assigned to I. jamaicensis and/or Fomitiporella sp. The combined phylogenetic analysis showed the existence of three closely related clades that corresponded to (1) the Pampas of Uruguay and Argentina (“uruguay” clade), (2) the Monte, Chaco Serrano and Yungas forests of Argentina (“cognata” clade) and (3) the Patagonian Andes forests and Chilean Province (“destruens” clade). Lack of morphological differences between taxa from the three clades, their occurrence in both native and exotic hosts, previous results showing interfertility between isolates from Uruguay and Argentina, and the lack of full support in the concatenated ITS + 28S + tef1‐α analysis, prevents us to distinguish and describe three different taxa; the proper name of the taxon being Arambarria cognata comb. nov. A fourth, distinctly separated clade corresponded to South African strains isolated from vineyards representing an undescribed taxon associated with Esca grapevine disease in that country. Arambarria is shown to be unrelated to Inocutis, with which it was confused in the past and, so far, remains restricted to the Northern Hemisphere in America (Mexico, Jamaica and the USA).  相似文献   

4.
In addition to Hymenoscyphus fraxineus, two fungi identified as Diaporthe eres aff. and Fusarium sambucinum aff. were also isolated from necrotic bark lesions on declining one‐year‐old Fraxinus excelsior in a forest stand in Montenegro. To examine their involvement in ash decline, a pathogenicity test was performed using under bark inoculations on one‐year‐old Fraxinus excelsior. Hymenoscyphus fraxineus was included as comparison. All three fungal species proved highly pathogenic towards one‐year‐old seedlings although lesion sizes differed significantly between the different species. Hymenoscyphus fraxineus was most aggressive, followed by F. sambucinum aff., while D. eres aff. caused the smallest lesions. This study demonstrates for the first time the ability of isolates in the D. eres and F. sambucinum species complexes to cause decline on one‐year‐old common ash seedlings.  相似文献   

5.
Diplodia sapinea and Diplodia scrobiculata are opportunistic pathogens of Pinus species. Several studies about taxonomy, impact and epidemiology of these fungi have been conducted in previous years, which have provided useful information and have raised new issues. These diseases produce a considerable impact on plantations resulting in significant economic losses. The main aims of this study are to increase the knowledge of the potential of genetic exchange and the relative aggressiveness of these organisms that can persist in healthy tissues of asymptomatic trees. A collection of 250 isolates among which are 149 strains collected from Pinus radiata plantations in Basque Country (Spain) and 101 strains from different countries was included in this work. Mating type ratios were analysed and compared using the structure of the MAT locus (MAT1‐1‐1 and MAT1‐2‐1). Inoculations of Pinus radiata seedlings were performed in a biosafety greenhouse (P2) to confirm pathogenicity of isolates and compare their aggressiveness. The frequency of occurrence of both idiomorphs of D. sapinea in Basque Country isolates was close to 1:1, however, for collection of isolates of this fungus from around the world, the ratio was 1:2. Furthermore, the spatial distribution of the two mating types in the Basque Country was random. Despite no detection of a sexual state, these results could suggest sexual reproduction behaviour. The pathogenicity of all strains in the collection was confirmed. Although aggressiveness (in terms of lesion lengths resulting from inoculation) varied greatly, no statistically significant effects of MAT type or pathogen species were detected.  相似文献   

6.
Since the myrtle rust pathogen (Austropuccinia psidii) was first reported (as Puccinia psidii) in Brazil on guava (Psidium guajava) in 1884, it has been found infecting diverse myrtaceous species. Because A. psidii has recently spread rapidly worldwide with an extensive host range, genetic and genotypic diversities were evaluated within and among A. psidii populations in its putative native range and other areas of myrtle rust emergence in the Americas and Hawaii. Microsatellite markers revealed several unique multilocus genotypes (MLGs), which grouped isolates into nine distinct genetic clusters [C1–C9 comprising C1: from diverse hosts from Costa Rica, Jamaica, Mexico, Puerto Rico, and USA‐Hawaii, and USA‐California; C2: from eucalypts (Eucalyptus spp.) in Brazil/Uruguay and rose apple (Syzygium jambos) in Brazil; C3: from eucalypts in Brazil; C4: from diverse hosts in USA‐Florida; C5: from Java plum (Syzygium cumini) in Brazil; C6: from guava and Brazilian guava (Psidium guineense) in Brazil; C7: from pitanga (Eugenia uniflora) in Brazil; C8: from allspice (Pimenta dioica) in Jamaica and sweet flower (Myrrhinium atropurpureum) in Uruguay; C9: from jabuticaba (Myrciaria cauliflora) in Brazil]. The C1 cluster, which included a single MLG infecting diverse host in many geographic regions, and the closely related C4 cluster are considered as a “Pandemic biotype,” associated with myrtle rust emergence in Central America, the Caribbean, USA‐Florida, USA‐Hawaii, Australia, China‐Hainan, New Caledonia, Indonesia and Colombia. Based on 19 bioclimatic variables and documented occurrences of A. psidii contrasted with reduced sets of specific genetic clusters (subnetworks, considered as biotypes), maximum entropy bioclimatic modelling was used to predict geographic locations with suitable climate for A. psidii which are at risk from invasion. The genetic diversity of A. psidii throughout the Americas and Hawaii demonstrates the importance of recognizing biotypes when assessing the invasive threats posed by A. psidii around the globe.  相似文献   

7.
In 2008, a canker disease caused by the fungus Corinectria constricta was detected in southern Chile. The causal agent was previously identified as Neonectria fuckeliana (now Corinectria fuckeliana), which has been associated with stem cankers in Pinus radiata plantations in New Zealand since the 1990s. Many basic aspects of the life cycle of C. constricta remain unknown. The current study aimed to (a) document the periods during which C. constricta fruiting bodies are present in P. radiata plantations and associated factors; (b) determine the C. constricta life cycle in P. radiata plantations in southern Chile; and (c) evaluate, under in vitro conditions, the sporulation dynamics of ascospores. The first and second aims were carried out by evaluating affected plantations every 15 days, identifying asexual and sexual fungal structures, and recording the time periods when the structures were present. The third aim was achieved with in vitro tests in Petri dishes simulating humidity chambers. The life cycle was characterized by the presence of sporodochia from the Cylindrocarpon‐like (asexual form of C. constricta) morph during the autumn of 2012 (March–May). Subsequently, perithecia began to form on the sporodochia during April of 2012, taking approximately 3 months to mature (May–July), persisting for the rest of the year and providing inoculum to infect new trees. The development of perithecia in winter demonstrates that this is the most important period for dispersal and infection. In terms of sporulation dynamics, perithecia can release ascospores up to eight days following a wetting event; without this event, the spores are not released.  相似文献   

8.
Bark beetle‐vectored ophiostomatoid fungi, Leptographium terebrantis, is inoculated on the roots and lower stems of stressed Pinus species during the feeding activity of bark beetle. To determine the exact host response following inoculation, it is critical to challenge the host with a realistic amount of fungal inoculum. Thus, we designed a series of stepwise experiments using L. terebrantis colonized toothpicks which focused on the inoculum transfer from the toothpicks to excised Pinus taeda stem segments and living saplings, respectively, at different inoculum densities. The toothpicks served as a substrate for fungal growth and sporulation and the inoculation showed their utility in eliciting host's response to the pathogen. The inoculated fungus caused blue‐stain and sapwood occlusions in P. taeda stems and saplings, respectively. The volume of occluded, visually damaged sapwood increased by 1.96 cm3 per radial inoculation point on average. Fungal colonized toothpicks can be used as a suitable alternative to agar discs for studying bark beetles vectored fungi and their host interactions.  相似文献   

9.
Ophiostoma species were isolated from bark beetles and Abies mariesii, A. veitchii and A. homolepis attacked by the beetles in Nikko, Tochigi, central Honshu, Japan. One to two Ophiostoma species were frequently isolated from each species of bark beetle. Ophiostoma subalpinum was the most common associate of Cryphalus montanus. Ophiostoma sp. B as well as O. subalpinum was a common fungus associated with Polygraphus proximus. Ophiostoma europhioides was isolated from Dryocoetes hectographus and D. autographus as one of the common associates. Ophiostoma sp. J and Ophiostoma sp. S were frequently isolated from D. autographus and D. striatus, respectively. These fungi seem to have specific relationships with particular bark beetles. Ophiostoma sp. B, Ophiostoma sp. J and Ophiostoma sp. S have unique morphological characteristics and appear to be new species. Five trees of A. veitchii, approximately 43 years old, were inoculated with five Ophiostoma species to assess the relative virulence of the fungi. Ophiostoma subalpinum, Ophiostoma sp. B, and O. europhioides had relatively higher virulence than the other species studied.  相似文献   

10.
In Europe, fungal pathogens have reduced the overall productivity of sweet chestnut (Castanea sativa) stands and continue to threaten the economic viability of forestry operations. Chestnut Red Stain (CRS) in north‐eastern Spain, locally referred to as Roig, is capable of decreasing the market value of chestnut timber to the point of rendering chestnut coppices uneconomical. Despite its economic importance, the specific cause of this red discolouration is unknown. With the objective of verifying the presence of fungi within the symptomatic wood, and identifying the fungus or suite of fungi associated with the red stain, wood samples were collected and cultured from 37 stumps found in eight recently harvested stands in the Montseny and Montnegre‐Corredor Natural Parks. To separate the fungi associated with CRS from other species inhabiting the chestnut wood, the origin of each fungal culture was mapped in every stump. The fungi were isolated from cultures and identified by sequencing the ITS region. The results provide insight into the fungal community inhabiting chestnut wood and the potential cause of CRS; nine species were identified including two species known to cause decay in chestnut. One of them, Fistulina hepatica, appears to be a likely candidate for the causal agent of CRS. This is the first study reporting the fungi associated with CRS and opens the door to new epidemiological studies focused on F. hepatica.  相似文献   

11.
Ophiostomatoid fungi are known to be associated with various species of bark beetles. However, information about fungal associates of root‐feeding bark beetles in Europe is still fragmentary. For this reason, the fungal associates of Hylastes ater, H. opacus and Hylurgus ligniperda on Pinus sylvestris were isolated and identified. A total of 743 fungal isolates were collected and separated into 10 morphological groups. Analyses of ITS rDNA and partial β‐tubulin gene sequences confirmed that these groups represented distinct species. The 10 species included a total of 13 associations between fungi and bark beetles that had not been recorded previously. All of the bark beetles examined were frequently associated with ophiostomatoid fungi. The fungal diversity and relative abundance of species were very similar in the three species of root‐feeding bark beetles. The most commonly encountered associates of these beetles were Grosmannia radiaticola, Leptographium lundbergii, L. procerum and L. truncatum. Insect infestation data furthermore suggest that Hylastes spp. and Hg. ligniperda are also important vectors of the fungal pathogen Sphaeropsis sapinea.  相似文献   

12.
In February 2015, an unexpected windstorm downed five hectares of a European black pine Pinus nigra subsp. laricio forest formation located close to Vallombrosa, Florence (Central Italy). In the following spring, an extensive survey was conducted in the area. Felled trees, stumps and all the suitable plant material were screened for the presence of the pinewood nematode (PWN), Bursaphelenchus xylophilus, by sampling wood and bark. Bark beetles were then collected from the gallery systems on the inner side of bark samples and observed in the laboratory. The following bark beetles were morphologically identified: Ips sexdentatus, Orthotomicus erosus, O. laricis and Pityogenes bidentatusa. The dissection of Ips sexdentatus allowed the extraction of numerous nematodes that were morphologically and molecularly identified as Ektaphelenchoides pini. Conversely, only few nematode specimens were isolated from either pine bark or wood. These individuals could be only molecularly identified and belonged to an undescribed nematode taxon. Even though no PWN was recorded in the investigated sites, our survey allowed the detection of a new association between E. pini and I. sexdentatus on P. nigra.  相似文献   

13.
Wilt disease caused by Fusarium solani is a serious constraint to Dalbergia sissoo (shisham) plantations in northern India. In this study, the antagonistic potential of 40 bacterial isolates recovered from rhizophere soil of healthy shisham trees, and a well‐characterized Trichoderma species (Trichoderma virens) were tested for their possibility as biocontrol agents for F. solani. Two promising isolates (S1 and S15) were identified which inhibited pathogen growth, caused chitin degradation, produced siderophores and solubilized phosphate in vitro. Isolate S15 scored highest for hydrogen cyanide (HCN) production while isolate S1 was a non‐HCN producer. These two isolates were identified as Serratia marcescens (S1) and Pseudomonas azotoformans (S15) following sequence analysis of 16S rDNA. In dual culture assays, T. virens caused 80% inhibition of mycelial growth of the test fungus. The three selected antagonists when tested in planta in the glasshouse completely suppressed production of wilt symptoms on 12‐month‐old shisham plants. Further work is needed to ascertain the potential of these isolates to be used as biocontrol agents to manage shisham wilt under field conditions.  相似文献   

14.
Supply of clear, unstained logs from an export country is important economically as well as in reducing the biosecurity risk to an importing country such as Japan. Although conditions found within the holds of ships containing logs are thought to be ideal for rapid colonization of sapstain fungi, no research has been conducted. Research-focussed log export trials were designed to determine the extent of sapstain colonisation at specific points in the processing of logs from harvesting to arrival at the export destination. Two trials were established, in the austral summer and winter, in which mature Pinus radiata logs were harvested in New Zealand and shipped to export ports in Japan. Data loggers placed above and below deck of the ships recorded microclimatic conditions. Nine species of sapstain fungi were isolated from logs during the summer trial; the most common species isolated were Ophiostoma floccosum, Ophiostoma querci, and Ophiostoma setosum. In contrast, ten sapstain species were detected during the winter trial, with Sphaeropsis sapinea, O. querci, O. floccosum, and O. setosum most commonly isolated. This research was the first successful attempt at measuring visual sapstain development and isolating sapstain fungi from the time of harvesting to arrival at an export destination.  相似文献   

15.
The association between Pityogenes bidentatus and fungi was studied in young, managed Pinus sylvestris stands in Poland. Fungi were isolated from emerged adults and their galleries collected from four populations. In total, 2089 fungal isolates including 42 species, were obtained. Penicillium sp. 1 and Geosmithia sp. 1 were the most commonly isolated fungi from beetles (49% and 41% of beetles respectively). Geosmithia sp. 1 species was the dominant species in P. bidentatus galleries with a frequency of occurrence of 57.9%. Hormonema dematioides was the second most abundant fungus in gallery systems (17.1% of wood samples). Two of the isolated Geosmithia species were previously undescribed. Pityogenes bidentatus also vectored three ophiostomatoid species: Ophiostoma minus, O. piceae and Graphium sp. ‘W’. These species were occasionally isolated from beetles and their galleries, suggesting a non-specific relationship.  相似文献   

16.
The aim of this study was to determine and quantify the wood‐decay fungi found on logs of forest tree species (beech, oak, hornbeam, Scots pine and fir) stored in log depots located in six different provinces in the Western Black Sea Region of Turkey. Additionally, it was aimed to determine the natural durability of some important wood species against the most commonly detected wood‐decay fungi. Eighteen families, 31 genera and 45 species belonging to the division Basidiomycota were detected; Antrodia crassa was identified for the first time in Turkey. The abundance of Panus neostrigosus, Polyporus meridionalis, Trametes hirsuta, T. versicolor and Stereum hirsutumincreased significantly with the holding time of the logs (r = 0.99, 0.87, 0.53, 0.57 and 0.78, respectively, p < 0.05). The majority of the fungal species were detected on logs stored in depots for 4–6 years (66%). The percentage of fungal species found on the logs with a holding time of three years or less was 29%, whereas the percentage for those detected on logs stored for seven or more years was 31%. Among the wood species, the greatest number of fungal species (29) and highest amount of fungi (2,539) occurred on beech wood. Natural durability tests showed that T. versicolor caused the greatest loss of wood mass, with an average of 23%. Field studies and natural durability tests performed in the laboratory showed that beech wood lost the most mass among the timber species studied.  相似文献   

17.
The Botryosphaeriaceae is a diverse family of endophytes and fungal pathogens of mainly woody plants. We considered the host range and distribution of these fungi by sampling diseased ornamental and forest trees and shrubs in Serbia, Montenegro, Bosnia and Herzegovina, spanning a Mediterranean and a Continental climatic region. In total, ten Botryosphaeriaceae species were identified in the Western Balkans and with the exception of Sphaeropsis visci and Phaeobotryon cupressi, which occurred on one host, all the species had a broader host range. Phaeobotryon cupressi was found only in the Mediterranean region and S. visci, Dothiorella sp., Dothiorella sarmentorum and Diplodia seriata were present only in the Continental region. Pathogenicity tests were conducted on a variety of hosts from which the Botryosphaeriaceae species were isolated. These included leaves and/or stems of seedlings of 21 hosts, and cut leaves and/or branches of six hosts. Moreover, stems of seedlings of Chamaecyparis lawsoniana, Cedrus deodara, Picea omorika, Pinus patula and Eucalyptus grandis were inoculated as hosts from which some or all of the Botryosphaeriaceae species used for inoculation were not isolated. Inoculations showed that the majority of these fungi could also co‐infect hosts other than those from which they were isolated. The results suggest that most of the species have broad host ranges and can potentially cause disease on a broad range of tree species under certain conditions.  相似文献   

18.
This preliminary study identified the fungal endophytes of Sitka spruce (Picea sitchensis) in four Scottish plantations, analysed their recruitment possibilities and community structure across the sites, and identified the possible origins of the endophytes in this non‐native host. Although Sitka spruce is native to north‐western North America, it comprises a huge portion of Scottish forestry and is an economically vital timber tree. Needles from two age classes were collected and cultured for emerging endophyte isolates. Using a combination of morphological features and genetic sequencing of the nuclear ribosomal ITS regions of representative morphological types, 57 morphotypes were recorded which represented at least 15 different species, including a hypothesized sister species to the pathogen of Pseudotsuga menziesii in North America and Europe, Nothophaeocryptopus gaeumannii (previously P. gaeumannii) that was present at all sites tested. Diversity, recruitment, site, needle age and needle part effects are discussed. The phylogeny of Nothophaeocryptopus based on analysis of combined ITS and Tub2 sequence data is given in order to assess the relationship of the unknown endophyte to the Douglas fir pathogen N. gaeumannii.  相似文献   

19.
We describe a holistic in vitro technique for inoculating roots of Prunus species with Armillaria solidipes, which is faster and more successful than previous methods. This method allows associated active and passive host defences to be assessed. Sterile root segments of three Prunus spp. were placed next to or on top of 14‐day‐old cultures of A. solidipes. At 21 day, the success of fungal penetration and length of the fungal colonization, and host responses were evaluated. Also, an anti‐Armillaria and anti‐Cladosporium activity detection assays were conducted by utilizing the root periderm, the first tissue that needs to be penetrated by fungus. These methods revealed the variation in the relative tolerance of three Prunus spp. to A. solidipes. The overall success of fungal colonization in the wounded and intact root, host defence, and antifungal activity significantly differed among three Prunus spp. Results indicate that this in vitro method can be used as a preliminary step in screening tree species to Armillaria spp.  相似文献   

20.
During the monitoring of the health status of nurseries and plantations in Serbia, a decline in a 5‐year‐old Paulownia tomentosa plantation was recorded. Trees displayed symptoms of dieback, massive breaking at different positions, the appearance of decay and fungal fruitbodies at the stems. Using standard isolation methods, white colonies with cottony surfaces and regular growth were obtained from the decaying wood samples, and after the oxidation degree analysis, it was determined that these isolates belonged to Davidson's group 6, indicating white rot basidiomycetes. To identify the isolated fungus, the ITS region of one selected isolate was sequenced. Based on the morphological analysis of the obtained colonies, collected fruitbodies and ITS sequence analysis, this fungus was identified as Trametes hirsuta. This is the first report of T. hirsuta on Paulownia tomentosa in Serbia. Irregularly performed pruning as the possible infection route and the implications of these findings are discussed.  相似文献   

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