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1.
In managed spruce forests, Armillaria cepistipes and A. ostoyae are efficient stump colonizers and may compete for these resources when they co‐occur at the same site. The aim of this experiment was to quantify the mutual competitive ability of the two Armillaria species in producing rhizomorphs and in colonizing Norway spruce (Picea abies) stumps. Five isolates of A. cepistipes and two isolates of A. ostoyae were simultaneously inoculated pair‐wise into pots containing a 4‐year‐old spruce seedling. For comparison, each isolate was also inoculated alone. One year after inoculation, stumps were created by cutting down the seedlings. Six months after creation of the stumps, rhizomorph production and stump colonization were assessed. Armillaria spp. were identified from 347 rhizomorphs and 48 colonized stumps. Armillaria cepistipes dominated both as rhizomorphs in the soil and on the stumps. Nevertheless, A. ostoyae was relatively more frequent on the stumps than in the soil and A. cepistipes was relatively more frequent in the soil than on the stumps. In both species, the ability to colonize the stumps in simultaneous inoculations was significantly reduced compared with single inoculations. In respect to rhizomorph production, simultaneous co‐inoculations had a slightly stimulatory effect on A. cepistipes and no significant effect on A. ostoyae. Our study suggests a rather neutralistic co‐existence of A. cepistipes and A. ostoyae as rhizomorphs in the soil. Concerning the ability to colonize stumps, the two species experience a mutual negative effect from the interaction, probably because of interspecific competition. 相似文献
2.
The basidiomycetes Armillaria cepistipes and Armillaria ostoyae frequently occur in the same forest stand. In this study, we determined the virulence of 20 isolates of A. cepistipes and 16 isolates of A. ostoyae on four different provenances of 2‐year‐old Norway spruce (Picea abies). Within 30 months after inoculation, 1.1 and 19.1% of the seedlings inoculated with A. cepistipes and A. ostoyae, respectively, had died or were dying. The incidence of dead and dying seedlings varied between 3 and 49% among the A. ostoyae isolates. The virulence of an isolate was positively correlated to its ability to produce rhizomorphs. One Norway spruce provenance showed significantly lower susceptibility to A. ostoyae than the other three. Rhizomorphs of both Armillaria species were attached to the root surface. The attached rhizomorphs of A. ostoyae, however, were associated with significantly more lesions. The virulence of the isolates was not correlated with their wood‐degrading capability for either of the Armillaria species. 相似文献
3.
The occurence of Armillaria species was assessed in Norway, enabling the northern‐most distribution of this genus to be determined in Europe. Four Armillaria species were found in Norway. Armillaria borealis was the most common species occurring on woody vegetation to the permafrost zone (ca. 69°N). Armillaria cepistipes was present in southern and central Norway, but was not found further than 66°N. Armillaria solidipes and Armillaria gallica were rare, found at only one locality each; 59°40′ and 59°32′, respectively. Armillaria species were found on 14 hosts, but there was no significant difference between occurrence of A. borealis and A. cepistipes on declining and dead trees. Phylogenetic analyses separated each species into separate clades. All isolates of A. borealis, except one, and most isolates of A. solidipes were in separate clades. However, a subclade within the A. borealis clade was formed of two A. ostoyae and one A. borealis isolates. Two small A. cepistipes genets were found in a declining oak stand. 相似文献
4.
Symptoms and signs associated with root rot caused by Heterobasidion annosum or Armillaria ostoyae in mountain pines (Pinus mugo ssp. uncinata) were investigated in the Swiss Alps. A sample of dying or recently dead mountain pine trees (≥12 cm d.b.h.) and saplings (<1.3 m height) was assessed for root pathogen infection by taking root samples followed by isolations in the laboratory. From a subsample, an additional core was taken from the butt of each tree and evaluated in the same fashion. A total of 157 dying or recently dead mountain pine trees and 184 saplings with roots infected by either of the two pathogens or which lacked infection were analyzed using logistic regression models. The main objectives were to determine the most prominent symptoms induced by the fungi (resinosis), signs of the fungi (mycelia, fruiting bodies and rhizomorphs), and tree characteristics (d.b.h./height and evidence of wounds) that would allow an easy and reliable determination of H. annosum and/or A. ostoyae infection of mountain pines in the field. Heterobasidion annosum caused both root and butt rot on mountain pine, whereas A. ostoyae was mostly restricted to the root systems of the trees sampled. The most discriminating sign for the presence of A. ostoyae infection was the presence of characteristic mycelial fans, and for H. annosum root rot the presence of H. annosum mycelia (sheets of paper‐thin mycelium and mycelial pustules). In addition, resinosis was a powerful predictor for A. ostoyae in trees. Symptoms and signs indicating A. ostoyae or H. annosum infections were more reliable for saplings than for mature trees. Armillaria rhizomorphs were not useful in detecting A. ostoyae infection and, if present, were often formed by saprophytic Armillaria species. Heterobasidion annosum fruiting bodies were rarely observed and poorly reflected the widespread occurrence of this pathogen in the mountain pine forests. 相似文献
5.
Mycelial fan formation of three sympatric Armillaria species on excised stem segments of Picea abies 
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下载免费PDF全文 Mycelial fan formation was studied in five Armillaria cepistipes, ten A. borealis and ten diploid and six haploid A. ostoyae strains on excised stem segments of Picea abies. Stem segments were either non‐autoclaved or autoclaved, representing dying and dead wood, respectively. To confirm the identity of mycelial fans on non‐autoclaved stem segments, re‐isolations were made and isolates characterized with microsatellite markers. Mycelial fan formation on autoclaved stem segments was fast and reliable for most of the tested Armillaria strains. On non‐autoclaved stem segments, mycelial fan formation was slower, more erratic and less predictable. Mycelial fan formation was fastest in A. cepistipes closely followed by A. borealis and was slowest in A. ostoyae. For two A. cepistipes and four A. ostoyae strains (all diploid), growth rates of mycelial fans were estimated in a time course experiment. They ranged between 5.1 and 8.7 mm/day for autoclaved and between 1.4 and 4.7 mm/day for non‐autoclaved stem segments. The haploid A. ostoyae strains also formed mycelial fans on autoclaved stem segments, but typically slower and less reliably than the diploid strains. Whether haploid strains are able to produce mycelial fans on non‐autoclaved stem segments remains unknown because of accidental diploidization of the original haploid strains which was likely caused by basidiospores introduced into the study system on the non‐autoclaved stems. Overall, the method developed in this study may be useful for further investigations into the genetic, physiological and biochemical nature of mycelial fan formation in the genus Armillaria. 相似文献
6.
Parasitic association of the mycetophagous wood nematode,Bursaphelenchus fraudulentus with the honey fungus Armillaria ostoyae 下载免费PDF全文
下载免费PDF全文 M. Tomalak 《Forest Pathology》2017,47(3)
Honey fungi, Armillaria spp. are common and economically important pathogens of a wide range of tree species grown both in the forest and orchard cultures worldwide. Our field research in 73 forest stands across Poland has shown a common association of the mycetophagous wood nematode, Bursaphelenchus fraudulentus with Armillaria‐infected trees. The data reported here provide the first insight into the parasitic interaction of a nematode and Armillaria ostoyae. In laboratory conditions, B. fraudulentus reproduced on A. ostoyae, caused substantial damage to its mycelium and, finally, killed the whole colony within a short time. In ageing cultures, the nematode produced resting (dauer) juveniles. After artificial inoculation to Armillaria‐infected trees, the nematode population persisted under the bark, continued feeding and mass reproduction on the mycelium, and dispersed over the mycelial fans. The ability of B. fraudulentus to develop and reproduce on the surface and inside the fungal rhizomorphs suggests that these structures could facilitate the nematode dispersion in the environment. Since B. fraudulentus is not pathogenic to the host tree, its parasitic association with A. ostoyae may contribute to natural regulation of this fungus in the environment. The observed characteristics of this nematode suggest that it could potentially be used as a biocontrol agent of honey fungi in forest and orchard trees. 相似文献
7.
The distribution of Armillaria species was investigated in Serbian forest ecosystems, in relation to the main host species attacked, forest‐types, geography and altitude. In total, 388 isolates were identified from 36 host species in 47 sites. Armillaria gallica was the most commonly observed species with the widest distribution and with an altitudinal range of 70–1450 m, it was the dominating Armillaria species in lowland alluvial forests and in Quercus and Fagus forests at higher elevations. Armillaria mellea occurred in Quercus spp. – dominated forests in the north and central regions at 70–1050 m. Sixty‐eight per cent of the A. mellea isolates were collected from living hosts, most commonly in declining conifer plantations. Armillaria ostoyae was distributed in the cooler coniferous forest types and plantations in the Dinaric Alps in the south of Serbia, at 850–1820 m. Armillaria cepistipes was found in the eastern and southern hilly and mountainous regions of the country, at 600–1900 m. Most isolates were obtained from conifers and rhizomorphs in the soil around decaying stumps. Armillaria tabescens was found only on dead oak material in the northern and eastern regions of the country at altitudes lower than 600 m. 相似文献
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9.
The composition of the endophytic fungal assemblages in Quercus cerris, Q. pubescens and Q. robur, three oak species most susceptible to decline, was investigated in Fagarè (Padova), Ulignano (Pisa), and Radda in Chianti (Firenze). The endophytic assemblages were studied as a function of health status of the whole tree and of twigs and leaves. The effect of station altitude was tested on Q. cerris. Samples were gathered from healthy and declining trees. In April (bud opening time) 20 twigs and 10 leaves were collected from each tree. Fungi were isolated from twig segments and leaf portions. A total of 23 fungal genera with 27 different species were isolated, in addition to a few sterile mycelia. Eleven species were found to be common to all three oak species, while other species were found only on one oak species, suggesting host specificity. Among the fungal species isolated, some were known to be pathogenic (Apiognomonia quercina, Colpoma quercinum, Diplodia mutila, Phomopsis quercina). The colonization frequency (CF) of pathogenic species varied between 0.9% for A. quercina in Q. cerris and 60.2% for P. quercina in Q. robur. Analysis of variance showed a statistically significant difference among the oak species tested. The CF was higher in declining trees in comparison with healthy trees, and also in twigs vs. leaves. The CF was found to be higher for Q. cerris trees growing at sea level as compared with those situated at an elevation of 350–400 m. In stands where, on account of particular ecological conditions, pathogenic behaviour is displayed simultaneously by more than one endophytic fungal species, trees accentuate their decline. 相似文献
10.
The species composition of the endophytic mycobiota in bark, leaves and twigs of Laurus nobilis were studied in Western Anatolia. Four sampling sites were selected; one of which was sampled twice, in spring and autumn. About 3892 fungal isolates obtained grouped into 85 morphological types. The 11 dominant species, with isolation frequencies >1.5%, were Alternaria alternata, Botryosphaeria sarmentorum, Colletotrichum dematium, C. gloeosporioides, Hendersonula sp., Paraconiothyrium sp., Phoma sp., three species of Phomopsis and Seimatosporium lichenicola. Numbers of fungal species isolated per tree differed between the sampled sites. Isolation frequencies of the dominant species, and other less frequent species, were dependent on the sampling site. The degree of endophytic infection and the diversity of fungal species were significantly higher in spring. Frequencies of all dominant species depended significantly on season, except for Stemphylium sp. and S. lichenicola. Analysis of the total endophytic mycoflora of the sampled trees suggested that geographical factors affects the endophytic distribution patterns more significantly than seasonal factors. 相似文献
11.
Christ's thorn (Paliurus spina-christi Mill.) tree is an important and valuable forestry species and has significant potential in afforestation and reforestation systems. In recent years, dieback symptoms were observed on Paliurus spina-christi trees in Gilan-e Gharb region of Kermanshah province, west Iran. During 2020 to 2021, Christ's thorn trees that exhibit branch dieback symptoms were sampled for fungal isolations. The pathogenicity tests, biochemical assay of growth, acid production on creatine sucrose agar (CREA) medium and morphological and molecular investigations (ITS and β-tubulin regions) identified Paecilomyces formosus as a dieback causal agent. This is the first report of P. formosus pathogenicity on Paliurus spina-christi trees. Furthermore, disease severity was assayed on 11 tree species under three different temperatures 15, 25 and 35°C. Disease severity caused by all isolates on detached branches was greater at 35°C than at 15 and 25°C. This study presents the host range of this pathogen and showed that these potential hosts are prone to this pathogen under high temperatures, which forest trees experienced in recent decades. 相似文献
12.
R. Siepmann 《Forest Pathology》1985,15(2):71-80
Occurrence of species and clones of Armillaria in spruce stands, mixed stands and hardwood stands in close neighbourhood . From Armillarid rhizomorphs (collected around trees) and from spruce butt rots, isolates of the diploids were made. In pairings between the diploid isolates and haploid testers from the five (European) biological species (BULLER phenomenon) the mating reactions often were not clear enough to identify the diploids. So carpophores were raised from the isolates and single spore cultures were obtained. In pairings with the haploid testers Armillaria borealis, A. bulbosa and A. bulbosa were identified. Usually more than one Armillaria species and from each species more than one clone occurred in each stand. 相似文献
13.
Armillaria causes problems of root rot, kill trees and decay wood in the forests of Serbia and Montenegro, but the species involved have not hitherto been identified. The aim of this study was to identify field isolates collected on 25 localities. Identification was based on restriction fragment length polymorphism (RFLP) analysis of intergenic spacer 1 (IGS1) region and comparisons of IGS1 sequence with those available on NCBI database. Phylogenetic analysis was performed on sequence information from selected isolates to determine possible interrelationships between isolates with different banding patterns and previously identified tester isolates of five European Armillaria species. Five Armillaria species were identified in 90 isolates obtained from forests in Serbia and Montenegro. Armillaria gallica was most frequently isolated, followed by A. cepistipes, A. mellea, A. ostoyae and A. tabescens; two isolates remained unidentified. Restriction digestion of IGS1 amplification products with AluI produced 10 RFLP patterns. Patterns G4 (400, 250, 180) for A. gallica and pattern X (400, 180, 140) for isolates 74 and 79 are reported for the first time in European isolates. Eight RFLP patterns were observed after restriction with TaqI. Two patterns each were observed for A. ostoyae and A. gallica, and one each for A. cepistipes, A. mellea, A. tabescens and isolates 74 and 79. Parsimony analyses based on the IGS1 region placed the isolates into four clades: one including A. mellea, the second containing A. gallica–A. cepistipes isolates, while isolates of A. ostoyae and A. borealis were in the third clade. Armillaria tabescens differed from all annulate species. Phylogenetic analysis supported the conclusion that European Armillaria species are closely related and separated from a common ancestor in the near past. According to this survey five European Armillaria species are present in the forests of Serbia and Montenegro, while A. borealis is not present in the studied ecosystems. 相似文献
14.
Hakimeh Ziaie Juybari Mohammad Ali Tajick Ghanbary Heshmatollah Rahimian Kaivan Karimi Mahdi Arzanlou 《Forest Pathology》2019,49(6)
A total of 4,009 endophytic fungal isolates were recovered from healthy leaves, bark and xylem of Citrus sinensis in different seasons and age‐classes. Corresponding to those factors, the majorities of fungal isolates were recovered from leaves, 2‐yr‐old trees and winter, respectively. Fungal isolates were initially categorized based on cultural and morphological characters, and representatives of each morphotype were subjected to molecular identifications based on ITS‐rDNA and β‐tubulin sequences. All isolates obtained in this study belonged to the phyla Ascomycota and Basidiomycota assigned to 30 fungal taxa. The most abundant fungal species were Alternaria spp. Species diversity indices of Margalef richness and Shannon–Wiener revealed a high diversity of fungal taxa recovered from leaf and during winter. Frequency (%) of fungal endophytes was highest in winter followed by summer, autumn, and spring significantly, whereas the corresponding sequence was winter, autumn, summer and spring for the diversity of endophytic fungi. Overall, the results of this study based on the community and diversity of endophytic fungal species in C. sinensis showed that the type of plant tissue, season of sampling and age of tree play a driving role on their abundance while their diversity was mainly dependent on the type of plant tissue, season of sampling than on the age of tree. 相似文献
15.
Genotype distribution of Raffaelea quercivora in the oak galleries and its composition in the mycangia of Platypus quercivorus 下载免费PDF全文
下载免费PDF全文 Raffaelea quercivora is the pathogenic fungus that causes Japanese oak wilt. The female monogynous ambrosia beetle, Platypus quercivorus, carries this fungus in mycangia on the pronotum. These beetles bore galleries in oak trees with their partners to produce offspring, and they deposit fungus on the gallery walls from their mycangia. The offspring mature in the gallery, before loading the fungal pathogen and flying from the gallery to other healthy trees. To investigate the unloading and loading modes of the fungus within the gallery, we developed four polymorphic microsatellite markers for R. quercivora and identified the fungal genotypes in the galleries and mycangia of the beetles. Small wood chips were sampled at 5–10‐mm intervals from the walls of five galleries in a dead Quercus serrata tree. The pronota were also sampled from five female adult beetles. The genotypes of the R. quercivora isolates from the wood chips and pronota were identified using the microsatellite makers. The genotypic analysis showed that each gallery was inhabited patchily by 5–10 genotypes of R. quercivora, and the mycangia of each beetle contained 3–6 genotypes. These results indicate that diverse R. quercivora genotypes are unloaded repeatedly from the mycangia of female beetles onto the gallery wall, which results in their patchy distribution on the walls. When the offspring leave the host tree, the fungal clones that proliferate in the walls are also loaded repeatedly into the mycangia of the mature beetles. 相似文献
16.
[目的]研究柚木人工林生长过程及其与气象因子的相关性,为柚木抚育经营提供理论依据。[方法]以优良、中等和差3种生长类型的30余年生柚木人工林为对象,基于样地调查,选取优势木、平均木、被压木进行树干解析,对比分析其生长过程,应用灰色关联分析法揭示气象因子对柚木生长的影响。[结果]表明:3种生长类型林分柚木胸径、树高和材积生长过程基本一致,各分级木的生长过程亦相似,其胸径平均和连年生长量随年龄的增大呈先增加后逐渐降低的趋势,树高生长整体上呈下降趋势,材积生长则呈递增趋势。各优良林分的林木及各类型林分的优势木,其胸径、材积平均和连年生长量较大,速生期持续时间长,生长衰减慢,而其树高生长量的优势相对不明显;30余年生时柚木尚未达数量成熟龄。各类型林分间柚木生长与气象因子关系的差异仅体现在胸径,优良林分胸径连年生长量主要受极端低温影响,而中等和差林分则与年均降水量相关性最大;各分级木间柚木生长与气象因子的关系无明显差异;影响树高和材积连年生长量的最主要气象因子分别为年均降水量和年均气温。[结论]柚木各生长类型及分级木的生长过程整体趋势基本一致,其差异主要体现在生长量大小和快速生长期长短。约30年生柚木人工林仍未达到数量成熟,后期抚育经营对于其优质大径材高效培育仍不可忽视。 相似文献
17.
We investigated an Armillaria root disease centre in a 60‐year‐old, naturally regenerated Pinus sylvestris stand located at 1250 m altitude in Sinop province in northern Turkey. Based on sequence analysis of the internal transcribed spacer region of the rDNA, the mycelial fans sampled from the infected trees were Armillaria ostoyae. Multilocus genotyping indicated that the fans belonged to a single genet, at least 0.2 ha in size. Drought as a predisposing factor is discussed. The study area received 50–70 and 25–50% of the normal precipitation in May, June and August in 2009 and in August and September in 2010, respectively. Moreover, earlier excavation work to prepare a forest road had probably disrupted the water table in the affected stand. 相似文献
18.
Local epidemiology of the wood decay agent Laetiporus sulphureus in carob stands in Sicily 下载免费PDF全文
下载免费PDF全文 The basidiomycete Laetiporus sulphureus (Bull) Murrill is a forest pathogen causing brown cubical heart rot in a broad range of host trees. Despite its wide distribution and importance, studies aimed at understanding the epidemiology of the fungus in specific areas or hosts are lacking. In this study, an incidence of L. sulphureus as high as 34% was determined through molecular analysis of wood samples collected from 70 carob (Ceratonia siliqua L.) trees in the South‐west of Sicily, Italy. A phylogenetic analysis of Internal Transcribed Spacer (ITS) sequences indicated that all carob isolates belonged to the cluster E of Laetiporus taxonomy. Ten molecular markers based on Single Sequence Repeats (SSRs) designed on the L. sulphureus genome were developed, and isolates were genotyped through High‐resolution Melting (HRM) analysis. High gene diversity (0.581), no correlation between fungal genotype and host tree species and significant correlation between spatial and genetic distance were observed, suggesting an important role of basidiospores in the epidemiology of the fungus and a risk of transmission from a host tree species to the others. Finally, from a prognostic perspective, significant differences among isolates in terms of mycelial growth suggest that in addition to an accurate identification, a phenotypic characterization of isolates affecting trees may also be important. 相似文献
19.
D. J. Morrison 《Forest Pathology》2004,34(1):15-26
The rhizomorph branching habit in soil, competitive saprophytic ability and virulence were determined for 15 species of Armillaria from Europe, North America and Australia and New Zealand. In soil, rhizomorphs of northern hemisphere species branched either monopodially or dichotomously, whereas all five species from Australia and New Zealand branched dichotomously. The dry weight of rhizomorphs produced in soil by isolates of a species and by species was very variable. Species with monopodially branched rhizomorphs had significantly higher saprophytic colonization scores than dichotomously branched species and scores were significantly higher in Garry oak than Douglas‐fir segments and in fresh than autoclaved segments. The damage to Douglas‐fir seedlings caused by isolates of most dichotomously branched species was significantly greater than that caused by monopodially branched species. Species producing dichotomously branched rhizomorphs were more aggressive than monopodially branched species, killing 80% (vs. 17%) of seedlings that died during the first year of the 2‐year experiment. 相似文献
20.
The density of Armillaria gallica epiphytic rhizomorphs on tree collar was mapped in a young stand of pedunculate oaks (Quercus robur). A quick method to estimate the rhizomorph density was developed, investigating 19 trees, and was used in the subsequent study. The method consists of measuring the frequency of rhizomorphs present on a grid applied to an exposed small area of the tree collar. The pattern in tree collar rhizomorph density was closely related to the pattern of stump colonization by Armillaria and stumps were therefore important as inoculum sources. Rhizomorph density on tree collar showed a strong aggregated spatial pattern which could not be explained by variability in the soil characteristics, in particular waterlogging, or by a spatial pattern in tree vigour. Moreover, rhizomorph density on tree collar did not depend on their dominance status. 相似文献