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1.
To determine the phylogenetic positions of two new species, Armillaria jezoensis and Armillaria singula, and one new subspecies, Armillaria mellea suhsp. nipponica, the nucleotide sequences of the intergenic spacers (IGS) of their ribosomal DNA were investigated, and compared with those of tour other Armillaria species from Japan, and those of nine Armillaria species from Europe and North America. We conclude that Armillaria jezoensis, and Armillaria singula belong to the Armillaria gallica cluster as Armillaria cepistipes, Armillaria gallica and Armillaria sinapina from Japan. Two isolates of Armillaria ostoyae from Japan were placed within the Armillaria ostoyae cluster. Armillaria mellea subsp. nipponica had an IGS sequence as long as the IGS of Armillaria mellea from Europe and North America. However, the IGS sequences of Armillaria mellea subsp. nipponica, whose basidium base lacks a clamp connection could not be satisfactorily aligned with the IGS sequences of other species possessing this morphological feature.  相似文献   

2.
Distribution, host preference and pathogenicity of Japanese Armillaria species on conifers were investigated on the basis of field collections of 65 isolates. We identified seven Armillaria species from 19 conifer species including six major Japanese plantation conifers using mating tests and sequences of the translation elongation‐1 α gene. Armillaria mellea, Armillaria ostoyae, Armillaria cepistipes and Armillaria sinapina were frequently collected, whereas Armillaria nabsnona, Armillaria tabescens and a biological species Nagasawa’s E were rare. On the basis of host condition when the isolates were collected, A. mellea, A. ostoyae, A. cepistipes and A. tabescens are considered as moderate to aggressive pathogens of conifers in Japan.  相似文献   

3.
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   

4.
Twenty-five African Armillaria isolates paired on malt-agar were divided into four groups on the basis of somatic incompatibility reactions. One of the groups is similar to the European species Armillaria mellea, while another group is provisionally designated as Armillaria heimii.  相似文献   

5.
Polyacrylamide isoelectric focusing with specific staining for laccase activity was used to characterize laccase from European Armillaria species (Armillaria ostoyae, Armillaria mellea, Armillaria gallica, Armillaria cepistipes). The enzyme was extracted from culture media either supplemented, or not, with pine sawdust, and also from Pinus pinaster naturally infected by A. ostoyae, or artificially inoculated with A. mellea and A. ostoyae. Some differences in banding patterns were found for Armillana isolates according to the species and the culture media, but a common band at pI = 3.4 was found in all the extracts tested, independently of their origin (culture filtrate or wood).  相似文献   

6.
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   

7.
Attempts to design species‐specific PCR primers from six European Armillaria species in the ribosomal RNA genes are reported. Primers were developed on the basis of the nucleotide sequence variability of the internal transcribed spacers (ITS) and the intergenic spacer (IGS1) of the ribosomal DNA. Four sets of primers gave specific PCR products for Armillaria tabescens, Armillaria mellea and Armillaria ostoyae. However, due to the high sequence similarities between Armillaria borealis and Armillaria ostoyae and between Armillaria cepistipes and Armillaria gallica no species specific amplification was obtained for these taxa.  相似文献   

8.
Investigation of nitrogen nutrition in different strains of Armillaria mellea. I. Utilisation of different sources of nitrogen. The assimilation of different forms of nitrogen - NO3-, NH4+ and L-asparagine by isolates of Armillaria mellea from France and Poland was investigated. Both the growth aspect, in which mycelial biomass production was related to the utilisation of nitrogen sources, and the morphological aspect, involving aerial mycelium, sclerotia and rhizomorphs, were studied. Significantly difterent effects were recorded for the influence of nitrogen source, the period of growth and their interaction on the growth of various isolates. Different nitrogen sources significantly affected sclerotial and rhizomorph formation. Isolates of A. mellea, geographically and genetically different, were shown to be also physiologically specialised as was also C. tabescens.  相似文献   

9.
The overall aim of this study was to develop a new, reliable and rapid diagnostic assay for differentiating six European Armillaria species based on variation in their elongation factor‐1 alpha (EF‐1 α) gene sequences and to verify a set of species‐specific primers on 61 Armillaria isolates from Europe. Partial sequences of the EF‐1 α gene obtained in Armillaria borealis, Armillaria cepistipes, Armillaria gallica, Armillaria mellea, Armillaria ostoyae and Armillaria tabescens revealed sufficient interspecific variation to distinguish among species using nested primers. These primers gave unambiguous bands when tested on representative isolates of five of these species. However, the EF‐1 α sequences of European A. borealis isolates clustered into two distinct clades, termed here AbX and AbY. Specific primers were subsequently designed and tested successfully on both AbX‐type and AbY‐type A. borealis isolates. The taxonomy of A. borealis needs to be elucidated to determine whether a new, as yet unnamed Armillaria taxon exists in Europe. Three A. borealis isolates were also found to have heterozygous sites in their EF‐1 α sequences, which suggests that the gene could exist in more than one copy or that these isolates contain hybrid sequences. A pyrosequencing method was also developed, targeting a small region of EF‐1 α intron 4, which was able to differentiate European Armillaria isolates to the species level and additionally could distinguish AbX‐type and AbY‐type A. borealis isolates.  相似文献   

10.
Penetration of root bark tissues of Picea sitchensis by Armillaria ostoyae, Armillaria mellea and Heterobasidion annosum was examined in the absence of wounds, in superficial wounds (rhytidome tissues removed to expose the secondary phloem) and in wounds to the depth of the vascular cambium (deep wounding). Both species of Armillaria penetrated bark without prior wounding, but neither species formed rhizomorphs in this treatment. Armillaria ostoyae penetrated to 39 cell layers in depth by 48 days after inoculation of unwounded bark, whereas A. mellea penetrated 25 cell layers in the same time. Armillaria mellea penetrated superficial wounds significantly more rapidly than did A. ostoyae. Both species produced rhizomorphs within wounded host tissues. Inoculation of deep wounds with Armillaria resulted in a greater depth of bark necrosis with A. mellea than with A. ostoyae. In the absence of wounding, H. annosum failed to penetrate root bark tissues, but in both superficial and deep wounds hyphae penetrated beyond the ligno–suberized boundary zone (LSZ) by 12 days after inoculation. Where no inoculations were made, superficial or deep wounding led within 25 days to the restoration of a structurally continuous LSZ, and by day 48 the wound periderm (WP) was fully differentiated. In inoculated wounds, however, formation of the LSZ and WP was delayed or inhibited in most trees, particularly following inoculation with A. ostoyae or A. mellea. Suberization in the LSZ and WP remained diffuse and discontinuous 48 days after inoculation. Moreover, the presence of WP did not prevent further penetration of the tissues by the pathogens. Variations between trees in the depth of pathogen penetration were noted, possibly indicating differing susceptibilities of individual host genotypes. The possible host factors involved in resistance to penetration of root bark tissues by Armillaria and Heterobasidion are discussed.  相似文献   

11.
Armillaria root rot is a well‐known disease on a wide range of plants, world‐wide. In Ethiopia, the disease has previously been reported on Pinus spp., Coffea arabica and on various native hardwoods. The causal agent of the disease has been attributed to Armillaria mellea, a species now known to represent a complex of many different taxa. The aim of this study was to determine the extent of Armillaria root rot and the identity of the Armillaria sp. in Ethiopian plantations. As part of a plantation disease survey in 2000 and 2001, samples were collected in plantations at and around Munessa Shashemene, Wondo Genet, Jima, Mizan and Bedele, in south and south‐western Ethiopia. Basidiocarps were collected and their morphology studied. Morphological identification was confirmed by sequencing the intergenic spacer (IGS‐1) region of the ribosomal rRNA operon and comparing data with published sequences of Armillaria spp. Armillaria isolates were collected from Acacia abyssinica, Pinus patula, Cedrela odorata and Cordia alliodora trees. Sporocarps were found on stumps of native Juniperus excelsa. Basidiocarp morphology and sequence data suggested that the fungus in Ethiopia is similar to that causing disease of Pinus spp. in South Africa and previously identified as A. fuscipes. This identification was confirmed for all isolates, based on sequence data. Armillaria fuscipes is known to be common in southern Africa. Its widespread occurrence in Ethiopia suggests that it is also the major cause of Armillaria root rot in that country.  相似文献   

12.
Studies on the nitrogen nutrition of several strains of Armillaria mella. II. The influence of different concentrations of carbon and of nitrogen (C:N). Mycelial production and the morphology of several isolates of Armillaria mellea and Clitocybe tabascens was investigated in relation to different concentrations of carbon (D-glucose) and nitrogen (L-asparagine) in the medium. The role of carbon and nitrogen and of the proportions C:N in the process of rhizomorphogenesis was established. Mycelial production and initiation and development of rhizo-  相似文献   

13.
Incidence of peach [Prunus persica (L.) Batsch] tree mortality attributed to Armillaria root disease was assessed from 2009 to 2011 in 15 orchards in the State of Mexico, Mexico. Incidence increased gradually every year of assessment, reaching average values of 9.7, 15.3 and 20.3% tree mortality and 23.2, 24.7 and 28.3% disease‐impacted area of the orchards during 2009, 2010 and 2011, respectively. The cultivars ‘Nemaguard’ and ‘Criollo of La Goleta’, a local rootstock used in the region, were both susceptible to the disease. To identify species of Armillaria isolated from infected peach trees, two nuclear rDNA regions (partial 5.8S‐ITS2‐LSU D‐domains and partial 3′ LSU‐IGS1) and the translation elongation factor‐1α (tef‐1α) gene were sequenced and compared with sequences of known Armillaria species. DNA sequence analysis from 49 Armillaria isolates revealed that five isolates (10.2%) were Armillaria mellea and eight isolates (16.3%) were Armillaria gallica. DNA sequences from the remaining 36 isolates (73.5%) showed no close similarity to Armillaria sequences in GenBank, and apparently represent an undescribed Armillaria species. This undescribed species was the most widely distributed in the region of study. Separate phylogenetic analyses of the LSU region (D1–D3 domains concatenated with the partial 3′ end) and the tef‐1α region show that the undescribed species is quite distinct from other Armillaria spp. reported in North America.  相似文献   

14.
Armillaria species from Japan were characterized using polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) of the intergenic spacer region-1 (IGS-1) of ribosomal DNA (rDNA). Eleven different digestion patterns by restriction endonuclease Alu I were found among 70 isolates of seven Armillaria species in Japan. Isolates within Armillaria nabsnona, A. ostoyae, A. cepistipes, and Japanese biological species E showed the same Alu I digestion patterns. Five Alu I patterns were detected for A. gallica, three patterns for A. mellea, and two patterns for A. tabescens. Seven Armillaria species in Japan were clearly distinguished by using the profiles obtained when PCR products were digested with Alu I, Msp I, and Hae III restriction enzymes. There was considerable variability of Alu I restriction sites within the IGS-1 between the isolates of five Armillaria species, A. gallica, A. nabsnona, A. cepistipes, A. mellea, and A. tabescens, in Japan and those of their European and North American counterparts.  相似文献   

15.
Five Armillaria species were identified in a nationwide survey in Greece. Armillaria mellea was present in coniferous and broad-leaved forests in most of the areas examined, except the high altitudes (above 1100 m) of the mountains of north Greece. It was found to cause significant damage in fir forests as well as in fruit orchards and vineyards. Armillaria gallica was common in coniferous and broad-leaved forests in the high altitudes of central and northern Greece, predominating in the beech forests. The fungus was a weak parasite or a saprophyte of forest trees and was occasionally found on cultivated plants. Armillaria ostoyae was not found in southern and central parts of the country, but it has a wide distribution in the mountain forests of northern Greece and causes significant damage on fir, black pine, Scots pine and spruce. Armillaria cepistipes was recorded at high altitudes (1400–1800 m) on two mountains of northern Greece, mostly as a saprophyte in coniferous and broad-leaved forests. Armillaria tabescens was rare in the forests of Greece; it was found to cause disease in almond tree orchards.  相似文献   

16.
The production of rhizomorphs by Armillaria mellea from stumps samples collected in East Anglia was studied: those of broad-leaved trees produced greater yields than those of pines and, in the absence of poisoning, over a much longer period after felling. The ability of A. mellea to form rhizomorphs is often reduced after prolonged growth in pine tissues. The interaction of A. mellea and other fungi is briefly considered. Some implications of these observations for forestry practice are discussed.  相似文献   

17.
A stand otPicea abies (L.) Karst. was studied using the method of tree-ring analysis. The stand involved non-infected trees and trees at different stages of infection by the wood-destroying fungus Armillaria mellea (Vahl. ex Fr.) Kummer [Armillariella mellea (Vahl.) Karst.].  相似文献   

18.
Species of Armillaria were identified from 645 isolates obtained in a nation‐wide survey in Albania. The material was collected from ca. 250 permanent plots, established for monitoring forest health, and from forests and orchards attacked by Armillaria. Armillaria mellea s.s. occurred on several coniferous and broadleaved trees in most areas examined, although it was absent above 1100–1200 m in northern Albania. This species damaged Abies and Quercus spp. and, to a lesser extent, other forest trees. Armillaria mellea was also commonly recorded causing damage in orchards and vineyards. Armillaria gallica was a common saprophyte or weak pathogen in coniferous and deciduous forests at altitudes from 600 to 1600 m, and less commonly on oaks at lower altitudes. Armillaria ostoyae was rare in central and southern Albania, but common in northern Albania, causing significant damage to pine and other conifers, mostly at altitudes from 600 to 1800 m. Armillaria cepistipes was recorded at altitudes from 800 to 1800 m as a saprophyte or weak pathogen on conifers and deciduous trees, mostly in beech and silver fir forests. Armillaria tabescens was found in oak forests at altitudes from sea level to 900 m. In orchards, A. tabescens occasionally attacked almond and pear trees. Armillaria borealis was found in a few locations in northern Albania, at altitudes from 800 to 1800 m.  相似文献   

19.
Laccase and manganese-dependent peroxidase (Mn peroxidase) activities were detected in the culture media of Armillaria ostoyae and A. mellea. Mn peroxidase was produced in significantly higher quantity by the A. ostoyae isolates and was purified by chromatography from one isolate of this species. Some properties of the purified enzyme were examined (absorption spectrum, H2O2 and MnSO4 optimal concentrations, pH optimum and lactate stimulation). Enzymes of potential importance in the lignin degradation (especially Mn peroxidase) by Armillaria sp. are compared to those of other root-rotting fungi. The possible role of Mn peroxidase in modulating the pathogenicity of Armillaria sp. is discussed.  相似文献   

20.
Armillaria root disease is a contributing factor to oak decline in the Ozark Mountains of central USA. We have identified Armillaria gallica, Armillaria mellea, and Armillaria tabescens in Quercus‐Carya‐Pinus forests of the region. Presence/absence patterns of each Armillaria species as well as all possible Armillaria species combinations were analysed by contingency tables and/or stepwise logistic multiple regressions with principal characteristics of the studied sites and forest stands, both quantitative and qualitative: geographic land‐type association, bedrock type, landform position, slope direction (aspect), soil type and soil surface stone cover, down woody debris, abundance and basal area of woody vegetation and decline mortality by species. Most decline mortality consisted of two red oak species (section Erythrobalanus, Quercus coccinea and Quercus velutina), which also were most sensitive to Armillaria infection. Site characteristics related to the distributions of Armillaria species and decline mortality were also related to the preponderance of Q. coccinea and Q. velutina, regional vegetation history (i.e. conversion of Pinus echinata stands to hardwoods), and the different strategies of territory acquisition and spread of the Armillaria species involved. The presence of A. gallica may reduce the activity of more virulent Armillaria species.  相似文献   

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