bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of European Armillaria species by analysis of isozyme profiles
Authors: Bragaloni M. , Anselmi N. , Cellerino G. P. 
Published: June 2007

SummaryStudies were carried out to test the possibility of identifying European Armillaria species by using isozyme patterns. Twenty‐two different enzymes were used to analyse the haploid and diploid mycelium extract of Armillaria borealis, Armillaria cepistipes, Armillaria gallica, Armillaria mellea, Armillaria ostoyae and Armillaria tahescens. Tests for fumarase (E.C. 4.2.1.1.), aconitase (E.C. 4.2.1.3.), leucine‐amino peptidase (E.C. 3.4.11.1.), isocitrate dehydrogenase (E.C. 1.1.1.42.), shikimic dehydrogenase (E.C. 1.1.1.25), glucose‐6‐P‐dehydrogenase (E.C. 1.1.1.49.), malic enzyme (E.C. 1.1.1.40.), 6‐P‐gluconic dehydrogenase (E.C. 1.1.4.4.), pectin esterase (E.C. 3.1.1.11.), and pectic lyase (E.C. 4.2.99.3.) did not reveal enzyme activity. Isozyme profiles of acid phosphatase (E.C. 3.1.3.2.), phospho‐gluco‐isomerase (E.C. 5.3.1.9.), peroxidase (E.C. 1.11.1.7.), polyphenoloxidase (E.C. 1.14.18.), malic dehydrogenase (E.C. 1.1.1.37.), glutamic dehydrogenase (E.C. 1.4.1.3.) and superoxide dismutase (E.C. 1.15.1.1.) were ineffective for species identification. In contrast, esterase (E.C. 3.1.1.1.), glutamic‐oxalacetic transaminase (2.6.1.1.), phospho‐gluco‐mutase (E.C. 2.7.5.1.), alcohol dehydrogenase (E.C. 1.1.1.1.), and polygalacturonase (E.C. 3.2.1.15.) isoenzyme patterns showed enough polymorphism to allow the identification of the different Armillaria species. However, it is necessary to compare several enzyme profiles for a conclusive identification.Intraspecific crosses of A tabescens were confirmed by the presence of a heteromeric isozyme pattern of alcohol dehydrogenase and phospho‐gluco‐mutase.
Somatic incompatibility among African Armillaria isolates
Authors: Abomo‐Ndongo S. , Guillaumin J.‐J. 
Published: June 2007

SummaryTwenty‐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.
Identification of the genus Armillaria by specific amplification of an rDNA‐ITS fragment and evaluation of genetic variation within A. ostoyae by rDNA‐RFLP and RAPD analysis
Authors: Schulze S. , Bahnweg G. , Möller E. M. , Sandermann H. 
Published: June 2007

SummaryGenetic variation among Armillaria ostoyae isolates was studied by rDNA‐restriction fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD) analysis. A total of 20 A. ostoyae isolates, mainly obtained from Picea spp. of different geographical origins, were examined. Southern hybridization of whole‐cell DNAs digested with AvaII and probed with biotin‐labelled cloned rDNA from Saccharomyces carlsbergensis allowed the differentiation of five RFLP groups. UPGMA cluster analysis of RAPD profiles (138 scorable bands) generated by 10 decamer primers (OPA 01‐OPA 10) grouped the isolates in subclusters at similarity levels between 40% and 96%, indicating high intraspecific genetic variability. Some isolates of different geographical origins subgrouped together, suggesting that similar mutational events have occurred independently and that genetic exchange and recombination occurs among the DNAs in natural populations. The potential role of historical and current spread of spruce plants on the genetic variation of A. ostoyae isolates in Europe is discussed. Using the primer pair ARM‐1 and ARM‐2, an Armillaria‐specific ITS‐DNA fragment of about 660 bp was obtained. No intraspecific RFLP of this amplicon could be revealed, indicating low genetic variability of this region.The established informative RFLP and RAPD markers and also the Armillaria‐specific ITS‐DNA fragment may be powerful tools for further epidemiological, phylogenetic and host‐pathogen interaction studies with A. ostoyae.
Abies sibirica in the Ural region is attacked by the S type of Heterobasidion annosum
Authors: Korhonen K. , Fedorov N. I. , Porta N. La , Kovbasa N. P. 
Published: June 2007

SummarySpecimens of Heterobasidion annosum were collected in seven mixed stands of Abies sibirica and Picea abies in Yekaterinburg and Perm regions on the western side of the Ural Mountains, Russia. Pure cultures were isolated from 60 collections and identified in mating tests. Only the S intersterility group was found, attacking both fir and spruce. Based on the appearance of clamp connections in matings, the compatibility of 12 homokaryons from the Ural area with 14 S group homokaryons from western Europe was 100%, with 13 F group homokaryons from southern Europe 76% and 9 P group homokaryons from western Europe 3%. The results show that A. sibirica, in contrast to A. alba, is very susceptible to the S type H. annosum.
Histological analyses of the host response of two aspen genotypes to wounding and inoculation with Hypoxylon mammatum
Authors: Enebak S. A. , Bucciarelli B. , Ostry M. E. , Li B. 
Published: June 2007

SummaryRamets derived from root sprouts of two quaking aspen (Populus tremuloides) parents were either mechanically wounded or wounded and inoculated with mycelium of Hypoxylon mammatum. Female aspen parents were considered either resistant or susceptible based on a 30‐year field trial of their open‐pollinated progenies that had 21% and 93% mortality, respectively, caused by H. mammatum. Each stem was wounded twice at the base and in the nonlignified zone. Samples were taken 5 mm above the site of wounding at 7 and 14 days. Histochemicals used were phloroglucinol‐HCl and Sudan Black B to detect lignin and suberin, respectively. Thin sections of the resistant aspen ramets showed intensive staining phloroglucinol‐HCl, which was localized along both sides of the wound margin. Collenchyma callus was well developed by day 7 and was derived from the phloem tissue internal to the cell walls staining positive for phloroglucinol‐HCl, near the vascular cambium. In contrast, the tissues of susceptible aspen ramets were less stained, the stained cells were less scattered and less collenchyma callus had formed than on the resistant ramets. The presence of the fungus increased the amount of staining observed with phloroglucinol‐HCl and delayed wound closure in both aspen genotypes. No distinguishing pattern could be identified between the two aspen genotypes with respect to suberin formation. When comparing stem response to phloroglucinol‐HCl with respect to the tissue type on the same stem (succulent versus woody), the inoculation of older woody tissue resulted in a more defined host response and thus were better in separating the two aspen genotypes.
Colonization patterns and topochemical aspects of sap streak caused by Stereum sanguinolentum in Norway spruce
Authors: Kleist G. , Seehann G. 
Published: June 2007

SummaryFresh sapwood blocks of Norway spruce (Picea abies) were exposed to 12‐ and 60‐day attack by Stereum sanguinolentum in pure culture and were examined with respect to structural, topochemical and colour alterations. Final stages of degradation by 5. sanguinolentum were studied on naturally decayed spruce wood after 1 year of fungal growth. The development of discoloration in the main anatomical directions of wood was assessed. Furthermore, microspectrophotometrical studies on the decomposition of cell wall polyphenols were performed. Initial signs of sap streak appeared already 8 days after fungal infection. Within the three‐dimensional decay pattern, mycelial aggregations associ‐ated with the ray tissue proved to be the major cause of discoloration. UV extinction measurements taken at 280 nm of different parts of cell wall transverse sections revealed a specific pattern of lignin distribution and its derivatives during fungal degradation.
Similarity between fungi identified as Diplodia pinea f. sp. cupressi in Israel and Botryosphaeria stevensii or Diplodia mutila on Juniperus in the United States
Authors: Stanosz G. R. , Swart W. J. , Smith D. R. 
Published: June 2007

SummaryA fungus identified as Botryosphaeria stevensii (anamorph Diplodia mutila) causes a canker disease that results in dieback of Juniperus species in the United States. A fungus identified as Diplodia pinea f. sp. cupressi causes a similar disease of Cupressus species in Israel and elsewhere. Cultural characteristics, pycnidia, and conidia of isolates of these two pathogens were compared. The ability of each fungus to produce cankers on Cupressus sempervirens was tested. Random amplified polymorphic DNA (RAPD) marker patterns also were analysed, using Sphaeropsis sapinea (syn. Diplodia pinea) isolates as an outgroup. Results indicate the fungus identified as D. pinea f. sp. cupressi from cypress in Israel is the same as, or at least highly similar to, the fungus identified as B. stevensii (or D. mutila) from juniper in the United States. Analysis of RAPD markers indicates relatively low similarity between these isolates and those of S. sapinea. Because these results are consistent with a previously published report describing substantial morphological and isozyme differences between isolates identified as D. pinea f. sp. cupressi and those of S. sapinea, use of the name D. pinea f. sp. cupressi should be abandoned. Inconsistencies between these isolates from juniper and cypress and published descriptions of B. stevensii and D. mutila, however, indicate the need for additional investigation into the relationship of these fungi.
Corresponding patterns of site quality, decline and tree growth in a sessile oak stand
Authors: Standová r T. , Somogyi Z. 
Published: June 2007

SummaryThis study focuses on two rarely studied aspects of oak decline: relations with site characteristics and effects on tree growth. The study was carried out in a 5.5 ha stand in Hungary which is strongly affected by oak decline. The nearly pure sessile oak (Quercus petraea) stand of mostly coppice origin was 90 years old at the beginning of the study. Within‐stand site heterogeneity was described by the herbaceous vegetation. Four ecological site types were distinguished by the species composition of herbs, and characterized by the ecological indicator values of the species. Tree growth between 1987 and 1993 was measured, and tree vigour was estimated from visual characteristics five times between 1987 and 1993. Potential volume increment of declining trees was estimated with the growth rates of healthy trees of the same size. Volume increment loss caused by oak decline was also assessed. Significant positive relationships were found between tree vigour and tree size and between tree vigour and tree growth. The growth of seriously declining trees dropped to almost one‐half of that of healthy ones. Growth reduction of living trees at the stand level amounted to 5.4%, whereas growth reduction of all trees, including those that died during the observation period, amounted to 19.9% of the potential growth. Tree size and growth were greater on better sites. A strong relationship was also found between tree vigour and site type, but sessile oak was more susceptible to decline at better sites.
A review of exapted resistance to diseases of Populus
Authors: Newcombe G. 
Published: June 2007

SummaryThe cultivation of hybrid poplar in the Pacific North‐west (PNW) has expanded in the last 15 years. Native Populus trichocarpa is susceptible to many pests and fungal pathogens but its interspecific hybrids were largely disease‐free until 1991 when Melampsora medusae f. sp. deltoidae first appeared in the region. Genetic analyses of resistance in the PNW, and elsewhere, reveal a pattern whereby genes for resistance are inherited in interspecific hybrids from the exotic, noncoevolved Populus parent. With some pathogen/poplar hybrid combinations, this resistance segregates in the F1 generation, but with others, only in the F2. Such exapted resistance is now known to occur in P. trichocarpa (versus the exotic, eastern North American rust species, M. medusae f. sp. deltoidae), in Populus deltoides (versus the Eurasian rust, Melampsora larici‐populina, the PNW population of Septoria populicola, and an undescribed PNW eriophyid mite), and in Populus maximowiczii (versus Melampsora occidentalis, and the PNW populations of Venturia populina, S. populicola, and Linospora tetraspora).
Resistance of new Belgian poplar clones to British isolates of the bacterial canker pathogen, Xanthomonas populi
Authors: Lonsdale D. , Rose J. 
Published: June 2007

SummaryForty‐nine new poplar clones, bred in Belgium and screened there for resistance to bacterial canker caused by Xanthomonas populi, were additionally screened in southern England, using British isolates of the bacterium. Thirty‐five of the test clones ranked better than the clone ‘Boelare’, which is already registered in the UK as an approved clone, and is regarded as having acceptable resistance. The registered clone ‘Ghoy’ was more susceptible, and outranked only four test clones. Preliminary measurements of canker length and stem girdling index showed differences between five bacterial isolates.
Melampsora and Marssonina pathogens of poplars and willows in New Zealand
Authors: Spiers A. G. 
Published: June 2007

SummaryNew Zealand has hosted three Melampsora species attacking poplars (Populus spp.), namely, Melampsora larici‐populina, Melampsora medusae and for a single season, Melampsora medusae‐populina, a unique interspecific hybrid. The predominant species, M. larici‐populina, over‐winters via larch and each year new races appear causing defoliation of previously rust‐resistant cultivars. Melampsora medusae also occurs in some seasons following over‐wintering on certain hosts or by aerial transport from Australia. Willows (Salix spp.) host four Melampsora species, Melampsora coleosporioides, Melampsora epitea var. epitea and two unidentified species attacking Salix viminalis and Salix daphnoides/Salix incana× open pollinated hybrids, respectively. The host range and pathogenicity of these species have remained static as no breakdown in host resistance has been observed. The anthracnose fungi, Marssonina brunnea and Marssonina castagnei on poplar, and Marssonina salicicola on tree willows occur throughout New Zealand. All three species can cause severe defoliation of susceptible cultivars in moist districts where annual rainfall exceeds 1000 mm. Although all form abundant microconidia during autumn, the Drepanopeziza states have never been observed in New Zealand. During an unusually wet summer (199–93), a new strain of Marssonina salicicoa appeared which defoliated the previously resistant cultivar, salix matsudana × salix alba cv. 1002 The importance of monitoring the morphological (conidial dimensions, DNA fingerprints) and physiological (host range and pathogenicity) attributes of local populations of Melampsora and Marssonina species is discussed.
Short rotation coppice willow in Northern Ireland since 1973: development of the use of mixtures in the control of foliar rust (Melampsora spp.)
Authors: McCracken A. R. , Dawson W. M. 
Published: June 2007

SummaryA review is given of the use of clonal mixtures in the development of disease control strategies in short rotation coppice willow in Northern Ireland. Salix burjatica‘Korso’ had been grown successfully for over 10 years when, in 1985, Melampsora epitea var. epitea caused serious problems. Although fungicides were effective, their use was not practical for environmental and economic reasons. Therefore, in 1987 large scale field experiments were initiated to investigate the use of clonal mixtures as a disease control strategy. Increased yields were consistently recorded from mixed stands when compared to either the mean yield of component clones or the individual yields of any of the component clones grown in monoculture. Part of this increased yield was due to a reduction in the impact of rust disease. Investigations are currently being conducted on the effect of number of clones within a mixture, the best clones to use and the optimum planting density. It is essential that there is a range of susceptibilities to M. epitea var. epitea pathotypes within the components of the mixture.
Relative susceptibility of Salix clones to chrysomelid beetles: evidence from the Stott willow collection at Ness
Authors: Hodkinson I. D. , Flynn D. H. , Shackel S. C. 
Published: June 2007

SummaryWillow species and hybrids growing in the Stott willow collection at Ness, UK, differed markedly in their susceptibility to leaf damage by insects, predominantly chrysomelid beetles, with the rank order of susceptibility remaining relatively constant over 2 years. Some species displayed a wide range of variation in susceptibility amongst clones; others very little. The range of susceptibilities of hybrids tended to mirror those of the parent species, with the hybrid usually sustaining leaf damage levels intermediate between those of the parents. Leaf damage in most species was higher on the lower leaf surface up to mid‐season, beyond which leaf perforation damage became prevalent. Damage levels did not appear related to leaf toughness. Apparent levels of leaf damage were lower in October versus July/August samples across nearly all species. Heavy leaf damage in one year did not appear to induce the production of leaves that were more resistant to insect attack in the following year.
Discoloration following bark stripping wounds on Fraxinus excelsior
Authors: Vasiliauskas R. , Stenlid J. 
Published: June 2007

SummaryA total of 101 Fraxinus excelsior trees 8–32 cm in d.b.h. with bark stripping wounds caused by Alces alces and Cervus elaphus in Lithuania were cut, dissected and examined. The injuries ranged in age from 5 to 18 years, when the trees were 22–40 years old and were in the size range 6–24 cm d.b.h. For 5‐10 years old wounds, the mean length of associated wood discoloration was 804 × 201 cm, while in 16–18 years old wounds it was 912 × 144 cm. There was no correlation between wound age and extent of discoloration in the stems examined (r = 0.11). Tree d.b.h. and wound size (initial width × length) were correlated with the extent of discoloration (r = 0.43 and r = 0.20, respectively). The presence of complete wound occlusion had no significant effect on the length of columns of discoloration associated with wounds of 10 or more years old. The average occlusion rate during the first 10 years was 128 × 28 mm or 13 mm/year, correlating positively with the radial increment (r = 0.42). Amongst a total of 500 F. excelsior trees with wounds, 29 trees (5.8%) bore basidiomycete fruiting bodies. Most common was Phellinus punctatus, found on 12 (2.4%) stems, followed by Coniophora puteana (1.6%), Peniophora limitata (0.4%) and Datronia mollis (0.4%). Fungi most commonly isolated from discoloured wood were ascomycetes Phaeoacremonium rubrigenum, Phialophora malorum, Hypoxylon rubiginosum, Coniothyrium sporulosum, Libertella spp., Ophiostoma sp., and basidiomycetes Ischnoderma benzoinum, Ischnoderma resinosum, Tyromyces sp.
Effects of vitality fertilization on the growth of Heterobasidion annosum in Norway spruce roots
Authors: Piri T. 
Published: June 2007

SummaryThe effects of vitality fertilization on the growth of Heterobasidion annosum in roots of Norway spruce (Picea abies) were studied in a 53‐year‐old, naturally regenerated spruce stand in southern Finland. The fertilizer treatments were: (1), unfertilized control; (2), a compound fertilizer containing P, K, Ca, Mg, S, Cu, Zn and B; (3), as 2 with additional nitrogen; (4), as 3 with additional lime; and (5), a mixture composed on the basis of needle analysis, containing N, P, K and Cu. Three growing seasons after fertilization, four roots of eight trees in each treatment were inoculated with four different strains of H. annosum. Spread of the fungus from the inoculation point was determined after 12 months. Mean spread rates upwards in roots were 18.2, 25.6, 21.3, 26.0 and 29.8 cm/year in treatments 1, 2, 3, 4 and 5, respectively. These results suggest a tendency towards faster growth by H. annosum in fertilized trees. However, there was considerable variation in fungal growth at both the tree and root level and differences between treatments were not statistically significant.
Induction of phenylalanine ammonia lyase activity and control of Sphaeropsis sapinea infection in Pinus radiata by 5‐chlorosalicylic acid
Authors: Reglinski T. , Stavely F. J. L. , Taylor J. T. 
Published: June 2007

SummaryPhenylalanine ammonia lyase (PAL) activity increased rapidly in Pinus radiata seedlings after treatment with 2 mm 5‐chlorosalicylic acid (5CSA) and peaked after 48 h at four‐times the level of the control. Elevation of PAF is often associated with the induction of host resistance mechanisms. Thus, effects of 5CSA on subsequent infection of P. radiata by Sphaeropsis sapinea was investigated. Only one out of 16 seedlings treated with 2 mm 5CSA, 4 days before inoculation, developed deadtop compared to 14 of the controls. The 5CSA was directly inhibitory at this concentration and reduced growth rate of S. sapinea on agar by 27%. However, antifungal activity does not fully account for the observed disease control afforded by 5CSA since 0.5 mm and 0.25 mm 5CSA, which did not inhibit growth of S. sapinea, significantly reduced the incidence of deadtop. Furthermore, 1 mm 5CSA protected seedlings against fresh inoculation challenge for up to 32 days after application. Such durable resistance is unlikely to be attributable to the direct effects of the applied compound and may suggest the involvement of inducible host resistance mechanisms.
Hebeloma inoculation on Norway spruce seedlings in solarized and infested soil
Authors: Annesi T. , Motta E. 
Published: June 2007

SummaryThe effect of inoculation of Hebeloma sp. on the growth of Norway spruce (Picea abies) seedlings was studied, in a controlled environment, with soil samples naturally infested by Pythium spp., Fusarium spp. and Rhizoctonia solani, and with samples of soil in which the pathogens had been controlled by solarization. The best results were obtained in solarized soil, but mycorrhizae also enhanced plant growth in the presence of the whole soil‐borne mycoflora. The combined use of inoeulation of a mycorrhizal fungus and solarization is discussed.
Pre‐penetration behaviour of the urediniospores of birch rust, Melampsoridium betulinum, on greenhouse‐grown and microcultured leaves of Betula spp.
Authors: Poteri M. , Ryynänen L. 
Published: June 2007

SummaryIn two different experiments the urediniospores of Melampsoridium betulinum from Betula pendula and Betula pubescens germinated both on mature leaves of greenhouse‐grown plants and on sterile in vitro leaves of micropropagated plantlets, which were cloned from the same B. pendula and B. pubescens genotypes. The urediniospores and germ tubes were more easily detached from the leaf surfaces of in vitro leaves. If germination took place on a leaf vein, the growth continued across the veinal ridges; otherwise, no determined growth towards the stomata could be observed with either of the leaf types studied. In both experiments on the in vitro leaves of B. pubescens clone V5944, the germ tubes of the rust isolate from B. pendula mislocated appressoria significantly more often than the germ tubes of the rust isolate from B. pubescens. On the mature leaves of B. pendula clone E4214 and B. pubescens clone V5940 there were also significant differences in appressorial locations between the two rust isolates but the clonal responses were inconsistent. The results of the inoculations suggest that the incompatibility of the rust isolates from B. pendula on the leaves of B. pubescens is not related to the significantly higher ratio of failures in locating appressoria in this host‐rust combination.