Species Of Ophiostomatoid Fungi Research Articles

Ophiostomatatoid fungi (Ascomycota) associated with Ips acuminatus (Coleoptera) in eastern Poland

Ips acuminatus (Coleoptera, Scolytinae) is a pine-infesting bark beetle that occurs throughout Europe and Asia. Recently, the insect has killed numerous Scots pines (Pinus sylvestris) in eastern Poland. Several species of ophiostomatoid fungi are associated with I. acuminatus in Europe, but no research has been done on the fungi associated with this bark beetle in Central Europe specifically. The aim of this study was to identify the ophiostomatoid fungal associates of I. acuminatus in eastern Poland, where tree mortality caused by this beetle species has recently increased. Field surveys in Puławy and Mircze Forest Districts yielded a total of 2 269 fungal isolates from 237 beetles and 204 beetle galleries. Isolates were grouped based on morphology and representatives of each group were identified based on DNA sequences of the ITS, LSU, β-tubulin, calmodulin and elongation factor 1-α gene regions. A total of seven previously described species of ophiostomatoid fungi were identified. The dominant species were Graphilbum acuminatum and Sporothrix pseudoabietina. This study revealed that the community of ophiostomatoid fungi associated with I. acuminatus in Poland is different from those reported in other regions of Europe. In addition, molecular data suggest that S. pseudoabietina is a synonym of S. villosa in the Sporothrix gossypina & S. stenoceras species complexes.

Fungi associated with Ips acuminatus (Coleoptera: Curculionidae) in Ukraine with a special emphasis on pathogenicity of ophiostomatoid species

Conifer bark beetles are well known to be associated with fungal complexes, which consist of pathogenic ophiostomatoid fungi as well as obligate saprotroph species. However, there is little information on fungi associated with Ips acuminatus in central and eastern Europe. The aim of the study was to investigate the composition of the fungal communities associated with the pine engraver beetle, I. acuminatus, in the forest-steppe zone in Ukraine and to evaluate the pathogenicity of six associated ophiostomatoid species by inoculating three-year-old Scots pine seedlings with these fungi. In total, 384 adult beetles were collected from under the bark of declining and dead Scots pine trees at two different sites. Fungal culturing from 192 beetles resulted in 447 cultures and direct sequencing of ITS rRNA from 192 beetles in 496 high-quality sequences. Identification of the above revealed that the overall fungal community was composed of 60 species. Among these, the most common were Entomocorticium sp. (24.5%), Diplodia pinea (24.0%), Ophiostoma ips (16.7%), Sydowia polyspora (15.1%), Graphilbum cf rectangulosporium (15.1%), Ophiostoma minus (13.8%) and Cladosporium pini-ponderosae (13.0%). Pathogenicity tests were done using six species of ophiostomatoid fungi, which were inoculated into Scots pine seedlings. All ophiostomatoid fungi tested successfully infected seedlings of Scots pine with varying degrees of virulence. Ophiostoma minus was the only fungus that caused dieback in inoculated seedlings. It is concluded that I. acuminatus vectors a species-rich fungal community including pathogens such as D. pinea and O. minus. The fungal community reported in the present study is different from that reported in other regions of Europe. Pathogenicity tests showed that O. minus was the most virulent causing dieback in seedlings of Scots pine, while other fungi tested appeared to be only slightly pathogenic or completely non-pathogenic.

Ophiostomatoid fungi isolated from fallen shoots of Scots pine pruned by Tomicus species in Poland

Ophiostomatoid fungi are known to be associated with <em>Tomicus</em> spp. on <em>Pinus sylvestris</em>. However, very little is actually known about the fungi present in the pine shoots damaged by these insects. The aim of this study was to survey species of <em>Ophiostoma</em> s.lato associated with fallen shoots of Scots pine pruned by <em>Tomicus</em> spp. in Poland. The study was conducted in four pure Scots pine stands in southern and south-western part of the country. Fungi were identified based on morphology and DNA sequence comparison for two gene (the ITS rDNA region and ß–tubulin). In total, 64 isolates obtained, represent seven species of ophiostomatoid fungi, including their asexual states of the genera. Two of them, <em>Ophiostoma</em> sp. 1 and <em>Sporothrix</em> sp. 1 probably represent new taxa. All species were found at very low frequencies. Among them, <em>Ophiostoma minus, Ophiostoma</em> sp. 1 and <em>Sporothrix</em> sp. 1 were the most frequently isolated, with a frequency of 2.0%. Occasionally, isolated species included <em>Leptographium piriforme, Ophiostoma canum, Ophiostoma floccosum</em> and <em>Grosmannia cucullata</em>-like. Association of species of Ophiostoma s. lato with <em>Tomicus</em> spp. and the taxonomic status of two new species are discussed.

HISTOPATOLOGÍA DEL PINO DE LAS ALTURAS (Pinus hartwegii Lindl.) INOCULADO CON TRES HONGOS OPHIOSTOMATOIDES

The goal of this study was to identify the histological alterations in hartweg pine (Pinus hartwegii) caused by three species of ophiostomatoid fungi by means of light microscopy. There was an accumulation of resin in the inoculated zone within 10 days, and foliage of inoculated seedlings turned yellow and reddish-brown at 60 days. With inoculation of Leptographium guttulatum and Ophiostoma olivaceapinii, it was observed that they induce the metabolization of polyphenols, which were deposited on the cell walls of the inner bark, the phloem, vascular cambium and in the pith, where they became necrotic. Compared to L. guttulatum and O. olivaceapini, O. ips caused a more severe necrosis of the inner bark, cambium, and pith. In the xylem of inoculated seedlings, the hyphae of the three different fungi penetrated into the tracheids and moved through the bordered pits and radially through the parenchyma cells in the rays.

Bark beetle-associated fungi in Fennoscandia with special emphasis on species of Ophiostoma and Grosmannia

Global trade in untreated timber and wood products raises the risk of accidentally introducing forest pests and pathogens into new environments. Bark beetles (Coleoptera: Scolytinae) include several species that are regarded as forest pests. These insects are known to live in close association with fungi, especially species of ophiostomatoid fungi (Ascomycota). Several of these fungi are agents of blue stain in timber, and some are serious plant pathogens. However, only little is known regarding the fungal associates of bark beetles, or the interactions between the fungus, the bark beetle and the host tree in the boreal forests of Fennoscandia. The aim of this study was to increase the knowledge regarding bark beetle-associated fungi in Fennoscandia, with special emphasis on the genera Ophiostoma Syd. & P. Syd. and Grosmannia Goid. Fungi associated with 13 different bark beetle species, infesting Norway spruce (Picea abies (L.) Karst.), Scots pine (Pinus sylvestris L.) and birches (Betula L. spp.) in the eastern parts of Finland and neighboring Russia, as well as southern Norway, were isolated and identified. The fungal identifications were based on morphological characteristics and DNA sequence comparisons. The survey revealed the occurrence of at least 29 species of Ophiostoma and Grosmannia. All the bark beetle species considered in this study were frequently associated with a complex of ophiostomatoid fungi. Several species were recorded for the first time in the countries in the study. A surprisingly high number of previously undescribed fungal species were discovered. During the survey, eight of these species were described as new taxa. In addition, the study revealed new insect-fungus relationships. The number of taxa encountered, covering a relatively small geographical area, indicates that there are many more ophiostomatoid fungi occurring in the boreal forests of Fennoscandia than has previously been recognized. The study emphasizes the importance of developing a clear understanding of the possible threats of moving timber and wood products without knowledge of the micro-organisms that might also be moved.

Ophiostomatoid fungi (Ascomycota) associated with Pinus tabuliformis infested by Dendroctonus valens (Coleoptera) in northern China and an assessment of their pathogenicity on mature trees

Dendroctonus valens is an invasive pest in coniferous forests of northern China. It was suspected of being responsible for the death of more than three million Pinus tabuliformis trees. The present study sought to identify the ophiostomatoid fungi associated with D. valens in northern China and understand the possible role of these fungi in the pine decline. On the basis of morphology, physiology, mating compatibility and phylogenetic analyses of multiple DNA sequences, seven species of ophiostomatoid fungi were isolated from and around D. valens galleries: Leptographium alethinum, Grosmannia koreana (teleomorph of L. koreanum), L. procerum, L. sinoprocerum, L. truncatum, Pesotum aureum and P. pini. All have been recorded for the first time in China. Among them, the occurrence of the dominant species L. procerum is positively linked to attack intensities of D. valens. The pathogenicity of four species (L. koreanum, L. procerum, L. sinoprocerum and L. truncatum) was tested on mature P. tabuliformis trees by stem inoculation. All inoculated strains caused significant necrotic lesions on the inner bark. However, L. koreanum and L. truncatum induced more extensive lesions than L. procerum and L. sinoprocerum. Their association with D. valens and the P. tabuliformis decline is discussed.

Sap-staining fungi from logs and boards of two commercially important pines in Korea

AbstractTo collect more information about the organisms causing sap-stain, a thorough survey was conducted in Koreas sawmills that process logs and boards of Japanese red pine and Korean pine. Sap-staining fungi were isolated and identified using morphological and molecular methods. The 482 isolates obtained were distributed into at least nine species of ophiostomatoid fungi. In both pine species, the frequency of ophiostomatoid isolates was much higher in boards than in logs. Three species, Ophiostoma koreanum,O. floccosum, andO. piliferum, were found on both logs and boards. TwoPesotumspecies from Japanese red pine were isolated only from logs. Our results show that the dominant species in both logs and boards wasO. koreanumfrom Korean pine. However,O. koreanum,O. floccosum, andO. ipswere the most frequently found species in this study.

DNA sequence comparisons of Ophiostoma spp., including Ophiostoma aurorae sp. nov., associated with pine bark beetles in South Africa.

BARK BEETLES (COLEOPTERA: Scolytinae) are well-recognized vectors of Ophiostoma species. Three non-native bark beetle species infest various Pinus species in South Africa, and they are known to carry at least 12 different species of ophiostomatoid fungi. Some of these fungi have not been identified to species level. The aim of this study was to determine or confirm the identities of Ophiostoma species associated with bark beetles in South Africa using comparisons of DNA sequence data. Identities of Ophiostoma ips, O. floccosum, O. pluriannulatum, O. quercus and O. stenoceras were confirmed. Ophiostoma abietinum, O. piliferum and Pesotum fragrans are recognised for the first time and the new species, O. aurorae sp. nov., is described from pine-infesting bark beetles in South Africa.

Ophiostoma stenoceras and O. grandicarpum (Ophiostomatales), first records in the Czech Republic.

Two species of ophiostomatoid fungi were observed in oaks. Ophiostoma stenoceras was isolated during a study of endophytic mycobiota of the roots and seedlings of a sessile oak (Quercus petraea). Ophiostoma grandicarpum was recorded in the stem of a pedunculate oak (Q. robur). These fungi have not yet been reported from the Czech Republic. The knowledge on the occurrence of ophiostomatoid fungi in the Czech Republic is reviewed.

Components of Antagonism and Mutualism inIps pini–Fungal Interactions: Relationship to a Life History of Colonizing Highly Stressed and Dead Trees

Efforts to describe the complex relationships between bark beetles and the ophiosto- matoid (stain) fungi they transport have largely resulted in a dichotomous classiÞcation. These symbioses have been viewed as either mutualistic (i.e., fungi help bark beetles colonize living trees by overcoming tree defenses or by providing nutrients after colonization in return for transport to a host) or antagonistic (i.e., fungi compete for a limited resource and reduce brood development with no apparent beneÞt to the beetle). We investigated several components ofone beetleÐf ungus interaction. SpeciÞcally, we addressed whether beetle entry into, and development within, a host tree vary with the degree ofcolonization by ophiostomatoid fungi. Ips pini (Say) transports several species ofophiostomatoid fungi, the most common being Ophiostoma ips (Rumbold) Nannfeldt, in the process ofcolonizing its host, Pinus resinosa Aitman. We introduced this fungus 0, 3, 7, and 10 d before beetle entry to characterize its effects on I. pini colonization and development. This sequence allowed quantiÞcation of temporal effects and comparison of results with other systems. Fungal growth was greatest when inoculated before beetle colonization. Fungal colonization reduced beetle entry into logs, but increased brood production. Mate capture was not signiÞcantly affected by fungal growth. The beneÞts imparted by O. ips to its beetle vector during brood development are compared with results from other systems. This difference may in part be related to the exploitation of highly stressed and dead trees, rather than vigorous hosts, by I. pini.

Ophiostoma africanum sp. nov., and a key to ophiostomatoid species from Protea infructescences

Two distinct and unrelated groups of ophiostomatoid fungi are associated with Protea infructescences. Two species, Gondwanamyces proteae and G. capensis, have unique anamorphs that reside in Knoxdaviesia. This anamorph genus is infrequently found amongst species of Ceratocystis sensu lato. The second group includes Ophiostoma splendens and O. protearum that have Sporothrix anamorphs typical of Ophiostoma. During recent collections of Protea gaguedi infructescences from the Northern Province in South Africa, an apparently new species of Ophiostoma with a Sporothrix anamorph was discovered. It can be distinguished from O. splendens and O. protearum based on its short ostiolar hyphae and its associated plant host. This teleomorph is described as O. africanum and the anamorph as S. africanum. Five species of ophiostomatoid fungi are now known from Protea infructescences and a key is presented for them.