20 research outputs found
Parasitaxus parasitized: Novel infestation of Parasitaxus usta (Podocarpaceae).
The worldâs sole âparasiticâ gymnosperm Parasitaxus usta (Podocarpaceae) is endemic to the island of Grande Terre, New Caledonia. It is a threatened species because of its limited geographic range and progressing habitat fragmentation. Here, we report a novel scale insect outbreak on a Parasitaxus sub-population from Monts Dzumac in the southern part of Grande Terre. The identity of the scale insect was determined through combining morphological and molecular methods. The field collection of scale insects and their secretions from infested Parasitaxus specimens allowed morphological identification of the superfamily Coccoidea. Subsequent genetic sequencing using CO1 markers allowed phylogenetic placement of the wax scale insects to the genus Ceroplastes (Coccoidea, Coccidae), a widespread pest genus. The identified species, C. pseudoceriferus, has not been previously recorded from New Caledonia. As Parasitaxus is already vulnerable to extinction, this new threat to its long-term survival needs to be monitored. Other New Caledonian endemic plant species are potentially at risk of this new species, although it was not observed on Falcatifolium taxoides, the host of Parasitaxus.Peer reviewe
Sareomycetes cl. nov. : A new proposal for placement of the resinicolous genus Sarea (Ascomycota, Pezizomycotina)
Resinicolous fungi constitute a heterogeneous assemblage of fungi that live on fresh and solidified plant resins. The genus Sarea includes, according to current knowledge, two species, S. resinae and S. difformis. In contrast to other resinicolous discomycetes, which are placed in genera also including non-resinicolous species, Sarea species only ever fruit on resin. The taxonomic classification of Sarea has proven to be difficult and currently the genus, provisionally and based only on morphological features, has been assigned to the Trapeliales (Lecanoromycetes). In contrast, molecular studies have noted a possible affinity to the Leotiomycetes. Here we review the taxonomic placement of Sarea using sequence data from seven phylogenetically informative DNA regions including ribosomal (ITS, nucSSU, mtSSU, nucLSU) and protein-coding (rpb1, rpb2, mcm7) regions. We combined available and new sequence data with sequences from major Pezizomycotina classes, especially Lecanoromycetes and Leotiomycetes, and assembled three different taxon samplings in order to place the genus Sarea within the Pezizomycotina. Based on our data, none of the applied phylogenetic approaches (Bayesian Inference, Maximum Likelihood and Maximum Parsimony) supported the placement of Sarea in the Trapeliales or any other order in the Lecanoromycetes. A placement of Sarea within the Leotiomycetes is similarly unsupported. Based on our data, Sarea forms an isolated and highly supported phylogenetic lineage within the "Leotiomyceta". From the results of our multilocus phylogenetic analyses we propose here a new class, order, and family, Sareomycetes, Sareales and Sareaceae in the Ascomycota to accommodate the genus Sarea. The genetic variability within the newly proposed class suggests that it is a larger group that requires further infrageneric classification.Peer reviewe
Resin exudation and resinicolous communities on Araucaria humboldtensis in New Caledonia
Conifers of the endemic species Araucaria humboldtensis on Mont Humboldt in New Caledonia exhibit extensive resin exudation. The resin flows of these threatened trees are here shown to be induced by two beetle species, which bore into branches and branchlets, leading to abundant outpouring of resin, which gradually solidifies into often drop-shaped resin bodies. The exudate is colonized by a resinicolous and likely insect-vectored ascomycete, Resinogalea humboldtensis, which is only known from Mont Humboldt. The fungus grows into fresh resin and eventually develops ascomata on the surface of solidifying resin. The solidified resin is also colonized by another fungus, a dematiaceous hyphomycete. Based on protein coding (CO1, CAD, ArgK) and ribosomal (LSU) genes, the larger branch-boring beetle is a weevil of the tribe Araucariini, which represents the sister group of all other cossonine weevils. The smaller beetle species belongs to the longhorn beetles (Cerambycidae). The strong host specificity of the Araucariini, along with the occurrence of two unique fungi, suggests that the resin associated community is native and has evolved on the endemic conifer host. The formation of large amber deposits indicates massive resin production in the past, but the environmental triggers of exudation in Mesozoic and Cenozoic ecosystems remain unclear. Our observations from Mont Humboldt support the notion that the occurrences of small drop-shaped amber pieces in Triassic to Miocene amber deposits were linked to ancient insect infestations.Peer reviewe
Resinogalea humboldtensis gen. et sp. nov., a new resinicolous fungus from New Caledonia, placed in Bruceomycetaceae fam. nova (Ascomycota)
A novel species of ascomycetes is described from resin of Araucaria humboldtensis on Mont Humboldt in New Caledonia. The fungus is placed in the new genus Resinogalea Rikkinen & A.R. Schmidt, with the species name R. humboldtensis Rikkinen & A.R. Schmidt. It has only been found growing on semi-hardened resin flows on branches of its endemic and endangered conifer host. The morphology and anatomy of the new fungus are compared with those of ecologically similar taxa, including Bruceomyces castoris. The new family Bruceomycetaceae Rikkinen & A.R. Schmidt is described to accommodate Resinogalea and Bruceomyces.Peer reviewe
Stuck in time â a new Chaenothecopsis species with proliferating ascomata from Cunninghamia resin and its fossil ancestors in European amber
Resin protects wounded trees from microbial infection, but also provides a suitable substrate for the growth of highly specialized fungi. Chaenothecopsis proliferatus is described growing on resin of Cunninghamia lanceolata from Hunan Province, China. The new fungus is compared with extant species and two new fossil specimens from Eocene Baltic and Oligocene Bitterfeld ambers. The Oligocene fossil had produced proliferating ascomata identical to those of the newly described species and to other extant species of the same lineage. This morphology may represent an adaptation to growing near active resin flows: the proliferating ascomata can effectively rejuvenate if partially overrun by fresh, sticky exudate. Inward growth of fungal hyphae into resin has only been documented from Cenozoic amber fossils suggesting comparatively late occupation of resin as substrate by fungi. Still, resinicolous Chaenothecopsis species were already well adapted to their special ecological niche by the Eocene, and the morphology of these fungi has since remained remarkably constant
Chaenothecopsis schefflerae (Ascomycota: Mycocaliciales): a widespread fungus on semi-hardened exudates of endemic New Zealand Araliaceae
Ascomycetes specialised to live on hardened plant exudates occur worldwide, but the number of species so far described is relatively small (c.30). Particularly within the genus Chaenothecopsis (Ascomycota:Mycocaliciales), many species produce their ascomata on hardened but still relatively fresh outpourings of conifer resin or angiosperm exudate. Temperate rainforests of New Zealand provide habitat for several endemic Chaenothecopsis species, including Chaenothecopsis schefflerae, which was previously known from a single sample collected from the exudate of Schefflera digitata (Araliaceae) in the early 1980s. Here we show that C.schefflerae is neither lost nor very rare, but occurs sporadically throughout New Zealand. The fungus does not primarily grow on Schefflera but on exudate of several species of Pseudopanax (Araliaceae),also endemic to the region. We compare the morphology of the new specimens to the type specimen of C. schefflerae and provide a detailed description of the new material. Phylogenetic analyses based on nuclear ITS and LSU rDNA place C.schefflerae together with other morphologically similar Chaenothecopsis species growing on angiosperm exudates.Peer reviewe
Chaenothecopsis (Mycocaliciales, Ascomycota) from exudates of endemic New Zealand Podocarpaceae
The order Mycocaliciales (Ascomycota) comprises fungal species with diverse, often highly specialized substrate ecologies. Particularly within the genus Chaenothecopsis, many species exclusively occur on fresh and solidified resins or other exudates of vascular plants. In New Zealand, the only previously known species growing on plant exudate is Chaenothecopsis schefflerae, found on several endemic angiosperms in the family Araliaceae. Here we describe three new species; Chaenothecopsis matai Rikkinen, Beimforde, Tuovila & A.R. Schmidt, C. nodosa Beimforde, Tuovila, Rikkinen & A.R. Schmidt, and C. novae-zelandiae Rikkinen, Beimforde, Tuovila & A.R. Schmidt, all growing on exudates of endemic New Zealand conifers of the Podocarpaceae family, particularly on Prumnopitys taxifolia. Phylogenetic analyses based on ribosomal DNA regions (ITS and LSU) grouped them into a distinct, monophyletic clade. This, as well as the restricted host range, suggests that all three taxa are endemic to New Zealand. Copious insect frass between the ascomata contain ascospores or show an early stage of ascomata development, indicating that the fungi are spread by insects. The three new species represent the first evidence of Chaenothecopsis from any Podocarpaceae species and the first from any gymnosperm exudates in New Zealand.Peer reviewe
Estimating the Phanerozoic history of the Ascomycota lineages : Combining fossil and molecular data
Peer reviewe