| 1. |
- Cao, Bin, et al.
(författare)
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Delimiting species in Basidiomycota : a review
- 2021
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Ingår i: Fungal diversity. - : Springer Nature. - 1560-2745 .- 1878-9129. ; 109:1, s. 181-237
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Forskningsöversikt (refereegranskat)abstract
- Species delimitation is one of the most fundamental processes in biology. Biodiversity undertakings, for instance, require explicit species concepts and criteria for species delimitation in order to be relevant and translatable. However, a perfect species concept does not exist for Fungi. Here, we review the species concepts commonly used in Basidiomycota, the second largest phylum of Fungi that contains some of the best known species of mushrooms, rusts, smuts, and jelly fungi. In general, best practice is to delimitate species, publish new taxa, and conduct taxonomic revisions based on as many independent lines of evidence as possible, that is, by applying a so-called unifying (or integrative) conceptual framework. However, the types of data used vary considerably from group to group. For this reason we discuss the different classes of Basidiomycota, and for each provide: (i) a general introduction with difficulties faced in species recognition, (ii) species concepts and methods for species delimitation, and (iii) community recommendations and conclusions.
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| 2. |
- Constantinescu, Ovidiu, et al.
(författare)
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Dimorphism of sporangia in Albuginaceae (Chromista, Peronosporomycetes)
- 2006
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Ingår i: Sydowia. - 0082-0598. ; 58:2, s. 178-190
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Tidskriftsartikel (refereegranskat)abstract
- By using light- and scanning electron microscopy, the dimorphism of sporangia in Albuginales is demonstrated in 220 specimens of Albugo, Pustula and Wilsoniana, parasitic on plants belonging to 13 families. The presence of two kinds of sporangia is due to the sporangiogenesis and considered to be present in all representatives of the Albuginales. Primary and secondary sporangia are the term recommended to be used for these dissemination organs.
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| 3. |
- Constantinescu, Ovidiu, et al.
(författare)
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Plasmopara halstedii is absent from Australia and New Zealand
- 2010
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Ingår i: Polish Botanical Journal. ; 55:2, s. 293-298
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Tidskriftsartikel (refereegranskat)abstract
- Plasmopara halstedii (Farl.) Berl. & de Toni is among the most important species hampering commercial sunfl owerproduction in many countries. Downy mildew on Arctotheca and Arctotis collected in Australia and New Zealand has been attributedto Plasmopara halstedii, although it has never been reported on sunfl ower in those two countries. Potentially this makesit diffi cult for Australia and New Zealand to claim to be free of sunfl ower downy mildew; this has implications for quarantineand trade. Here we present morphological and molecular analyses of specimens of Plasmopara on Arctotis and Arctotheca collectedin Australia and New Zealand. Our results demonstrate that these plants are not attacked by Plasmopara halstedii but bya new species which we formally describe as Plasmopara majewskii sp. nov. in this study. Consequently, quarantine regulationsfor P. halstedii need to be enforced in order to protect the commercial sunfl ower industry in Australia and New Zealand.
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| 4. |
- Haas, Brian J., et al.
(författare)
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Genome sequence and analysis of the Irish potato famine pathogen Phytophthora infestans
- 2009
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Ingår i: Nature. - : Springer Science and Business Media LLC. - 0028-0836 .- 1476-4687. ; 461:7262, s. 393-398
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Tidskriftsartikel (refereegranskat)abstract
- Phytophthora infestans is the most destructive pathogen of potato and a model organism for the oomycetes, a distinct lineage of fungus-like eukaryotes that are related to organisms such as brown algae and diatoms. As the agent of the Irish potato famine in the mid-nineteenth century, P. infestans has had a tremendous effect on human history, resulting in famine and population displacement(1). To this day, it affects world agriculture by causing the most destructive disease of potato, the fourth largest food crop and a critical alternative to the major cereal crops for feeding the world's population(1). Current annual worldwide potato crop losses due to late blight are conservatively estimated at $6.7 billion(2). Management of this devastating pathogen is challenged by its remarkable speed of adaptation to control strategies such as genetically resistant cultivars(3,4). Here we report the sequence of the P. infestans genome, which at similar to 240 megabases (Mb) is by far the largest and most complex genome sequenced so far in the chromalveolates. Its expansion results from a proliferation of repetitive DNA accounting for similar to 74% of the genome. Comparison with two other Phytophthora genomes showed rapid turnover and extensive expansion of specific families of secreted disease effector proteins, including many genes that are induced during infection or are predicted to have activities that alter host physiology. These fast-evolving effector genes are localized to highly dynamic and expanded regions of the P. infestans genome. This probably plays a crucial part in the rapid adaptability of the pathogen to host plants and underpins its evolutionary potential.
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| 5. |
- Zamora, Juan Carlos, et al.
(författare)
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Considerations and consequences of allowing DNA sequence data as types of fungal taxa
- 2018
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Ingår i: IMA Fungus. - : INT MYCOLOGICAL ASSOC. - 2210-6340 .- 2210-6359. ; 9:1, s. 167-185
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Tidskriftsartikel (refereegranskat)abstract
- Nomenclatural type definitions are one of the most important concepts in biological nomenclature. Being physical objects that can be re-studied by other researchers, types permanently link taxonomy (an artificial agreement to classify biological diversity) with nomenclature (an artificial agreement to name biological diversity). Two proposals to amend the International Code of Nomenclature for algae, fungi, and plants (ICN), allowing DNA sequences alone (of any region and extent) to serve as types of taxon names for voucherless fungi (mainly putative taxa from environmental DNA sequences), have been submitted to be voted on at the 11th International Mycological Congress (Puerto Rico, July 2018). We consider various genetic processes affecting the distribution of alleles among taxa and find that alleles may not consistently and uniquely represent the species within which they are contained. Should the proposals be accepted, the meaning of nomenclatural types would change in a fundamental way from physical objects as sources of data to the data themselves. Such changes are conducive to irreproducible science, the potential typification on artefactual data, and massive creation of names with low information content, ultimately causing nomenclatural instability and unnecessary work for future researchers that would stall future explorations of fungal diversity. We conclude that the acceptance of DNA sequences alone as types of names of taxa, under the terms used in the current proposals, is unnecessary and would not solve the problem of naming putative taxa known only from DNA sequences in a scientifically defensible way. As an alternative, we highlight the use of formulas for naming putative taxa (candidate taxa) that do not require any modification of the ICN.
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