References of "Ignatov, Michael"
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See detailFurther taxonomic rearrangements in the Brachytheciaceae (Bryophyta): Frahmiella, a new genus segregated from Rhynchostegiella
Ignatov, Michael; Aigoin, Delphine ULg; Huttunen, Sanna et al

in Tropical Bryology (2010), 31

The taxonomic position of Rhynchostegiella acicula, a local endemic of Shaanxi Province of China, is investigated by means of cladistic analyses employing nrITS sequences. The analyses show that R ... [more ▼]

The taxonomic position of Rhynchostegiella acicula, a local endemic of Shaanxi Province of China, is investigated by means of cladistic analyses employing nrITS sequences. The analyses show that R. acicula does not belong to Rhynchostegiella s.str. (Helicodontioideae) but is resolved within the Homalothecioideae as sister to Eurhynchiastrum, from which it differs by a soft and slender habit; narrow lanceolate and acuminate leaves; a percurrent costa; and an autoicous condition. It differs from Brachytheciastrum and Brachythecium in a longly rostrate operculum, and from Homalothecium in a small plants that lack thick-walled basal laminal cells characteristic of this genus, as well as in an autoicous inflorescence. As a consequence, R. acicula is transferred into its own, monospecific genus Frahmiella Ignatov, Vanderpoorten & Wang You-fang, gen. nov. [less ▲]

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See detailRhynchostegiella (Brachytheciaceae): molecular re-circumscription of a convenient taxonomic repository
Aigoin, Delphine ULg; Huttunen, Sanna; Ignatov, Michael et al

in Journal of Bryology (2009), 31

The moss genus Rhynchostegiella (Helicodontioideae, Brachytheciaceae) has long served as a convenient repository for small brachythecioid pleurocarps. Its circumscription is revised in the context of a ... [more ▼]

The moss genus Rhynchostegiella (Helicodontioideae, Brachytheciaceae) has long served as a convenient repository for small brachythecioid pleurocarps. Its circumscription is revised in the context of a chloroplast phylogeny of the Helicodontioideae employing trnL-trnF, atpB-rbcL, psbT-psbH, and psbA-trnH sequence data. The analysis resolves with full posterior probabilities a core Rhynchostegiella clade of eight species. Rhynchostegiella pumila and R. duriaei are both resolved outside that clade and accommodated in their own genera, Microeurhynchium gen. nov. and Pseudorhynchostegiella gen. nov., respectively. Rhynchostegiella leptoneura is sister to Aerolindigia capillacea and R. papuensis is closely related to Eurhynchiella zeyheri. One of the reasons why these unrelated species, together with other taxa, were traditionally included within Rhynchostegiella, is that the genus is morphologically poorly defined by only a single synapomorphic change followed by reversals in half of the species. The Madeiran endemic Brachythecium percurrens is resolved as sister to all the other genera of the Helicodontioideae and is transferred into a new monotypic genus, Hedenasiastrum gen. nov. [less ▲]

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See detailAnd if Engler was not completely wrong? Evidence for multiple evolutionary origins in the moss flora Of Macaronesia
Aigoin, Delphine ULg; Devos, Nicolas ULg; Huttunen, Sanna et al

in Evolution (2009), 63(12), 32483257

The Macaronesian endemic flora has traditionally been interpreted as a relict of a subtropical element that spanned across Europe in the Tertiary. This hypothesis is revisited in the moss subfamily ... [more ▼]

The Macaronesian endemic flora has traditionally been interpreted as a relict of a subtropical element that spanned across Europe in the Tertiary. This hypothesis is revisited in the moss subfamily Helicodontioideae based on molecular divergence estimates derived from two independent calibration techniques either employing fossil evidence or using an Monte Carlo Markov Chain (MCMC) to sample absolute rates of nucleotide substitution from a prior distribution encompassing a wide range of rates documented across land plants. Both analyses suggest that the monotypic Madeiran endemic genus Hedenasiastrum diverged of other Helicodontioideae about 40 million years, that is, well before Macaronesian archipelagos actually emerged, in agreement with the relict hypothesis. Hedenasiastrum is characterized by a plesiomorphic morphology, which is suggestive of a complete morphological stasis over 40 million years. Macaronesian endemic Rhynchostegiella species, whose polyphyletic origin involves multiple colonization events, evolved much more recently, and yet accumulated many more morphological novelties than H. percurrens. The Macaronesian moss flora thus appears as a complex mix of ancient relicts and more recently dispersed, fast-evolving taxa. [less ▲]

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