Literatura Reciente sobre Briofitas

Riella heliospora (Riellaceae) a New Monoicous Species of Riella Subgenus Trabutiella from California

2012-05-08T02:22:19Z

Taxonomy and Phylogeny of Andina (Pottiaceae, Bryophyta): a New Moss Genus from the Tropical Andes

2012-05-08T02:21:49Z

New book: Rare and threatened bryophytes of Ireland

2012-05-03T15:29:00Z

Dear bryologists, I’d like to publicise one of the best bryophyte books I have seen in recent years – Rare and threatened bryophytes of Ireland, by Neil Lockhart, Nick Hodgetts and David Holyoak. I think it is the most superb Red-data book I have seen. It is wonderfully illustrated with bryophyte portraits by some first class photographers, and the habitat pictures are truly stunning. If you google it you can get a link to purchase it online. It should give a another boost to bryophyte conservation and study in Ireland, which has been really flourishing over the last few years.
David Long

Dr David G. Long
Head of Cryptogamic Plants & Fungi Section
Royal Botanic Garden
Edinburgh EH3 5LR
UK

Evolution of the life cycle in land plants

2012-05-14T17:01:51Z

Abstract All sexually reproducing eukaryotes have a life cycle consisting of a haploid and a diploid phase, marked by meiosis and syngamy (fertilization). Each phase is adapted to certain environmental conditions. In land plants, the recently reconstructed phylogeny indicates that the life cycle has evolved from a condition with a dominant free-living haploid gametophyte to one with a dominant free-living diploid sporophyte. The latter condition allows plants to produce more genotypic diversity by harnessing the diversity-generating power of meiosis and fertilization, and is selectively favored as more solar energy is fixed and fed into the biosystem on earth and the environment becomes more heterogeneous entropically. Liverworts occupy an important position for understanding the origin of the diploid generation in the life cycle of land plants. Hornworts and lycophytes represent critical extant transitional groups in the change from the gametophyte to the sporophyte as the independent free-living generation. Seed plants, with the most elaborate sporophyte and the most reduced gametophyte (except the megagametophyte in many gymnosperms), have the best developed sexual reproduction system that can be matched only by mammals among eukaryotes: an ancient and stable sex determination mechanism (heterospory) that enhances outcrossing, a highly bimodal and skewed distribution of sperm and egg numbers, a male-driven mutation system, female specialization in mutation selection and nourishment of the offspring, and well developed internal fertilization. The study of evolution of the land plant life cycle requires a multidisciplinary approach that considers morphology, development, genetics, phylogeny, ecology, and evolution in an integrated fashion, and will deepen our understanding of plant evolution.

Contribution to the bryological flora of Argentina. Sphagnum perichaetiale Hampe. and S. recurvum P. Beauv. (Sphagnaceae)

2012-04-24T19:28:13Z

The Bryologist, Volume 115, Issue 1, Page 178-182, Spring 2012.

ITS and morphology tell different histories about the species of the Sciuro-hypnum reflexum complex (Brachytheciaceae, Bryophyta)

2012-04-24T19:28:33Z

The Bryologist, Volume 115, Issue 1, Page 153-172, Spring 2012.

A phylogenetic monograph of the Sphagnum subsecundum complex (Sphagnaceae) in eastern North America

2012-04-24T19:28:10Z

The Bryologist, Volume 115, Issue 1, Page 128-152, Spring 2012.

Edaphic and phytosociological factors influencing moss species occurrence in a northern hardwood forest

2012-04-24T19:28:24Z

The Bryologist, Volume 115, Issue 1, Page 118-127, Spring 2012.

A re-interpretation of the Fabroniaceae, a phylogenetic perspective

2012-04-24T19:27:49Z

The Bryologist, Volume 115, Issue 1, Page 109-117, Spring 2012.

Morphological and molecular differentiation of Aerobryopsis eravikulamensis Manju & Rajesh sp. nov. (Meteoriaceae) and closely related taxa of the Western Ghats of India

2012-04-24T19:28:23Z

The Bryologist, Volume 115, Issue 1, Page 42-50, Spring 2012.

Climacium (Climaciaceae): species relationships and biogeographic implications

2012-04-24T19:28:15Z

The Bryologist, Volume 115, Issue 1, Page 23-30, Spring 2012.

The potential distribution of Grimmia (Grimmiaceae) in Mexico

2012-04-24T19:28:06Z

The Bryologist, Volume 115, Issue 1, Page 12-22, Spring 2012.

Invited perspective: bryophytes as models for understanding the evolution of sexual systems

2012-04-24T19:28:03Z

The Bryologist, Volume 115, Issue 1, Page 1-11, Spring 2012.

Extended Periods of Hydration Do Not Elicit Dehardening to Desiccation Tolerance in Regeneration Trials of the Moss Syntrichia caninervis

2012-04-17T19:49:52Z

International Journal of Plant Sciences, Volume 173, Issue 4, Page 333-343, May 2012.

The rare peat moss Sphagnum wulfianum (Sphagnaceae) did not survive the last glacial period in northern European refugia [Evolution and Phylogeny]

2012-04-09T05:32:15Z

• Premise of the study: Organisms may survive unfavorable conditions either by moving to more favorable areas by means of dispersal or by adapting to stressful environments. Pleistocene glacial periods represent extremely unfavorable conditions for the majority of life forms, especially sessile organisms. Many studies have revealed placements of refugial areas and postglacial colonization patterns of seed plants, but little is still known about areas of long-term survival and historical migration routes of bryophytes. Given overall differences in stress tolerance between seed plants and bryophytes, it is of interest to know whether bryophytes have survived periods of extreme climatic conditions better then seed plants in northern areas.

• Methods: The haploid and rarely spore-producing peat moss Sphagnum wulfianum is mostly found in areas that were covered by ice during the last glacial maximum. Twelve microsatellite markers were amplified from 43 populations (367 shoots) of this species, and data were analyzed using population genetic diversity statistics, Bayesian clustering methods, and coalescence-based inference tools to estimate historical and demographic parameters.

• Key results: Genetic diversity within populations was low, but populations were highly differentiated, with two main genetic clusters being recognized.

• Conclusion: The two main genetic groups have diverged quite recently in the Holocene, and the pattern of genetic variability and structuring gives no support for survival in Scandinavian refugia during the last glacial period in this species. The dispersal ability of this plant thus seems surprisingly high despite its infrequent spore production.

Genetic analysis of the peatmoss iSphagnum cribrosum/i (Sphagnaceae) indicates independent origins of an extreme infra-specific morphology shift

2012-04-09T20:37:42Z

Major transitions in the evolution of early land plants: a bryological perspective

2012-04-04T01:03:58Z

Tolerance to environmental desiccation in moss sperm

2012-05-01T05:00:00Z

Summary

•
Sexual reproduction in mosses requires that sperm be released freely into the environment before finding and fertilizing a receptive female. After release from the male plant, moss sperm may experience a range of abiotic stresses; however, few data are available examining stress tolerance of moss sperm and whether there is genetic variation for stress tolerance in this important life stage.
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Here, we investigated the effects of environmental desiccation and recovery on the sperm cells of three moss species (Bryum argenteum, Campylopus introflexus, and Ceratodon purpureus).
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We found that a fraction of sperm cells were tolerant to environmental desiccation for extended periods (d) and that tolerance did not vary among species. We found that this tolerance occurs irrespective of ambient dehydration conditions, and that the addition of sucrose during dry-down improved cell recovery. Although we observed no interspecific variation, significant variation among individuals within species in sperm cell tolerance to environmental desiccation was observed, suggesting selection could potentially act on this basic reproductive trait.
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The observation of desiccation-tolerant sperm in multiple moss species has important implications for understanding bryophyte reproduction, suggesting the presence of a significant, uncharacterized complexity in the ecology of moss mating systems.

Membrane stability of the desert moss Syntrichia caninervis Mitt. during desiccation and rehydration

2012-03-13T16:09:57Z

Differences in spatial genetic structure and diversity in two mosses with different dispersal strategies in a fragmented landscape

2012-03-13T16:09:45Z