The Hepaticae of western North America, in contrast to eastern North America and many other parts of the world, are poorly known. This present flora for southwestern British Columbia, Canada, and part of northwestern Washington State, U.S.A., is intended to partially alleviate this problem. The geographical area covered in this study offers great diversity in topography, climate, and vegetation. The region includes the wet Pacific coast of western Vancouver Island, mesic forests and floodplains of low elevations, the dry area around southern Georgia Strait, subalpine forests and meadows of the Coast Range and North Cascade Mountains, alpine soil and rock substrates at highest elevations below summer snowline or glaciers, and dry habitats in the rainshadow northeast of the mountains. The material presented is based on direct study of approximately 4000 personal and 1800 herbarium collections of hepatics. A total of 166 species and two additional varieties, belonging to 64 genera in 37 families, are treated in keys and concise descriptions, accompanied by ecological and phytogeographical information. Additional discussion on taxonomic and systematic difficulties is given where pertinent. Five hepatics new to science were discovered during this study, with Schofieldia monticola Godfr. having been recently described. Hepatics collected which had not been reported previously from continental North America include Eremonotus myriocarpus (Carring.) Lindb. et Pears, in Pears., Jungermannia hattoriana (Amak.) Amak., Marsupella condensata (Ångstr. in Hartm.) Schiffn., and Nardia japonica Steph. Hepatics belonging to, or similar to, Lophozia elongata Steph. and Marsupella adusta (Nees emend. Limpr.) Spruce were collected. Hepatics new to British Columbia include Lophozia ventricosa var. silvicola (Buch) Jones, Riccia frostii Aust., Scapania gymnostomophila Kaal., and S. paludlcola Loeske et K. Müll, in K. Müll. For the first time, fasciculate gemmae were discovered in Ghandonanthus Mitt., and inflated lobules were found in Porella navicularis (Lehm. et Lindenb.) Lindb. Based on specimens exajnined from the study area, Bazzania ambigua (Lindenb.) Trev., Odontoschisma gibbsiae Evans, and Plagiochlla satoi Hatt. were treated as synonyms of other species in this flora. Systematic problems requiring detailed future study were encountered in particular in Bazzania S. Gray and Galypogeia Raddi emend. Nees. Regional distribution-maps depicting all known points of occurrence and general elevation are presented for all hepatics discussed in this flora. Four general categories of distribution were demonstrated by a comparison of the spatial patterns: l) distributions in moist, humid climates influenced to varying degrees by the Pacific Ocean (18% of the total flora), 2) high elevations in the Coast and Cascade Mountains (24%), 3) dry climates in rainshadow areas (16%), and 4) various types of widespread distributions (33%). The remaining 9% of the species are rare or infrequent and cannot be assigned to any particular category. The hepatic taxa were assigned to 14 phytogeographical elements based on total worldwide distributions. Approximately 50% of the hepatics have essentially circumboreal distributions. This figure includes taxa missing from eastern Asia. Ten percent of the hepatics are endemic to western North America. Of the hepatics demonstrating disjunct, or discontinuous distributions, 16% have European affinities, 9% eastern Asian affinities, and 11%, affinities with both regions. Approximately 11% of the hepatics treated in this flora have bipolar disjunctions. In an attempt to reconstruct some events in the development of the modem hepatic flora of southwestern British Columbia, possible Pleistocene refugia and their effect on hepatic populations are discussed. This flora will provide a manual for the Hepaticae and Anthocerotae of southwestern British Columbia, and will serve as a preliminary guide to these plants in the North American Pacific Northwest. / Science, Faculty of / Botany, Department of / Graduate

Thesis (M.S.)--University of Akron, Dept. of Biology, 2006. / "December, 2006." Title from electronic thesis title page (viewed 12/31/2008) Advisor, Robert Joel Duff; Committee members, Richard Londraville, Francisco B. Moore, Amy Milsted; Department Chair, Bruce Cushing; Dean of the College, Ronald F. Levant; Dean of the Graduate School, George R. Newkome. Includes bibliographical references.

Spores are fundamental to the reproductive success of all land plants. The success of a spore lies in its recalcitrant multi-layered spore wall commonly made of sporopollenin, cellulose, and pectin. However, other polysaccharides may be associated with the intine of spores, and their patterns of deposition vary across taxa. Callose, a plant 1-3-β-glucan polysaccharide, has unsubstantiated accounts of its presence and absence in association with the spore mother cell wall of hornworts for more than a century. To address this conundrum, I used aniline blue, a fluorochrome that has high specificity of binding to beta glucans and when excited with ultraviolet light, it will fluoresce yellow-green. However, due to the limited resolution power of that technique, I also used transmission electron microscopy (TEM) with immunogold labeling to observe the ultrastructural localization of callose using anticallose, a monoclonal antibody. I also bioinformatically probed the genomes and transcriptomes of hornworts to elucidate the callose synthase genes and enzymes which may be responsible for the putative callose deposition. Because of the asynchronous spore development, each sporophyte has a continuum of spores at various developmental stages. Subsequently, the sporophyte of many hornworts makes an ideal system to study all aspects of sporogenesis. For the first time, I provide unequivocal, correlative evidence for callose involvement in spore wall development in hornworts. Here we report on the spatiotemporal deposition of callose in sporogenesis of Phaeoceros carolinianus, and we show that callose is a common wall constituent of the spore intine in three other genera (Anthoceros, Notothylas, and Nothoceros). Callose deposition in hornworts is post-meiotic and begins during early spore wall development after a white lined lemella is formed and during expansion of the exine. As sporopollenin is deposited and the spore wall thickens, callose remains localized in the intine during the remainder of sporogenesis. The occurrence of callose in hornwort spores is a first record of this polysaccharide in the inner spore wall (intine or endospore) of any embryophyte. This suggests that callose may serve the same or similar roles in hornwort intine development and function as pectin-cellulose does in later diverging taxa. Bioinformatic tblastn techniques and molecular high through put Illumina genome sequencing combined with blast techniques for orthologs to callose synthase genes from Arabidopsis thaliana and Physcomitrella patens did not provide any evidence as to if callose synthase genes are present in hornworts This was due to database contamination, sample contamination, and sample quality.

No description available.

<p>Plants use an array of photoreceptors to measure the quality, quantity, and direction of light in order to respond to ever-changing light environments. Photoreceptors not only determine how and when individual plants complete their life cycles, but they also have a profound and long-term macroevolutionary influence on species diversification. Despite their significances, very little is known about photoreceptors across plants as whole, and we lack a comprehensive view of photoreceptor evolution. </p><p> In my dissertation, I investigate the origin and evolution of three of the most prominent photoreceptor gene families in plants: phytochromes, phototropins and neochromes. Using newly available transcriptomic and genomic data, I completed the first in-depth survey of these photoreceptor families across land plants, green algae, red algae, glaucophytes, cryptophytes, haptophytes, and stramenopiles. </p><p> Phytochromes are red/far-red photoreceptors that play essential roles in seed germination, seedling photomorphogenesis, shade-avoidance, dormancy, circadian rhythm, phototropism, and flowering. Here, I show that the canonical plant phytochromes originated in a common ancestor of streptophytes (charophyte green algae plus land plants), and I identify the most likely sequence whereby the plant phytochrome structure evolved from its ancestral phytochrome. Phytochromes in charophyte algae are structurally diverse, including canonical and non-canonical forms, whereas in land plants, phytochrome structure is highly conserved. Liverworts, hornworts, and Selaginella apparently possess a single phytochrome gene copy, whereas independent gene duplications occurred within mosses, lycopods, ferns, and seed plants, leading to diverse phytochrome families in these clades. My detailed phylogeny encompasses all of green plants and enables me to not only uncover new phytochrome lineages, but also to make links to our current understanding of phytochrome function in Arabidopsis and Physcomitrella (the major model organism outside of flowering plants). Based on this robust evolutionary framework, I propose new hypotheses and discuss future directions to study phytochrome mechanisms.</p><p> Phototropins are blue-light photoreceptors that regulate key adaptive physiological responses, including shoot-positive phototropism, root-negative phototropism, chloroplast accumulation/avoidance, stomatal opening, circadian rhythm, leaf expansion, and seedling elongation I show that phototropins originated in the common ancestor of Viridiplantae (all green algae [charophytes, chlorophytes, prasinophytes] plus land plants). Phototropins repeatedly underwent independent duplications in all major plant lineages (mosses, lycopods, ferns and seed plants), except for liverworts and hornworts, where phototropin is a single-copy gene. Following each major duplication event, phototropins subsequently differentiated in parallel, resulting in two specialized (yet partially overlapping) functional forms that primarily mediate either low- or high-light responses. My gene phylogeny further suggests that phototropins have co-evolved with phytochromes, as is evident from their molecular interactions and strikingly similar gene duplication patterns. I hypothesize that the co-evolution of phototropins with phytochromes, together with their subsequent convergent functional divergences in phototropic responses, contributed to the success of plants in adapting to diverse and heterogeneous habitats.</p><p> Neochromes are chimeric photoreceptors that, by fusing phytochrome and phototropin modules into a single protein, are able to use both red/far-red and blue light to modulate phototropic responses. Neochromes were first discovered in ferns, and the evolution of neochromes was implicated as a key innovation that facilitated fern diversification under the low-light angiosperm canopies. Despite its significance from an evolutionary standpoint, the origin of neochromes has remained a mystery. Here I present the first evidence for neochrome in hornworts (a bryophyte lineage) and demonstrate that ferns acquired neochrome from hornworts via horizontal gene transfer (HGT). Fern neochromes are nested within hornwort neochromes in my large-scale phylogenetic reconstructions of phototropin and phytochrome gene families. Divergence date estimates further support the HGT hypothesis, with fern and hornwort neochromes diverging 179 MYA, long after the split between the two plant lineages (at least 400 MYA). By analyzing the draft genome of the Anthoceros punctatus hornwort, I also discovered a novel phototropin gene that likely represents the ancestral lineage of the neochrome phototropin module. Thus, a neochrome originating in hornworts was horizontally transferred to ferns, where it may have played a significant role in the diversification of modern ferns. </p><p> In summary, my studies identified the molecular origins of phytochromes, phototropins and neochromes, and reconstructed their respective evolutionary histories. This new framework for photoreceptor evolution will stimulate new research linking ecology, evolution, and photochemistry to understand how plants adapt to variable light environments.</p> / Dissertation

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-04-27T14:19:35Z No. of bitstreams: 1 tatianasilvasiviero.pdf: 4161526 bytes, checksum: aa313690034029200390bdb41f7e79ae (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-05-02T01:00:55Z (GMT) No. of bitstreams: 1 tatianasilvasiviero.pdf: 4161526 bytes, checksum: aa313690034029200390bdb41f7e79ae (MD5) / Made available in DSpace on 2016-05-02T01:00:55Z (GMT). No. of bitstreams: 1 tatianasilvasiviero.pdf: 4161526 bytes, checksum: aa313690034029200390bdb41f7e79ae (MD5) Previous issue date: 2015-08-14 / Briófitas são plantas terrestres, criptogâmicas, representadas por três unidades monofiléticas: hepáticas, antóceros e musgos. São cosmopolitas, entretanto, devido à dependência de água para reprodução e crescimento vegetativo, são mais frequentes em áreas úmidas, como florestas tropicais, sendo muito representativas em áreas do Domínio da Floresta Atlântica, no Brasil. O Parque Estadual do Ibitipoca está inserido no Domínio da Floresta Atlântica, no estado de Minas Gerais, e é composto por diferentes fitofisionomias florestais, campestres, arbustivas e savânicas. O objetivo do presente trabalho foi estudar a ecologia de briófitas no Parque Estadual do Ibitipoca. As plantas foram amostradas seguindo-se dois métodos de coleta: caminhamento e parcelas. Foram avaliadas características das associações de briófitas ao longo de diferentes fitofisionomias do Parque, para verificar se há competição entre as plantas estudadas; foram analisadas as estruturas das comunidades de musgos da borda e interior da fitofisionomia Floresta Latifoliada Nebular Perenifólia Tropical Superomontana, a fim de avaliar se há diferença entre essas comunidades; e foram comparados os resultados obtidos através dos dois métodos de coleta, a fim de determinar o melhor método para estudo de briófitas em área florestal. No total, foram analisados 2785 espécimes de briófitas, identificadas em 246 espécies. 31 espécies de briófitas foram citadas pela primeira vez para o Parque Estadual do Ibitipoca, sendo 22 espécies de hepáticas e nove espécies de musgos. Três dessas espécies são endêmicas para o Brasil. Aproximadamente 75% das espécies avaliadas foram coletadas em associação, nas diferentes fitofisionomias do Parque; o elevado número de briófitas moderadamente e muito associáveis em florestas úmidas, aliado a análises de modelos nulos de co-ocorrência de espécies sugeriram que não há competição por umidade entre as associações de briófitas do Parque Estadual do Ibitipoca. Foi observada diferença entre a estrutura de comunidades de briófitas da borda e do interior da Floresta Latifoliada Nebular Perenifólia Tropical Superomontana do Parque. A comparação entre o método de coleta do caminhamento e de parcelas, para a Floresta Nebular indicou diferenças nos resultados entre os métodos. Foi necessário menor esforço de coleta de briófitas para o método de parcelas do que para o método do caminhamento. Entretanto, a relação entre o número de espécies de briófitas identificadas e o número de espécimes coletados foi maior quando se utilizou o método do caminhamento, se comparado ao método de parcelas. / Bryophytes are terrestrial and cryptogamic plants. They are represented by three monophyletic units: liverworts, hornworts and mosses. They are cosmopolitan, however, due to dependence on water for reproduction and vegetative growth, they are more common in moist areas, such as tropical forests. They are very representative at Brazilian Atlantic Forest Domain, in Brazil. Parque Estadual do Ibitipoca is situated at Atlantic Forest Domain, at Minas Gerais state. It encompasses different forest, grassland, shrub and savanna phytophysiognomies. The aim of this work was to study bryophyte’s ecology at Parque Estadual do Ibitipoca. The plants were collected following two collecting methods: free walking and plots. We evaluated characteristics from bryophytes associations in different phytophysiognomies at Parque, to check if there is competition between studied plants; we analyzed mosses communities structures from the edge to interior of the phytophysiogomy: Floresta Latifoliada Nebular Perenifólia Tropical Superomontana, to evaluate if there is difference between these mosses’ communities; and we compared the results obtained between the two collecting methods, to determine which is the best method to study bryophytes at forest areas. We analyzed 2785 bryophytes specimens, identified into 246 species. 31 bryophytes species were cited for the first time to Parque Estadual do Ibtipoca, 22 are liverworts species and nine are mosses species. Three species are endemic from Brazil. Almost 75% of the species analyzed were collected in association, at different phytophysiognomies from the Parque; the high number of bryophytes moderately associable and very associable found at humid areas, allied to null models of species co-occurrence patterns suggested that bryophytes from Parque Estadual do Ibitipoca are not competing by humidity. We observed differences between bryophyte’s communities structure at edge and interior from Floresta Latifoliada Nebular Perenifólia Tropical Superomontana. Comparisons between free walking and plots methods showed different results between these methods. It was necessary less collection effort to plots method than free walking method. However, the relation between number of bryophyte’s species identified and number of specimens collected were larger when we utilized free walking method, if comparing with plots method.

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No. of bitstreams: 1 prisciladesouzamachado.pdf: 2000346 bytes, checksum: 31d0609b0e70ce2dec7cdd6117b55ccd (MD5) Previous issue date: 2011-03-31 / FAPEMIG - Fundação de Amparo à Pesquisa do Estado de Minas Gerais / As briófitas são plantas criptogâmicas, caracterizam-se por uma estrutura simples, devido à ausência de sistema vascular e lignina, possuem pequeno porte e apresentam um ciclo de vida único entre as plantas terrestres, com dominância do gametófito - que é haplóide, clorofilado folhoso ou taloso - e, esporófito - diplóide, é efêmero e dependente do gametófito. O estudo de briófitas urbanas é importante para gerar conhecimento sobre distribuição geográfica, espécies tolerantes à ocupação humana, utilização de briófitas como bioindicadoras da qualidade do ar e criação da cultura de preservação da biodiversidade urbana. No Brasil, ainda há poucos trabalhos. Assim, este estudo teve por objetivos levantar a brioflora do município de Juiz de Fora (MG), relacionar as espécies encontradas com os substratos em que as mesmas ocorrem, comparar os resultados obtidos com outros estudos desenvolvidos sobre briófitas urbanas do Brasil e, incrementar o conhecimento da brioflora do estado de Minas Gerais. Foram realizadas coletas em três pontos selecionados no município (Campus da Universidade Federal de Juiz de Fora (UFJF), Parque Halfeld e Parque Municipal da Lajinha), considerando-se fragmentos florestais e áreas com interferência antrópica. As briófitas foram coletadas de forma aleatória, manualmente ou com auxílio de uma espátula, acondicionadas em sacos de papel, e levadas ao Laboratório de Briófitas da UFJF para secagem à temperatura ambiente e posterior identificação. Para a identificação, foram empregadas a literatura especializada e a comparação com exsicatas previamente identificadas por especialistas. Foram analisados 773 espécimes de briófitas em um total de 128 espécies, 83 gêneros, 45 famílias e 19 ordens, assim distribuídas: antóceros (sete espécimes, em três espécies, três gêneros, duas famílias e uma ordem); hepáticas (238 espécimes, em 44 espécies, 26 gêneros, 16 famílias e sete ordens) e musgos (528 espécimes, em 81 espécies, 54 gêneros, 27 famílias e 11 ordens). As famílias mais representativas foram Lejeuneaceae e Frullaniaceae para as hepáticas, Bryaceae e Pottiaceae para os musgos. Foram encontrados 27 novos registros de espécies para o estado de Minas Gerais. Analisando-se os substratos em que as plantas foram encontradas, tronco vivo foi o mais frequente, seguido de solo, tronco morto, rocha, artificial e folha. No Parque Halfeld, foram coletados 64 espécimes identificados em 16 espécies; no Campus da UFJF, foram 336 espécimes, perfazendo um total de 85 espécies e, no Parque Municipal da Lajinha, foram coletados 373 espécimes, consistindo em 81 espécies. / The bryophytes are cryptogamic plants having a simple structure due to the absence of vascular system and lignin, they commonly present a small size and a single life cycle among the terrestrial plants, with the dominance of the gametophytic generation, which is haploid, thallose or foliose with clorophyll; the sporophytic generation is ephemeral, diploid and dependent on the gametophyte. The study of urban bryophyte is important to analyse: the geographical distribution; species that are tolerant to human occupation; the use of bryophytes as bioindicators of air quality and to create a culture of urban biodiversity preservation. In Brazil, there are few studies. Thus this study aimed to identify and describe the bryophytes that exist in Juiz de Fora (MG), besides of analyzing the relationship among species and the substrate they are found, comparing these results to other data about Brazilian urban bryophytes and increasing the knowledge of bryophytes in Minas Gerais state. The bryophytes were collected between September of 2009 and August of 2010 in three places of the city (Juiz de Fora Federal University campus-UFJF;Halfeld Park and Municipal Lajinha Park), considering forestal fragments and areas having human interference. They were randomly and manually withdrawn or with the aid of a spatula, placed in paper bags and taken to the Laboratory of Bryophytes (UFJF) to be dried out on environment temperature and identified using specialized literature. We analyzed 773 specimens of bryophytes in a total of 128 species, 80 genera, 45 families and 19 orders, distributed in three groups: hornworts (seven specimens in three species, three genera, two families and one order), liverworts (238 specimens in 44 species, 25 genera, 16 families and seven orders) and mosses (528 specimens in 81 species, 54 genera, 27 families and 11 orders). The most representative families of liverworts were Lejeuneaceae and Frullaniaceae and for mosses were Bryaceae and Pottiaceae. We found 27 new registers of bryophytes species for the state of Minas Gerais. Concerning to the substrates where the plants were found, living trunk was the most representative, followed by soil, dead trunk, rock, artificial substrate and leaf. In Halfeld Park, we collected 64 specimens in 16 species; in UFJF Campus, 336 specimens were identified in 85 species and in Lajinha Park, 373 specimens were identified in 81 species.