Sökning: "sporophytes"

Hittade 5 avhandlingar innehållade ordet sporophytes.

  1. 1. Genetic variation and sexual reproduction in a moss with dwarf males, Homalothecium lutescens

    Författare :Frida Rosengren; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; bryophytes; mosses; dwarf males; sexual reproduction; genetic variation; genetic structure; inbreeding; isozymes; allozymes; SNP; sporophytes; spore; fertilization; fertility;

    Sammanfattning : Dwarf males occur in many unrelated groups of organisms. Among land plants they are unique to mosses. Moss dwarf males originate from male spores that land and germinate on the female where their final size is restricted to a few mm. Fertilization in mosses occur over short distances with swimming spermatozoids. LÄS MER

  3. 2. Gene transfer by interspecific hybridization in bryophytes

    Författare :Weerachon Sawangproh; Biodiversitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; homozygote; heterozygote; admixture; single nucleotide polymorphism; STRUCTURE; PCoA; hybrid index; inbreeding; outbreeding; hybrid depression; heterosis; phylogeny; purging selection; genetic purging; genotype; phenotype; sympatry; allopatry;

    Sammanfattning : The role of hybridization in evolution has been debated for more than a century regarding bryophytes (mosses, liverworts, and hornworts) as well as most other organisms. Bryophytes have haplodiplontic life cycles with a dominant haploid generation. LÄS MER

  4. 3. Evolutionary Processes and Hybridization within the Peat Mosses, Sphagnum

    Författare :Rayna Natcheva; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; taxonomi; morfologi; kemotaxonomi. Växters fysiologi inte kärlväxter .; Sphagnum; bryophytes; morphology; phytogeography; chemotaxonomy. Physiology of nonvascular plants; Systematisk botanik; growth rate; regeneration; evolution; Systematic botany; taxonomy; introgression; maternal inheritance; recombination; hybridizarion;

    Sammanfattning : The aim of this thesis was to reveal details of the interspecific hybridization among bryophytes as exemplified by Sphagnum capillifolium and S. quinquefarium. LÄS MER

  5. 4. The ecological significance of sexual reproduction in peat mosses (Sphagnum)

    Författare :Sebastian Sundberg; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Developmental biology; Bryophyte; colonisation; disturbance; experiment; longevity; mire; safe site; spore; Utvecklingsbiologi; Developmental biology; Utvecklingsbiologi; ekologisk botanik; Ecological Botany;

    Sammanfattning : Peat mosses (Sphagnum) are widely distributed and are a major component of mire vegetation and peat throughout the boreal and temperate regions. Most boreal Sphagnum species regularly produce sporophytes, but the ecological role of the spore has been questioned. LÄS MER

  7. 5. Metapopulation and metacommunity processes, dispersal strategies and life-history trade-offs in epiphytes

    Författare :Swantje Löbel; Håkan Rydin; Tord Snäll; Lars E. Ericson; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; asexual; biodiversity; bryophytes; dispersal limitation; establishment; evolution of reproductive traits; germination; growth; habitat fragmentation; landscape dynamics; local processes; patch-tracking; pH; reproduction; species richness; species interactions; Other biology; Övrig biologi; Ecological Botany; Ekologisk botanik;

    Sammanfattning : The aim of this thesis was to increase knowledge about metapopulation and metacommunity processes in patchy, dynamic landscapes, using epiphytic bryophytes as a model system. Host trees and deciduous forest stands in the coniferous landscape are patchy, temporal and undergo changes in habitat quality during succession. LÄS MER