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Visar resultat 1 - 5 av 8 avhandlingar som matchar ovanstående sökkriterier.

  1. 1. Functional Diversification among MADS-Box Genes and the Evolution of Conifer Seed Cone Development

    Författare :Erika Groth; Peter Engström; Karolina Tandre; Tom Gerats; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; conifer; seed cone; evo-devo; morphology; plant development; plant evolution; gene family; gene evolution; AGAMOUS; MADS-box; transcription factor; Picea; Cryptomeria; Thujopsis; Juniperus; Biology; Biologi; Biologi med inriktning mot fysiologisk botanik; Biology with specialization in Physiological Botany;

    Sammanfattning : MADS-box genes are important regulators of reproductive development in seed plants, including both flowering plants and conifers. In this thesis the evolution of the AGAMOUS subfamily of MADS-box genes, and what the ancestral function of this group of genes might have been in the early seed plants about 300 million years ago, was addressed by the discovery of two novel conifer genes, both basal to all previously known AGAMOUS subfamily genes. LÄS MER

  3. 2. Improved seed handling techniques for Juniperus polycarpos : implications for active restoration of degraded Juniper forests in Iran

    Författare :Abolfazl Daneshvar; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES;

    Sammanfattning : Juniperus polycarpos (K. Koch) is one of six native juniper forest tree species in Iran whose population size is declining continuously. The ultimate aim of the research presented in this thesis was to increase the regeneration potential of J. LÄS MER

  4. 3. Description of spatial and temporal distributions of epiphytic lichens

    Författare :Håkan Lättman; Per Milberg; Bengt Gunnar Jonsson; Linköpings universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; centroid; continuity; lichen; movement; range shift; direction; dispersal; ecological continuity; establishment; global change; global warming; habitat availability; håkan lättman; Biology; Biologi;

    Sammanfattning : Lichens are, in most cases, sensitive to anthropogenic factors such as air pollution, global warming, forestry and fragmentation. Two studies are included in this thesis. The first is an evaluation of the importance of old oak for the rare epiphytic lichen Cliostomum corrugatum (Ach.) Fr. LÄS MER

  5. 4. Plant-Derived Chemicals as Tick Repellents

    Författare :Samira Sadek Garboui; Thomas Jaenson; Katinka Pålsson; Raimondas Mozuraitis; Uppsala universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Ixodes ricinus; plants; essential oils; tick repellent; Sweden; Biology; Biologi;

    Sammanfattning : Ixodes ricinus is the main vector of Lyme borreliosis and Tick-borne encephalitis in Europe. Repellents provide a practical means of protection against tick bites and can therefore reduce transmission of tick-borne diseases. LÄS MER

  7. 5. Getting to know Trioza apicalis (Homoptera: Psylloidea) – a Specialist Host-Alternating Insect with a Tiny Olfactory System

    Författare :Lina Kristoffersen; Biologiska institutionen; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; Physiology of invertebrates; Djurs anatomi och morfologi; Entomologi; plant parasitology; Entomology; Ekologi; Ecology; glomeruli; antennal lobe; olfactory receptor neurons electrophysiology; antennae; behaviour; olfaction; Sternorrhyncha; psyllid; Ryggradslösa djurs fysiologi; animal morphology; Animal anatomy; växtparasitologi;

    Sammanfattning : This thesis comprises ecological, morphological and physiological studies of the carrot psyllid Trioza apicalis (Homoptera: Psylloidea) with particular focus on olfaction. Data from inventories of winter habitats suggest that T. apicalis prefer Picea abies over Pinus sylvestris and Juniperus communis as winter hosts. LÄS MER