Sökning: "photoperiod"

Visar resultat 16 - 20 av 25 avhandlingar innehållade ordet photoperiod.

  1. 16. The brain-pituitary-gonadal axis of the three-spined stickleback, Gasterosteus aculeatus

    Författare :Yi Ta Shao; Bertil Borg; Sylvie Dufou; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; BPG axis; GnRH; lh-β; fsh-β; three-spined stickleback; Gasterosteus aculeatus; homeostasis; feedback; funktionell zoomorfologi; Functional Zoomorphology;

    Sammanfattning : The seasonal reproduction of the three-spined stickleback is stimulated by long day photoperiod. As in other vertebrates, the reproductive system of stickleback is regulated by the brain-pituitary-gonadal (BPG) axis which is largely controlled by feedback effects. Both negative and positive feedback effects on the BPG axis have been found in fish. LÄS MER

  2. 17. Understanding the environmental regulation of tree phenology

    Författare :Tetiana Svystun; BECC: Biodiversity and Ecosystem services in a Changing Climate; []
    Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Phenological events; environmental cues; temperature response; phenological modelling; frost risk; gross primary production; climate change impact;

    Sammanfattning : In temperate and boreal climates, trees synchronise their annual growth cycles with seasonal changes in daylength and temperature. Understanding how environmental cues regulate tree phenology is important to our ability to capture the potential responses of trees to climate change, with implications for forest productivity. LÄS MER

  3. 18. Studies on Natural Variation and Evolution of Photoperiodism in Plants

    Författare :Karl Holm; Ulf Lagercrantz; Martin Lascoux; Seth Jon Davis; Uppsala universitet; []
    Nyckelord :photoperiodism; circadian; flowering time; natural variation; evolution; Caspella bursa-pastoris; Physcomitrella patens; Biologi med inriktning mot evolutionär funktionsgenomik; Biology with specialization in Evolutionary Functional Genomics;

    Sammanfattning : Photoperiodism refers to the organism’s ability to detect and respond to seasonal changes in the daily duration of light and dark and thus constitutes one of the most significant and complex examples of the interaction between the organism and its environment. This thesis attempts to describe the prevalence of variation in a photoperiodic response, its adaptive value, and its putative genetic basis in a common cruciferous weed, Capsella bursa-pastoris (Brassicaceae). LÄS MER

  4. 19. Tree phenology modelling in the boreal and temperate climate zones : Timing of spring and autumn events

    Författare :Cecilia Olsson; Institutionen för naturgeografi och ekosystemvetenskap; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

    Sammanfattning : Plant phenology in the boreal and temperate climate zones is synchronised with seasonal changes in temperature and photoperiod. For deciduous trees, timing of budburst and leaf colouring define the growing season length and express adaptations to trade-offs in growth and risks. LÄS MER

  5. 20. Roles of LESIONS SIMULATING DISEASE1 and Salicylic Acid in Acclimation of Plants to Environmental Cues : Redox Homeostasis and physiological processes underlying plants responses to biotic and abiotic challenges

    Författare :Alfonso Mateo; Stanislaw Karpinski; Philip M. Mullineaux; John F. Allen; Stockholms universitet; []
    Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; LSD1; Photooxidative stress; Reactive oxygen species; Light acclimation; Photorespiration; Salicylic acid; Plant physiology; Växtfysiologi;

    Sammanfattning : In the natural environment plants are confronted to a multitude of biotic and abiotic stress factors that must be perceived, transduced, integrated and signaled in order to achieve a successful acclimation that will secure survival and reproduction. Plants have to deal with excess excitation energy (EEE) when the amount of absorbed light energy is exceeding that needed for photosynthetic CO2 assimilation. LÄS MER