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Visar resultat 1 - 5 av 16 avhandlingar som matchar ovanstående sökkriterier.

1. 1. Dynamics of the aphid-ant mutualism

   Författare :Karolina Tegelaar; Olof Leimar; Judith Bronstein; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; mutualism; transgenerational; aphids; aphid-ant; conflict of interest; E -β-farnesene; phenotypic plasticity; predation risk; wing induction; maternal effect; reproductive investment; embryo size; etologi; Ethology;

   Sammanfattning : An appreciation of the role of mutualism is essential when studying ecology and evolution in most ecosystems. Information covering aspects of mutualistic interactions can serve as a complement to the somewhat one-sided perspective from the 1950’s and 60’s that is used when teaching biology. LÄS MER

3. 2. Barley defense genes against aphids

   Författare :Aleksandra Losvik; Lisbeth Jonsson; Ulla Rasmussen; Robert Glinwood; Bogumił Leszczyński; Stockholms universitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES; Aphid resistance; protease inhibitor; lipoxygenase; induced plant resistance; volatiles; Hordeum vulgare; Rhopalosiphum padi; Myzus persicae; Plant Physiology; växtfysiologi;

   Sammanfattning : Aphids are insect pests with major importance worldwide. By feeding from plant phloem, they directly withdraw nutrients. The feeding injury is often visible in the form of leaf rolling, chlorosis, necrosis or plant deformation. Their pest status is attributed also to vectoring of plant viruses. LÄS MER

4. 3. Biodiversity and biological control : effects of agricultural intensity at the farm and landscape scale

   Författare :Camilla Winqvist; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :LANTBRUKSVETENSKAPER; AGRICULTURAL SCIENCES; NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Agricultural intensity on the local field or farm scale and on the regional landscape scale affects the organisms utilizing the arable landscape, and may affect ecosystem services and functions. This thesis examines how plants, birds, community composition of ground beetles, and biological control of cereal aphids are affected by local agricultural intensity, organic farming and the surrounding landscape in Sweden and across Europe. LÄS MER

5. 4. Insights into biotic stress response in Arabidopsis thaliana : the roles of epigenetics and RNA silencing

   Författare :María Luz Annacondia López; Sveriges lantbruksuniversitet; Sveriges lantbruksuniversitet; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES;

   Sammanfattning : Plants live in fluctuating environments that can lead to stressful conditions that threat their survival. To deal with these disturbances, plants have developed a fascinating genome plasticity that enables them to reprogram their gene expression and adapt to the new conditions. LÄS MER

7. 5. Stress Related Emissions of Norway Spruce Plants

   Författare :Marie Pettersson; Anna-Karin Borg-Karlson; Torkel Berglund; Åsa Emmer; KTH; []
   Nyckelord :NATURVETENSKAP; NATURAL SCIENCES; volatiles; terpenes; green leaf volatiles; stress response; nepetalactone; SPME; Picea abies; Hylobius abietis; Cinara pillicornis; Chemistry; Kemi;

   Sammanfattning : The interactions between plants and insects are mediated by volatile molecules. Plants respond to stress by biosynthesis of chemical substances which can deter invading insects or pathogens. Some of these substances are volatile and are emitted to the surroundings and may attract or repel insects. LÄS MER