Benedicte Riber Albrectsen - Populus Resistance to Biotic Stress

Home

Plants have evolved numerous ways to escape damage by antagonists. With changing growing conditions, mainly caused by invasive species and effects of global warming, our forests may be increasingly challenged by biotic stresses.
I am interested in all aspects of plant resistance that may help us understand how the risk of biotic stress may be reduced, including chemical and mechanical defence traits, tolerance, phenology displacement and ecological interactions that rescue plants from attack by antagonists. Currently, in my lab, we concentrate on studies of Populus sp. from four points of view.

Benedicte_Albrectsen_prtrait

Trait association studies and large scale patterns in Populus We relate a number of phenotypic traits measured on Populus tremula genotypes in the field to assess heritability and resistance to herbivores and pathogens. The biobanks SwAsp (116 clones) and UmeAsp (450 clones) are important for these studies. Since 2004, damage to the SwAsp collection has been followed in the field in a G by E setup. We ask if geographical origin matters for resistance properties in clones. Extreme clones (with intensive growth, early bud set, heavy damage by certain antagonists etc.) have been identified for later experimentation in bioassay and plant response studies in the laboratory.

Chemical profiling
We characterise secondary and primary metabolites in Populus leaves from the SwAsp biobank to determine palatability to insect herbivores and susceptibility to pathogens. We are interested in how genotypes may change under different environmental stresses and we ask how this plasticity and ability to acclimate may affect susceptibility to antagonists. We particularly focus on the phenylpropanoid pathway. For these traits too, we search for extreme clone behaviour (for example, high levels of certain phenolics, sugars or amino acids) and relate them to association studies in the field.

Studies on induced responses in aspen
We challenge extreme clones by introducing antagonists in whole plant assays or on detached leaves. We have mainly worked with the aphid Quitophorous populetii, the beetle Phratora vitellinae, simulated damage and the disease Melampsora magnusiana. The aim with these studies is to compare clone-specific responses in the metabolome to different types of damage, to test theories about clone and antagonist-specific induction in Populus.


Some typical arthropods encountered in our common gardens: 1. Harmandia tremula a leaf-galling mite, 2. Bycticus sp. a leaf rolling weevil, 3. Chrysomela populi a leaf beetle that oviposits and chews on leaves, 4. Phyllocnistis labyrintella a leaf mining butterfly.

Bioassays with bioagents

Primary and secondary chemical compounds are extracted from aspen leaves to assess their value as feeding attractants and repellents. We use simple colorimetric analyses as well as advanced mass spectrometric separation techniques to study compounds of interest.

We have cultured the leaf beetle Phratora vitellinae and three aphid species of the Quitophorous genus to perform bioassays in the lab. We use choice and no-choice tests to describe preferences and performance of the insects when fed on extreme genotypes.

Svensk sammanfattning...

Key publications

Albrectsen BR, Björkén L, Varad A, Hagner Å, Wedin M, Karlsson J and Jansson S (2010)
Endophytic fungi in european Aspen (Populus tremula) leaves – diversity, detection, and a suggested correlation with herbivory resistance. Fungal Diversity.

Albrectsen BR, Witzell J, Robinson K, Wulff S, Luquez VMC, Ågren R and Jansson S (2009) Large scale geographic clines of parasite damage to Populus tremula L. Ecography.

Crutsinger G, Sanders NJ, Albrectsen BR, Abreu IN and Wardle DA (2008) Ecosystem retrogression leads to increased insect abundance and herbivory across an island chrono sequence. Functional Ecology.

Luquez Virginia, Hall D, Albrectsen BR, Karlsson J, Ingvarsson P and Jansson S (2008) Natural phenological variation in aspen (Populus tremula): the SwAsp collection. Tree Genetics & Genomes.

Albrectsen BR, Guiterrez L, Fritz RS, Fritz RD, Orians CM (2007) Does the differential seedling mortality caused by slugs alter the foliar traits and subsequent susceptibility of hybrid willows to a generalist herbivore? Ecological Entomology.

Fritz Robert S, Hochwender CG, Albrectsen BR, Czesak ME (2006) Fitness and genetic architecture of parent and hybrid willows in common gardens. Evolution 60 (6): 1215-1227.

Expand List of publications...

July 2010

Friday, July 30, 2010
Random Picture (25.jpg)