Marjo Helander profile picture
Researcher, Ecology and Evolutionary Biology
Docent, Faculty of Science
Docent, PhD


+358 29 450 4212
+358 50 409 7259
Vesilinnantie 5

Areas of expertise

fungal ecology


I’m a Turku University graduate (plant) ecologist. My main research interest are plants, plant associated microbes (endophytic and epiphytic microbes, mycorrhizal fungi, pathogens) and herbivores and their interactions. For over twenty years, our model system has been grasses (genus Festuca) and their systemic seed transmitted endophytes (Epichloë sp.). During last decade my research has focused more on agricultural systems and the effects of agrochemicals (glyphosate) on non-target organisms. To answer our research questions we use long-term common-garden and field experiments from where we get material and data for laboratory analyses and modelling.

I have conducted most of my research projects together with my husband Kari Saikkonen (Prof., Biodiversity Unit, University of Turku). Our research questions have taken us to Arizona (Arizona State University, 1995-1997) and to the center of grass-endophyte studies in Kentucky (2014) as well as to collect grass samples circumpolarly (e.g. Greenland, Canada, Faroe Islands). We are actively collaborating with several grass-endophyte research groups in Europe and North and South America.


My teaching includes courses on plant-microbe-herbivore interactions, and agroecology and -evolution. Most of my teaching is, however, supervising bachelor's, master's and PhD thesis, which are usually part of our ongoing research projects.


I’m leading an Academy of Finland funded research project (2017-2021) ‘Effects of glyphosate on non-target organisms’.

Glyphosate is the most used pesticide globally. Its herbicidal activity is based on inactivation of an enzyme of the shikimate metabolic pathway, and it thus kills non-selectively herbaceous plants. It has been regarded harmless to animals and humans, because the shikimate pathway does not occur in animals. However, it can be found in many microbes. Thus, glyphosate may affect the microbial activity and modify microbial community of the soil, plants and other interacting organisms. In our project we take advantage of novel technologies to examine microbiota in plants and animals, their interactions in plants via phytohormone signaling pathways, and the effects of glyphosate on secondary plant defense chemicals, plant performance, and performance and well-being of both invertebrate and vertebrate animal model species. The project leans on experimental field site (founded in 2014) simulating the till/no-till cultivation using replicated plots with and without glyphosate application in University of Turku Botanical Garden. We have chosen important Finnish crops (broad horse bean, potato, meadow fescue, oat, strawberry) as model plants in the field experiment to study indirect plant associated microbe responses to glyphosate application. Direct glyphosate effects on herbivores via food on life history traits and physiological responses and gut microflora are studied on mealworms and Japanese quails. Indirect effects of glyphosate via soil on herbivores are studied using Colorado potato beetles as model organism. Our project is aiming to gain a holistic view of possible glyphosate effects in the agroecosystem.


Sort by: