Final Report Summary - GLOBAM (Global biodiversity of arbuscular mycorrhizal fungi: taxonomic and functional patterns)
Glomeromycota - Arbuscular mycorrhizal fungi (AMF) - are living in soil and plant roots as essential partners of most plants in natural and man-made habitats. Understanding natural distribution of AMF is hampered by their microscopical nature and hidden habitat in soil. Molecular methods have opened new opportunities to understand the life of these organisms. The project had three objectives:
(1) describe the biodiversity patterns of Glomeromycota in plant roots in selected global biodiversity hotspots;
(2) develop global database of Glomeromycota identified in plant roots;
(3) identify the functional diversity patterns of Glomeromycota in a well-studied ecosystem - boreo-nemoral forest.
Global diversity patterns of Glomeromycota
Fieldworks were carried out to collect arbuscular mycorrhizal root samples from worldwide locations: Negev desert in Israel, tropical rainforests, temperate forests in Russian Far East, savanna and fynbos ecosystems in South Africa, etc. First data show that all sampling locations yield new Glomeromycota species. As a result of these activities, the understanding of global Glomeromycota diversity is substantially improved.
Glomeromycota diversity was also assessed in invasive palm species roots in its' native habitat in China, invasive range in Switzerland and experimentally introduced localities across Europe. This plant was mostly associating with fungal species that are habitat generalists. This is an important finding that contributes to our understanding of roles of symbiotic organisms in plant invasion.
Database of Glomeromycota
Published DNA sequences of Glomeromycota from ecological surveys and taxonomic publications were collected together with information about host plant, habitat, etc. As a unique feature, unified nomenclature for Glomeromycota DNA-based species (virtual taxon) delimitation was implemented allowing easy comparison of individual case studies. The database MaarjAM is open-access: http://maarjam.botany.ut.ee.
The gathered data show that majority of Glomeromycota species have limited distribution in climatic zones and at continents, and that fungi with wider host range are also more widely distributed in space. The results imply that soil-dwelling organisms such as Glomeromycota do show biogeographic patterns. Thus global transport of soil and plant roots with potting plants, inoculum (bio-fertilisers), ornamental and agricultural growth substrates has a potential to distribute these fungi with unknown impacts on local diversity of soil organisms.
Functional diversity patterns of Glomeromycota
We described communities of Glomeromycota in a 10x10 m plot in Koeru boreo-nemoral forest, a well studied field site in Estonia. Forest specialist plants were colonised by forest inhabiting fungi and habitat generalist plants were colonised by habitat generalist fungi. This work was the first one where novel next generation sequencing (454 sequencing) was applied to study diversity of AMF. This breakthrough in methodology resulted in orders of magnitude more data, and in large increase in detected species richness.
The Koeru fungi have different impact on plant growth. By using whole soil inoculum from differently managed forest stands and from arable field, applied to three plant species, we found that plant growth was dependent on the origin of the fungal community (soil inoculum). The number of fungal species colonising roots of different plant species differed upon application of the same fungal inoculum. This provides experimental support to above finding from field conditions that there is selectivity between plant and fungal symbionts in the arbuscular mycorrhizal symbiosis.
Information about the publications and research activities stemming from this project can be found at the web page of Plant Ecology Laboratory, University of Tartu, led by Prof. Martin Zobel at http://www.botany.ut.ee/planteco/.
(1) describe the biodiversity patterns of Glomeromycota in plant roots in selected global biodiversity hotspots;
(2) develop global database of Glomeromycota identified in plant roots;
(3) identify the functional diversity patterns of Glomeromycota in a well-studied ecosystem - boreo-nemoral forest.
Global diversity patterns of Glomeromycota
Fieldworks were carried out to collect arbuscular mycorrhizal root samples from worldwide locations: Negev desert in Israel, tropical rainforests, temperate forests in Russian Far East, savanna and fynbos ecosystems in South Africa, etc. First data show that all sampling locations yield new Glomeromycota species. As a result of these activities, the understanding of global Glomeromycota diversity is substantially improved.
Glomeromycota diversity was also assessed in invasive palm species roots in its' native habitat in China, invasive range in Switzerland and experimentally introduced localities across Europe. This plant was mostly associating with fungal species that are habitat generalists. This is an important finding that contributes to our understanding of roles of symbiotic organisms in plant invasion.
Database of Glomeromycota
Published DNA sequences of Glomeromycota from ecological surveys and taxonomic publications were collected together with information about host plant, habitat, etc. As a unique feature, unified nomenclature for Glomeromycota DNA-based species (virtual taxon) delimitation was implemented allowing easy comparison of individual case studies. The database MaarjAM is open-access: http://maarjam.botany.ut.ee.
The gathered data show that majority of Glomeromycota species have limited distribution in climatic zones and at continents, and that fungi with wider host range are also more widely distributed in space. The results imply that soil-dwelling organisms such as Glomeromycota do show biogeographic patterns. Thus global transport of soil and plant roots with potting plants, inoculum (bio-fertilisers), ornamental and agricultural growth substrates has a potential to distribute these fungi with unknown impacts on local diversity of soil organisms.
Functional diversity patterns of Glomeromycota
We described communities of Glomeromycota in a 10x10 m plot in Koeru boreo-nemoral forest, a well studied field site in Estonia. Forest specialist plants were colonised by forest inhabiting fungi and habitat generalist plants were colonised by habitat generalist fungi. This work was the first one where novel next generation sequencing (454 sequencing) was applied to study diversity of AMF. This breakthrough in methodology resulted in orders of magnitude more data, and in large increase in detected species richness.
The Koeru fungi have different impact on plant growth. By using whole soil inoculum from differently managed forest stands and from arable field, applied to three plant species, we found that plant growth was dependent on the origin of the fungal community (soil inoculum). The number of fungal species colonising roots of different plant species differed upon application of the same fungal inoculum. This provides experimental support to above finding from field conditions that there is selectivity between plant and fungal symbionts in the arbuscular mycorrhizal symbiosis.
Information about the publications and research activities stemming from this project can be found at the web page of Plant Ecology Laboratory, University of Tartu, led by Prof. Martin Zobel at http://www.botany.ut.ee/planteco/.