Werkgroep Mycorrhiza

Programma Mycorrhiza Bijeenkomst 23 september 2004

Verslag (M$-Word) van deze meeting

Locatie: Wageningen Universiteit, Leerstoelgroep Natuurbeheer en Plantenecologie, Bornsesteeg 69, Wageningen.

11.00 Ontvangst met koffie en thee
11.30 Roy Grunsven en Anita Kikkert (WUR) - The role of AMF in plant invasions.
12.00 Marcel van der Heijden (VU) - The mycorrhizal contribution to plant diversity, soil formation and nutrient uptake in grassland
12.30 Lunch & rondleiding
13.45 Chris Kik (PRI-WUR) – The secret life of an onion
14.15 Istvan Paradi (PPO-WUR) – The underwater world: a view on different mycorrhizal communities
14.45 Aafke Brader (VU) – Effects of different AMF on legume and non-legume growth
15.15 Theepauze
15.30 Jan Colpaert (LUC)- Cu tolerance in Suillus luteus protects pines against Cu toxicity
16.00 Philippine Vergeer (KUN) – The effect of turf cutting on plant and arbuscular spore colonisation: implications for heathland recovery

Jantineke Zijlstra, Wageningen Universiteit

Jacqueline Baar, PPO-WUR

Report of the 8th Meeting of the Mycorrhizal Group held at September 26, 2003

At September 26, 2003, the 8th meeting of the mycorrhizal group was held at the Limburgs Universitair Centrum in Diepenbeek, Belgium. The meeting was well attended by twenty people. Seven interesting presentations were given which were followed by good discussion. A few presentations will be highlighted.

Dr. Bernard Moyersoen gave a presentation about the occrrence of Pisolithus species in the Taupo area in New Zealand. An interesting result of his research was that some Pisolithus species live in an environment that makes someone think of hell. These Pisolithus species were found in thermal areas with soil temperature of 50ºC. The results provided by the molecular techniques (PCR, RFLP, cloning and sequencing) applied, indicated that the Pisolithus species were blown over from Australia to New Zealand.

Dr. Jan Colpaert (LUC, Diepenbeek) presented a study to the Zn-tolerance of several ectomycorrhizal species associated with Pinus sylvestris. It was shown that different species vary in their tolerance for Zn. For instance, Suillus luteus is an ectomycorrhizal species that is tolerant to Zn while a species as Paxillus involutus is hardly tolerant to Zn. These differences in tolerance may be related to the ecology of the species. Suillus luteus is mostly found at mineral soil without accumulated litter while Paxillus involutus occurs at accumulated litter. Ludo Muller (LUC, Diepenbeek) showed the results of his molecular study on variation within the species Suillus luteus in relation to Zn-tolerance. The molecular technique AFLP was applied to study such variation.

Ir. Mark Smits (WUR, Wageningen) presented a study about the weathering of rocks caused by ectomycorrhizal fungi. He showed a comparison between two chronosequences, one in Michigan, U.S.A. and one in Sweden. In these chronosquences, Marks Smits works on an ongoing study to the forming of tunnnels that is assumed to be caused by ectomycorrhizal fungi that excrete acids.

The presentation of Dr. Marcel van der Heijden (VU, Amsterdam) was about the role of N-fixing bacteria in ecosystems. In an experimental set-up, N-fixing bacteria isolated from the sand dunes near Egmond aan Zee were added to N-fixing (Legumes) and non-N-fixing plant species originating from the sand dunes. Marcel van der Heijden showed that addition of the N-fixing bacteria stimulated the growth of both Legumes and the other plant species. Marcels assumption is that the nitrogen fixed by the N-fixing bacteria is transported by the mycorrhizal fungi. This is currently under study.

Next meeting

The next meeting of the mycorrhizal group will take place at March 26, 2004 and will be hosted by the company Ecostyle in Appelscha.

In the morning there will be several presentations and in the afternoon there will be an excursion to a field site in the neighbourhood.

This meeting will be co-organized by Dr. Ir. J. Baar (jacqueline.baar@wur.nl) and Arjan van der Vinne (a.vandervinne@ecostyle.nl).

These people can be contacted for more detailed information.

A report of the meeting held in Boskoop at March 21, 2003 can be found here.

6th Meeting of the Mycorrhizal Group held at March 29, 2002

At March 29, 2002, the 6th meeting of the mycorrhizal group was held at the RIVM in Bilthoven. The meeting was well organized and sponsored by Van Kampen BIO uit Sprang-Capelle.

The meeting was attended by twenty people despite the beautiful weather at "Good Friday". These people were not disappointed, the presentations were interesting followed by good discussion.

Dr. Fons van Kuik (PPO-WUR) started off with a presentation about a project in which the effects of a product of Plant Health Care containing the ectomycorrhizal fungus Pisolithus tinctorius on the growth of various trees are investigated. This is an ongoing project and in the next meeting Fons will show the first results. Subsequently, Dr. Jacqueline Baar (PPO-WUR) presented a study on mycorrhizal fungi in wet Alder carr forests in The Netherlands. She showed that the dominant tree species Alnus glutinosa is highly ectomycorrhizal, even in wet Alder carr forests on water saturated soils in a peatland and along a stream valley. However, the diversity of the mycorrhizal community below ground was higher in the wet Alder carr forest in the peatland than along the stream valley. Drs. Kristin Adriaensen (LUC) presented her research on the tolerance of heavy metals by ectomycorrhizal fungi. Particularly, she discussed the protection of zinc stressed plants associated with Suillus luteus from nutrient deficiencies.

After the very nice lunch that was offered by the sponsor, the presentations were continued. The first speaker after lunch was Drs. Renske Landeweert (WUR) who showed the vertical distribution of mycorrhizal hyphae in Swedish forest soils. The mycorrhizal communities at different soil depths were determined by molecular methods that enabled identification. The quantification of the various mycorrhizal fungi at different soil depths is still under research. Renske is currently comparing three different molecular methods to develop quantification of hyphae of different mycorrhizal fungi in soil. Drs. Irene Cardoso (WUR) followed with discussing her project on the phosphorus uptake by maize plants associated with mycorrhizal fungi in strongly phosphorus fixing soils in South-America. Particularly, Irene discussed the mechanisms enabling arbuscular mycorrhizal fungi taking up phosphorus under extremely low availability of phosphorus. The final speaker was Dr. Eric Smit (RIVM) who presented a project on the effects of genetically modified bacteria on ectomycorrhizal and arbuscular mycorrhizal fungi. Effects of genetically modified bacteria on ectomycorrhizal and arbuscular mycorrhizal fungi were observed in vitro, but no effects were found in vivo. This presentation was followed by a lively discussion about how harmful genetically modified bacteria could be in the field.

Verslagen van eerder gehouden bijeenkomsten staan hier.