The University of The West Indies
Mycorrhizae Research Group
Current Research Projects
Page under construction
An assessment of the VA
mycorrhizal potential of some Barbadian soils
Agriculture in Barbados takes place on a wide range of soil types.
Samples of soil were collected and each divided into three subsamples.
Two sets of subsamples were placed in flower pots and non-mycorrhizal
bean, pepper and corn plants transplanted into one set. The second set
was planted with corn seeds. The phytometers were harvested at
one week intervals and their roots assessed for VAM fungal colonisation.
The remaining subsamples were wet-seived to determine spore populations.
Results from this project were presented at the 32nd Annual Meeting
of the Caribbean Food Crops Society in Honduras, 7-13 July 1996
and at the First International Conference on Mycorrhizae, University of
California at Berkeley, 4-9 August 1996.
(
Abstract at the ICOM 1 site).
Effects of insecticides on VA
mycorrhizas of corn and Gigasporaceae
A recent student project showed that insecticides can have a negative
effect on plant growth. This may be a direct effect or it could involve
interaction between the insecticides and mycorrhizal fungi.
Little (nothing?) is known about the impacts of the newer types of
insecticides on these fungi.
Spores of local isolates of Gigaspora and Scutellospora
and germinated corn were planted in autoclave sterilised soil/sand/vermiculite.
Once the mycorrhizas are fully established, the plants will be treated
with insecticides.
We also plan to conduct spore germination tests in various insecticides.
Promoting transformation of Gigaspora
With funding from the International Foundation for Science (IFS),
attempts are being made to isolate the promoter from the gene encoding
actin in Gigaspora. Actin is a highly conserved protein and is
coded by a single gene in fungi. PCR primers, designed from conserved
upstream regions of fungal actin gene accessions from GENBANK,
were synthesised and being used to amplify the homologous actin gene
sequence from Gigaspora DNA. It is likely that the inverse of
these primers will be used to identify the promoter region of the
Gigaspora actin gene by inverse PCR. The promoter when identified
will be isolated and cloned into a plasmid, pSPC01, for transformation.
Such a transformation system when developed, would facilitate genetical
studies to be conducted on VA mycorrhizae, to better understand and
enhance the association these fungi have with plant roots.
So far, the generation of protoplasts from VA mycorrhizal hyphae have
been unsuccessful. If anyone has suggestions, we would be happy to hear
from you.
Susan Persad-Chinnery
The Mycorrhizal Status of Bletia
purpurea (Lam.) DC.
Most terrestrial orchids are dependent on a mycorrhizal symbiont for at
least part of their life cycle. The mycorrhizal status of the Barbados
ground orchid is not known. Recently, interest has been developed on
the fungal symbionts involved in orchid mycorrhizae. These, unlike those
involved in the vesicular-arbuscular mycorrhizal symbiosis, can be axenically
cultured and are taxonomically diverse.
In this project, the roots of B. purpurea are being examined for
mycorrhizal fungal structures. Any fungi present will be cultured and
identified.
The Mycorrhizal Status of Pteris vittata L.
A number of authors, supported by some fossil evidence, have suggested
that the colonisation of land by early terrestrial plants was facilitated
by fungi which form (vesicular-) arbuscular mycorrhizae (vam). More
recently, it has been reported that the ericoid type of mycorrhiza has
been found in ferns. This mycorrhizal type was formerly believed to be
restricted to two families within the Ericales.
The wall fern, P. vittata, is relatively common in Barbados and
grows in what appear to be nutrient poor locations. Locations expected
to favour mycorrhizal development.
In this project, the "roots" of P. vittata are being examined for
mycorrhizal fungal structures. If mycorrhizae other than vam are found,
any fungi present will be cultured and identified.
Opportunities for Graduate Research
The degrees of M.Phil. and Ph.D. by research are offered by
the University of the West Indies. Although it is easier for
Caribbean students to access these programmes, some opportunities
exist for students from other countries.
The University of the West Indies has formal links with a number
of North American and British Universities. Through these links
it is possible for some graduate students to conduct research
in Barbados for degrees from their home institution.
With its year long summer/tropical climate, Barbados is an ideal
place to conduct field based studies.
For more information contact Louis Chinnery
(lec@caribnet.net)
Recent Publications
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This page last updated 23 June 1997