Forty-eight genotypes representing wheat diversity from the Island of
Madeira were screened for resistance to aluminum (Al) in nutrient
solution. Seeds of wheat used in the experiments were obtained from
local farmers. The soil pH and content of ionic Al of plots cultivated with wheat were analyzed. The pH of topsoils varied between 3.83 and 6.59.
The amount of ionic Al in soil samples varied between 0.38 and 1.36
cmol Al3 + per kg of soil and was positively correlated with the altitude
of a plot. Eriochrome cyanine staining was used to evaluate the effect of
Al ions on the root elongation. Seventy-two hour exposure of 3-day-old
seedlings to 100 and 200 mM Al in nutrient solution revealed a high
number of Al resistant genotypes among wheat germplasm. After
withdrawal of Al stress, survival and root regrowth was observed in 28
and 23 genotypes screened at 100 and 200 mM Al in nutrient solution,
respectively. Enhanced resistance to Al among Madeiran genotypes was
associated with the amount of ionic Al in the soils. Complexity and
various patterns of responses of tested cultivars to Al stress may suggest
that Madeiran germplasm could be a valuable source of genes controlling
Al resistance for conventional breeding programs and for studies of
molecular bases of mechanisms of Al resistance.Portuguese Foundation for the Science and Technology (FCT, Fundac¸o
para a Cieˆncia e Tecnologia) has sponsored this work, through the Centre of
Biological and Geological Sciences (C.C.B.G.) and the project POCTI/no.
33005/AGR/1999. The authors are also grateful to the Madeiran Centre of
Science and Technology (CITMA) for financial support. Acknowledgements are due to Mr. Roge´rio Correia and Juan Silva for the technical
assistance in conducting the laboratory and fieldwork and to Dr. Andrzej
Aniol for valuable advice during preparation of this manuscript.info:eu-repo/semantics/publishedVersio
