Schriften zu Genetischen Ressourcen - Genres

B. PICKERSGILL, M.I. CHACÓN SÁNCHEZ and D.G. DEBOUCK
number of cultivar-groups to be discriminated. For example, cultivar-group names
such as White Headed Cabbage or Savoy Headed Cabbage (JANSEN et al. 1994) are
in some danger of becoming as lengthy as the pre-Linnaean phrase names which
were abandoned in favour of the simpler binomial system.
When a crop was domesticated more than once, as in common bean, this cannot
easily be reflected in its taxonomy, because the Cultivated Code provides only the
single category of cultivar-group to encompass all variation between genus or species
and cultivar. Growers or consumers of cultivated plants do not need names that
reflect the evolutionary history of what they are growing or eating. Probably only
those concerned with conservation and utilisation of genetic resources of a crop
really need such information. Since we have shown that evolutionary history of a crop
cannot be adequately reflected using the categories provided by the Cultivated Code,
informal categories will no doubt continue to be invented and used. In Phaseolus vulgaris,
the informal categories of gene pool and race have served well to communicate
our present understanding of evolution and genetic diversity in this species.
Whether this will continue to be true when we have the more detailed phylogenies
which DNA studies promise to deliver, only the future will tell. However, the data currently
available suggest that there may be both challenges and surprises ahead.
References
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BEEBE, S., P.W. SKROCH, J. TOHME, M.C. DUQUE, F. PEDRAZA and J. NIENHUIS (2000):
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BEEBE, S., J. RENGIFO, E. GAITAN, M.C. DUQUE and J. TOHME (2001): Diversity and
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CHACÓN SÁNCHEZ, M.I. (2001): Chloroplast DNA polymorphisms and the evolution
and domestication of the common bean (Phaseolus vulgaris L.). Ph.D. thesis,
The University of Reading, UK.
DEBOUCK, D. (1991): Systematics and morphology. In: A. VAN SCHOONHOVEN AND O.
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DEBOUCK, D.G., O. TORO, O.M. PAREDES, W.C. JOHNSON and P. GEPTS (1993): Genetic
diversity and ecological distribution of Phaseolus vulgaris (Fabaceae) in
northwestern South America. - Econ. Bot. 47: 408-423.
FREYRE, R., R. RIOS, L. GUZMAN, D.G. DEBOUCK and P. GEPTS (1996): Ecogeographic
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