Plant breeding for organic and sustainable, low-input agriculture

Conservation and generation of genetic resources through development of modern
landraces of wheat: co-evolution in the field
Maria R. Finckh
Faculty of Organic Agricultural Sciences, Department of Ecological Plant Protection, University
of Kassel, Witzenhausen, Germany
Over the past 100 years, the biodiversity within varieties and species of field crops in agriculture
has been reduced drastically through plant breeding approaches favouring genetic uniformity for
all traits. This has practically eliminated all co-evolutionary processes between hosts and their
pests and pathogens. It also does not allow for dynamic adaptation of plant populations to
changing environment e.g. climatic change. Breeders and pathologists have all along pointed out
the danger of this approach. In contrast to the modern varieties, for most crops landraces are
characterised by a larger inherent genetic diversity and thus also a higher adpatability. However,
the existing landraces usually are not competitive with modern varieties under current
agricultural conditions due to a lack of systematic population improvement for the past 100 or so
years.
Alternative approaches to pure line breeding have been developed by using composite crosses,
top crosses and population breeding. The “modern landrace” or “evolutionary breeding”
approach aims at combining the advantages of the breeding success of the last century and the
use of genetic variation producing high yielding and high quality but genetically diverse crop
populations that can be adapted to local conditions by the farmers.
Three different winter wheat composite crosses were produced by Elm Farm Research Centre
and the John Innes Institute in 2001 (Wolfe et al, 2006) and are currently maintained at different
sites in Europe under conventional and organic conditions. The overall aim is to provide
materials for interested farmers for the development of locally adapted materials. Research is
being conducted on the evolution of the populations with respect to diversity and adaptation
processes to various selective pressures.
In Germany, the populations are maintained since the F4 under organic and conventional
conditions. Morphological diversity is still high in the currently growing F6 while in contrast to
popular local varieties disease pressure is low. Data on the relevant diseases in 2007 and the
population development with respect to yield and quality parameters will be presented.
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