Plant breeding for organic and sustainable, low-input agriculture

Prebreeding methods used on Portuguese maize germplasm and its applications for
on-farm conservation.
Pedro Mendes Moreira 1 , Carlota Vaz Patto 2 , João Santos 1 , Liliana Morgado 1 , João Santos 1 ,
Silas E. Pêgo 3
1 Escola Superior Agrária de Coimbra, Coimbra, Portugal;
2 Instituto de Tecnologia Química e Biológica, Universidade Nova de Lisboa, Oeiras, Portugal;
3 Instituto Nacional de Recursos Biológicos/Estação Agronómica Nacional, Oeiras, Portugal.
After its introduction from America, by Columbus, maize was spread over Portugal and evolved
in an enormous range of natural cultivation conditions (e.g. topography, microclimate, precocity,
pest and disease resistance). This process gave place to the development of different landraces,
i.e., genetic adaptation under human selection. These maize landraces, mass reservoirs of genetic
adaptability, have therefore a valuable conservation function, justifying the existence of a
participatory conservation program. Subjacent to the conservation of maize germplasm, a
Participatory Maize Breeding (PMB) project was initiated in 1984 by Silas Pêgo in the Sousa
Valley (VASO), Portugal. This project was planned to answer the problems of small farmers, i.e.
increasing yield without losing the parameters defined and important to the farmers, as suitability
for polycrop systems, quality and adaptability to low input sustainable agriculture.
In order to screen new potential germplasm, either for classical breeding, either for on-farm
conservation and breeding projects, where adaptation to organic farming and polycrop systems
could be easily fitted, some pre-breeding methodologies, according to Pêgo, are being used (e.g.
Hunters, Overlapping Index).
Landraces obtained from collecting missions are being submitted to Hunters, Overlapping Index
and ear characterization methods. Yield trials are also being done.
The results obtained from the pre-breeding evaluations are being used for future implementation
of new on farm breeding and conservation programmes. A holistic approach should be done
taking into consideration:
1) Genetic resources conservation and conservation of specific agroecological, cultural and
biological processes (e.g. co-evolution process).
2) Farmer “erosion” and impact of local authorities support on marginal areas agriculture.
Community recognition for the complex work done by farmer (e.g. food production, genetic
resources conservation, environmental sustainability, forest protection).
3) Development of the lacking appropriate legislation allowing the certification of OPV with a
certain level of heterogeneity, in order to ease distribution and commercialization.
4) Landraces use to create new high market value products that could be associated with organic
farming.
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