Diverse cereal populations are likely to be available soon for marketing. The increase in diversity available to farmers can be exploited through on-farm participatory breeding approaches, leading to the creation of locally adapted lines and populations, which may ultimately result in a decentralisation of the seed supply chain. This session was organised by the Organic Research Centre (ORC)
Nick Fradgley (ORC): chair.
Participatory plant breeding (PPB) programmes are farmer-led plant breeding programmes that has been very well received in parts of the world where small-scale and subsistence farming is prevalent, such as Africa and Asia. Nick Fradgley of ORC began the session by providing an excellent introduction to the role of PPB in the developing world. Parallels were drawn between such subsistence farming in the developing world and organic farming in the UK, notably the variation in growing environments relative to conventionally farmed sites. The session then compared two different approaches to plant breeding, conventional plant breeding and evolutionary plant breeding. Conventional breeding programmes begin by crossing parents from elite lines. Selections are made by a breeder at a centralised breeding station and a select few lines continue onto further testing in the field. Evolutionary plant breeding programmes begin by crossing multiple parents of different backgrounds. The progeny are grown under field conditions and the ‘composite cross population (CCP)’ is allowed to evolve under natural selection pressures. Diversity is maintained throughout the breeding programme, which ultimately results in a field of thousands of individual homozygous lines. CCP provide a great source of genetically variable plant material from which artificial selections can be performed. Selection methods all involve simplification of the CCP by reducing diversity. Negative selection, in which unfavourable plant traits are selected against, can be performed on the CCP. Alternatively positive selection techniques, in which a small selection of lines is chosen to be grown together, may be preferred by the farmer. Further simplification extends towards selection of a single individual line from the CCP that can be bulked up to ultimately be grown as a genetic monoculture. After this overview, the speaker then turned to the audience for opinion on the ideal wheat crop type they would like to have on their farms. The value of straw for animal feed at low energy cost was highlighted. Discussions focussed on to the need for easy, cheap selection methods to allow for farmers to select for more quality parameters than is currently possible. There has been a suggestion that overall protein content may be assessable by eye. Grain samples from lines selected from CCP had been sent for protein analysis and the audience were encouraged to rank the four samples in order of protein content, which most were able to do by eye as the darker grain related to higher protein content. Members of the audience expressed wishes for more specific on-farm quality parameter assessments, such as identification of different proteins in the grain as well as vitamin and mineral composition that related to bread taste and nutritional content.
The discussion that followed the presentations brought out the following points:
- Plant breeding selection criteria will vary according to on-farm growing conditions
- More straw is desirable for weed competition and animal feed at low energy cost
- Selection parameters will vary according to crop end-usage, whether that be feed or milling
- There is a need for cheap and easy on-farm techniques to select for grain quality.
- Investigate farmer friendly quality parameter selection criteria
- Engage farmers directly with PPB approaches