In this paper we attempt to remove the dichotomy created by distinguishing between participatory and non-participatory breeding programmes by using the degree of client orientation as the basis for an analysis. Although all breeding programmes are implicitly client-oriented, we examine how participatory approaches explicitly increase the extent of client orientation. We briefly review the history of participatory plant breeding (PPB) and analyse the participatory techniques used at different stages of the breeding programme. In common with several other authors, we find that farmer involvement in selecting in the segregating generations may not be an essential component of PPB. However, in some circumstances such collaboration is required and is the subject of a second paper in this series. The purpose of all the techniques used in PPB programmes is to better meet the needs of clients. Thus, breeding programmes can be differentiated by their extent of client-orientation removing the dichotomy involved with the term participatory. We discuss four techniques in the suite of techniques that have been employed by PPB: identifying the target market or clients; using germplasm that can best meet the needs of target clients; matching the environments of the target clients; and product testing in the target market with target clients. Most attention is paid to the last of these four that is often referred to as participatory varietal selection (PVS) and how it is done varies with circumstances. Rice varieties from a client-oriented breeding programme in Nepal were tested in mother and baby trials in Bangladesh. The rapid acceptance of these varieties by farmers illustrates the power of the participatory trials system and the success of a highly client-oriented breeding approach.

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Altering root morphology of rice (Oryza sativa L.) cultivars could improve yields in drought-prone upland ecosystems. Marker-assisted backcross breeding was used to introgress four QTLs for root traits into an upland rice cultivar. The QTLs had previously been identified under experimental conditions in a different genetic background. The introgressed lines and the recurrent parent were grown for 6 years by resource-poor farmers in upland sites in Eastern India and yields recorded. In combination the QTLs significantly increased yield by 1 t ha(-1) under relatively favourable field conditions. In less favourable trials, the QTL effects were not detected due to greater heterogeneity in soil-water availability in very low yielding environments and consequent yield variability. Root studies under controlled conditions showed that lines with the introgressions had longer roots throughout tillering than the recurrent parent (14 cm longer 2 weeks after sowing). Therefore, both improved roots and increased yield can be attributed to the introgression of QTLs. This is the first demonstration that marker-assisted backcross breeding (MABC) to introgress multiple root QTLs identified under controlled conditions is an effective strategy to improve farmers' yields of upland rice. The strategy was used to breed a novel upland rice cultivar that has been released in India as Birsa Vikas Dhan 111.

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BackgroundCrop yields have to increase to provide food security for the world’s growing population. To achieve these yield increases there will have to be a significant contribution from genetic gains made by conventional plant breeding. However, the breeding process is not efficient because crosses made between parental combinations that fail to produce useful varieties consume over 99% of the resources.ResultsWe tested in a rice-breeding programme if its efficiency could be improved by using many fewer, but more judiciously chosen crosses than usual. In a 15-year programme in Nepal, with varietal testing also in India and Bangladesh, we made only six crosses that were stringently chosen on complementary parental performance. We evaluated their success by the adoption and official release of the varieties they produced. We then modelled optimum cross number using assumptions based on our experimental results.Four of the six crosses succeeded. This was a fifty-fold improvement over breeding programmes that employ many crosses where only about one, or fewer, crosses in 200 succeed. Based on these results, we modelled the optimum number of crosses by assuming there would be a decline in the reliability of the breeder’s prediction of the value of each cross as more crosses were made (because there is progressively less information on the traits of the parents). Fewer-cross programmes were more likely to succeed and did so using fewer resources. Making more crosses reduced the overall probability of success of the breeding programme.ConclusionsThe efficiency of national and international breeding programmes would be increased by making fewer crosses among more carefully chosen parents. This would increase the number of higher yielding varieties that are delivered to farmers and hence help to improve food security.