The adoption and deployment of molecular marker assisted breeding technology (2002-2007)
Affiliated staffSteve Hughes
The goal of this project is to explore and advise upon the ways in which genomics can assist agriculture in developing countries, particularly by making use of local knowledge. It therefore began by exploring the linkages (actual and potential) between these three categories. While no obvious connection between them was apparent, the technology known as molecular markers was selected for further study because:
- it is a truly genomics-based technology, i.e. it is made possible by new understandings of the genome as a whole (in a way that is not generally the case with the development of transgenic plants);
- molecular markers are increasingly used to support the development and provision of improved crops, which is of direct relevance to agriculture in most parts of the developed and developing world.
- the network of international agricultural research centres (CGIAR) has established a ‘Challenge’ programme to support technology development and decentralised capacity building in relation to the application of molecular markers to poor people’s crops. This and similar programmes should benefit from the findings of sociological studies of the adoption of marker technology in the developing world.
The project has explored the ways in which molecular markers (MMs) are used across a range of institutional settings (in Viet Nam, India and China) to support LDC agriculture: to increase the speed and accuracy of quality control in the commercial production of hybrid seeds; to increase the speed of plant breeding; and to extend the scope of plant breeding, making possible the provision of crop varieties with novel combinations of characteristics. One way in which the use of MMs extends the scope of plant-breeding is that it makes it easier to introgress desirable alleles from germplasm collections into the elite crop varieties that agricultural scientists produce. This means that the utility (and thus the value) of genetic resources is, at least in principle, increased by the availability of MMs. Indigenous knowledge about the desirable characteristics of ‘traditional’ plant varieties and their wild relatives could therefore become more important to agricultural researchers, although, no evidence that this is actually happening in the chosen settings has yet been demonstrated.
The empirical study has been based on extended site visits and interviews with local actors and has concentrated on the practical issues that arise from the use of MMs in diverse settings. It is useful to divide these into those involved in (i) establishing new markers for traits that are of interest, (ii) making use of known markers in order to provide farmers with improved planting material. These two activities require different resources (capital equipment, recurrent budgets, skill sets) and so pose distinct policy issues. Marker discovery has, so far, been an expensive, high-tech activity and so is likely to be performed in a limited number of well-capitalised centres, each of which could in principle support breeding programmes throughout the world. Marker application is less expensive and so can be performed at a local level, but still requires an appropriate mix of equipment, access to knowledge networks and to genetic resources, skilled professionals from a range of disciplines and an organisational culture that facilitates the effective deployment of all these resources.
- It has been noted that while marker assisted selection has been available for fifteen years, the literature includes few or no reports of its use leading to released germplasm or varieties.
- A review of UK research relevant to crop science prepared for the Biotechnology and Biological Sciences Research Council states bluntly that “there is little or no evidence to date that the high level of investment in plant science is having a significant impact on strategic and applied research in crop science.”
Reasons for limited impact of marker assisted selection.
- Inadequate links between pure science and applied science, in particular links between breeders and molecular biologists.
- Global decline in academic plant-breeding, with resources being transferred to molecular genetics and transgenic technologies.
- The professionals who are needed to obtain practical benefit from advances in these technologies are no longer being trained in sufficient numbers. The shortage of plant breeders means that the potential contribution offered by molecular markers can only partially be realised.
Location of Research Institutes.
- The high cost of molecular marker discovery imposes an unavoidable pressure for centralisation (to capture economies of scale,) because the process requires expert scientific management and high cost equipment. Each such facility could serve breeding programmes throughout the world, so long as each ‘client’ breeding programme was equipped with the infrastructure necessary for electronic communication and for analysing and interpreting DNA sequence data.
- The diversity of circumstances and agro-environments cultivated by poor farmers means that they require a diverse and decentralised research and plant breeding system. The objectives of any breeding programme should be informed by the characteristics preferred by the farmers who are intended to grow the crop varieties that the programme will produce. Conversations between farmers and breeders can take place more easily if the breeding programme is based near to the farms of its clients.
- In view of the high cost of marker discovery, molecular marker researchers must maintain close links with plant breeders throughout the world, in order to ensure that the markers that they discover are for traits that are indeed of practical importance and are available in breeding lines that show good combining ability with elite cultivars.
Knowledge sharing & infrastructure.
- Professionals may be reluctant to share the knowledge that constitutes their most precious asset. Many professionals have little respect for those outside their field, even when all parties are supposedly seeking the same goal, and so are reluctant to learn from people outside their own profession.
- The discovery and use of valuable markers requires productive collaboration between scientists trained in molecular biology on the one hand, and applied sciences like plant breeding and genetics, pathology and entomology on the other. Since practitioners of each of these specialisms constitute distinct communities, deliberate efforts are required to integrate their work into a coherent whole. Effective leadership is required both to bridge the gap between the disciplines that are involved and to overcome the additional barriers created by scientists working in different institutions and cultures. Perhaps the primary task is that of building trust between the various researchers involved. Achieving this requires a commitment to spend a reasonable amount of time together.
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