The BCCCA have had a long commitment to the improvement of the cocoa crop and undertook to hold a meeting of scientists involved in molecular characterisation of cocoa germplasm. The objectives of this colloquium were for interested scientists to share results, co-ordinate projects, and work towards a vision of a world-wide cocoa enhanced breeding programme. The colloquium was held at CIRAD on the 21st September 2000 and was attended by approximately 30 scientists. Presentations were made by BCCCA, CRU Trinidad, the University of Reading, USDA, CIRAD, and the ICGD, followed by open discussions on the future of gerrnplasm characterisation using molecular tools. The cofloquium participants agreed the foliowing:
These conclusions will be described in more detail and how molecular characterisation fits into a world-wide cocoa breeding programme enhanced by molecular tools will be discussed.
Introduction
The BCCCA Cocoa Research Strategy
Collecting, conservation, characterisation, cataloguing and distribution
Colloquium programme and format
About 30 participants, mainly scientists from research institutions directly involved in
the subject, attended the colloquium. Speakers were:
The chairman of the BCCCA Cocoa Research Committee introduced the topic of molecular characterisation using a real-life example of an area of confusion: several versions of SCA 6, which are phenotypically distinct from each other, appear to exist. The colloquium goals were described: an informal exchange of information, a description of the potential methodologies, identification of the areas of compatibility, a draft plan agreed of a global characterisation programme, and a clear recognition of the need for data capture and dissemination.
The role of molecular biology techniques in a world-wide cocoa enhanced breeding programme was described, and the point was made that this colloquium was only considering the topic of molecular characterisation (future meetings may focus on other molecular biology tools and their use in cocoa improvement). Several more examples were presented of cases where there was a real need for unequivocal characterisation of cocoa germplasm. Real life examples were also described of attempts to characterise germplasm at CRU Trinidad, University of Reading, USDA Beltsville, and CIRAD Montpellier, using a variety of techniques. Finally in the presentation session, the extremely important issue of information management in cocoa characterization was discussed and suggestions were made as to how this could be incorporated into the International Cocoa Germplasm Database (ICGD).
The remainder of the colloquium took the format of an open discussion facilitated by BCCCA in which the technology, gaps, agreed needs, and future steps were openly discussed by all participants. At the end of the day, approximately 30 points had been captured and these were subsequently sent by email to participants for their approval. The following are the agreed points from the BCCCA Research Colloquium I, grouped into themes:
Agreed outputs grouped under themes
(numbered as they came up during the colloquium)
General strategy
Linking collections and quarantine facilities to germplasm characterisation
Recommendations on molecular tools for germplasm characterisation
Additional experiments needed for a robust molecular approach to germplasm characterisation
Database management in germplasm characterisation
Discussion and future prospects
General strategy
Linking collections and quarantine facilities to germplasm characterisation
Recommendations on molecular tools for germplasm characterisation
Additional experiments needed for a robust molecular approach to germplasm characterisation
Database management in germplasm characterisation
Molecular characterisation as part of a world-wide cocoa enhanced breeding programme
Acknowledgements
The BCCCA would like to thank the speakers, the participants, and our hosts CIRAD for making the first BCCCA research colloquium a success.
Biotech Glossary |
Bioinformatics |
Lab Protocol |
Notes |
Malaysia University |
A Report on BCCCA Cocoa Research Colloquium I:“Germplasm Characterisation Using Molecular Tools”
Martin Gilmour
Mars Confectionery, Dundee Road, Slough, SL1 4JX, United Kingdom
Currently, small farmers grow most of the world’s cocoa and research is urgently needed to help them produce good quality cocoa using sustainable growing systems. The UK cocoa and chocolate industry represented by the Biscuit, Cake, Chocolate and Confectionery Alliance (BCCCA) has a long tradition of support for cocoa research both in the UK and in producing countries. To safeguard the future of the cocoa and chocolate industry, there is a need to ensure sustainable supplies of good quality cocoa at prices which provide a worthwhile return to all those involved in the cocoa chain, from grower through to chocolate manufacturer.
On a world-wide basis, the ultimate aim is to develop and make available cocoa trees suitable for each region, having the following characteristics: high yield, early bearing, resistance/tolerance to major relevant pests and diseases, cocoas of good quality and flavour, low maintenance and production costs, and environmental sustainability. In addition, there is a need to develop the knowledge and expertise to control pests and diseases that may arise in the future, in a way that fits with integrated crop management principles.
Cf early, this task is beyond the resources, which the manufacturing ndustty is able to make available, and additional support must be obtained. However, two strategies are possible whereby manufacturers may be directly involved. Firstly, by providing assistance which will enable plant breeders in the producing countries to develop the improved tree stocks which are needed. Secondly, by sponsoring research into the control of pests and diseases and farming production practices in the major producing countries. Ideally, both of these objectives need to be achieved using no pesticides or by minimal usage in a system of Integrated Pest Management.
The single most important route for effecting improvements in the efficiency of cocoa production will be through plant breeding. Breeders need germplasm containing sufficient diversity to allow them to produce varieties with good economic characteristics, which will perform well under local environmental conditions and pest and disease pressures. Their progress will be accelerated if they have access to information on the characteristics of the material, are confident of its identity (perhaps through molecular characterisation), and if they can exchange material with other genebanks via intermediate quarantine to minimise the risk of spreading pests and diseases. Research needs are:
Given the level of interest shown in the colloquium it came as no surprise to find that the participants were in complete agreement that the overall objective of unequivocal characterisation of cocoa germplasm was an essential and worthwhile goal. In the longer term, there is a clear need for a global co-ordinated programme, but the USDA project to characterise the cocoa germplasm in the Americas represents a very good start. A future output of this work could be the definition of a ‘virtual collection” of cocoa germplasm, defined genetically, spanning the known genetic diversity of the species, but not necessarily geographically located at one site.
The current collections of cocoa germplasm are clearly the first place to start on any world-wide cocoa characterisation programme. There was broad agreement that in characterisation work, type specimens should be identified by people who have close knowledge of the collections and specific varieties of cocoa. The simple but vital aspect of tagging these type trees should be done in a robust, durable way. The subject of how to deal with off-types generated a lot of debate, but apart from recognising that this was a major issue, the colloquium did not attempt to propose a solution. It would perhaps be appropriate to place the responsibility for dealing with off-types with the individual curators of the collections. As the cocoa research community moves towards a world-wide cocoa molecular characterisation programme, there is an expectation that primary genebanks will share results and germplasm. Although this is potentially a politically sensitive issue, it needs to be stated that it remains the expectation of the research community that there should be free exchange of results and germplasm between collections. This needs to be done in a way which takes into account the potential spread of cocoa diseases, therefore it was noted in the colloquium that The University of Reading Intermediate Quarantine facility is currently the only centre able to forward cocoa germplasm to all cocoa producing countries.
It was not surprising given the high level of existing work in this field, that there was a lot of debate on the techniques currently used in cocoa molecular characterisation. It was more surprising that some clear recommendations emerged as to the way forward - the use of microsatellites, the number of microsatellites needed for fingerprinting (15), the estimated throughput, the preference to avoid radioactivity, etc.
A feature of the colloquium was the planning of future, usually collaborative experiments, which would take the research community closer to a global cocoa characterisation programme. More experiments were planned to distinguish mutations from off-types to look at pooling samples for greater throughput (especially for collections like that in Trinidad where multiple copies of single genotypes are kept), to set up an inter-laboratory ringtest. and to determine if fingerprinting could distinguish between sibs.
The colloquium debate was mainly restricted to the above issues and practical aspects of applying molecular biology techniques to cocoa germplasm characterisation. It became clear during the meeting that this was only part of the bigger picture, and that the issue of how to record, integrate, and share the voluminous data likely to be generated by molecular characterisation was a major unfilled gap in resources. This was emphasised by the desire of the colloquium participants to have the largest range
of data stored and made available to the research community. A few recommendations were made such as to use existing models of plant genetic databases, to try and link the data to the ICGD, and to start recording molecular data leaving phenotypic data for the future. The colloquium concluded that the need for a specialised bioinformatics person was clear, and the need for funding of such a person was a priority.
The BCCCA sees the molecular characterisation of cocoa germplasm as part of a larger programme to modernise the cocoa crop. Secure, diverse, characterised collections of cocoa germplasm form a platform for breeders, agronomists, pathologists, ecologists, physiologists, molecular biologists, and biotechnologists to work on known accessions of cocoa, safe in the knowledge that their results will be internationally comparable. This work also underpins the setting up of mapping populations for the identification of QTLs, and the development of marker-assisted selection schemes. Gene discovery programmes using EST technology, or candidate gene approaches also rely on the unequivocal identification of germplasm. These modern molecular breeding techniques and molecular characterisation in combination with conventional breeding, will lead to the development of elite trees which can be propagated by a variety of new tissue culture and horticultural methods. It is not an exaggeration to say that the outputs from this colloquium are at the heart of improving the cocoa crop for growers and consumers around the world. Therefore in conclusion, as well as the above outputs and action points, the unequivocal message from the first BCCCA Research Colloquium is that molecular characterisation has a vital role to play in a world-wide cocoa breeding programme enhanced by molecular tools.