Luxembourg, 26 – 30 June 1989
The above Symposium, organized by FAO in collaboration with the European Economic Community in Luxembourg in June 1989, reviewed the current status of plant biotechnologies with special reference to the needs of developing countries; appraised the socio-economic impact of new technologies in the fields of food and agriculture; and identified activities that should be promoted by the international community.
A limited number of experts were invited to the meeting, which in addition to holding a plenary session, examined problems and potentials to various groups of crops. The report of Working Group 4, dealing with fruit trees, palms, multi-purpose trees, coffee, tea and cocoa, is reproduced below.
Dr. F.T. Ledig of USA chaired Workshop 4; Ms. C. Palmberg of FAO's Forestry Department acted as Rapporteur. It was attended by some 40 scientists, of whom somewhat over one-half were from developing countries.
REPORT OF WORKSHOP 4
INTRODUCTION
Workshop 4 examined the state of the art, progress and general issues in biotechnology related to fruit trees, palms, multipurpose trees, coffee, tea and cocoa. In addition to six invited background papers, nine brief presentations on various crops were made as a basis for discussion.
STATE OF THE ART
It was noted that although heterogeneous as far as biology, variation, present-day knowledge and traditional management strategies are concerned, the crops included were all perennial and long-lived organisms. Therefore, their conservation, breeding and improvement faced a series of common problems and joint efforts for solving these were feasible and desirable. New biotechnologies complement traditional breeding methodologies in the development of priority species and provide an additional and at times very precise tool in reaching specified goals.
Methodologies used to date include tissue and organ culture, somatic embryogenesis and micrografting used to rejuvenate tissue, for rapid multiplication of valuable genotypes and, in the case of e.g. palms and coffee, also applied as a tool in genetic improvement and in the production of routine planting stock (albeit with some problems in genetic stability of the material produced). In all these fields, the necessity for adequate field testing of materials produced will delay practical application by several years. Examples of large-scale failures due to inadequate testing of e.g. tissue-cultured oil palm, were cited as a warning.
To date tissue culture has not always been focussed on specific, identified problems, and has frequently been isolated from overall breeding strategies of which it should form an integral part. However, efforts have not been wasted. They have familiarized scientists with existing techniques, and have served to identify options that may have value when incorporated in a complete package for the improvement of perennial crops.
Attempts have been made to develop methods for early screening for tolerance/resistance to pathogens and environmental stress using in vitro cultures. However, it is not yet clear whether these have been successful in producing field-level resistance, and further testing and refinement of technologies is needed.
Propagation of meristematic tissue and shoot tip grafting in vitro for the production of disease and virus free materials, have been successfully applied especially in citrus and other fruit trees. The use of monoclonal and polyclonal antibodies in early disease detection has found application into practice in a number of tree crops. Zygotic embryo-culture has been developed for the exchange of germplasm in coconut.
Isozyme electrophoresis has been used as a tool for characterizing the amounts and distribution of genetic variation especially in forest tree species, as a basis for development of sound breeding strategies and in genetic conservation schemes. Considerable efforts have been made in the field of enhancement of nitrogen-fixation in woody perennials.
Work on the production of haploids and di-haploids, somatic embryogenesis, exploitation of somaclonal variation and somaclonal hybridization, has been carried out on an experimental scale in many crops.
Protoplast fusion, gene cloning, gene transfer and recombinant DNA technology are in the early stages of development, and dependent on a fuller understanding of the genome of target species and of gene action. Some advances have been made in the development of restriction fragment length polymorphism mapping in a few species, however, it is predicted that many decades are needed before potential economic benefits from these methodologies can be realized.
In summary, few techniques which have been developed and refinded in the laboratory, have been applied at large scale or helped solve specific problems. Those which to date have had some impact or have a potential for early, large-scale application, include the use of tissue culture for early screening for disease and stress resistance, as well as for rejuvenation of mature materials and the mass-production of valuable genotypes for further breeding and for conservation purposes. They also include isozyme techniques in the determination of genetic variation and genetic distances as a basis for breeding and conservation, the use of monoclonal antibodies in disease detection, and the use of tissue and zygotic embryo-cultures to overcome problems posed by quarantine restrictions in the exchange and transfer of genetic materials. Meristem culture has been successfully applied in the production of disease-free materials in vegetatively propagated crops. Biotechnologies have also proven their value in the field of biological pest control, and have helped gain a better understanding of the processes involved in biological nitrogen fixation.
IDENTIFICATION OF PROBLEMS AND PRIORITIES
The relatively long time scale needed from the time a new cultivar or variety is developed to the time it can be brought into large-scale production, and the lack of familiarity of politicians and decision makers with the potential of the new biotechnologies, coupled with the over-all scarcity of funds and the needs to solve a range of urgent problems, often render financing of research inadequate and insecure in the longer term.
Efforts in biotechnology in palms and tree crops should be focussed on increasing production, quality, disease and stress resistance in the species concerned, and on facilitating interchange of genetic materials and supplementing genetic conservation efforts. As a basis for this, a better understanding of plant physiology, molecular biology and biochemistry is needed.
The workshop recognized that the complexity of problems cannot be solved by the new tools provided by biotechnologies alone, but that a combination of traditional and new technologies was needed.
Different crops, and different characteristics targeted for improvement within a crop, will require varying levels of intensity of intervention. The intensity of intervention is also correlated with the socioeconomic importance of the crop, the scale of planting and the possibilities to control and modify the environment in which the plants are grown.
There is an urgent need to increase crop production, however, this poses a range of problems in long-lived perennial plants, particularly when the infrastructure for breeding is not always in place. The need to shorten the time to get new materials into field production was felt by most participants in the Workshop. Selection followed by rapid multiplication of superior clones through conventional vegetative propagation or tissue culture, is a way to accomplish this. However, it is fraught with risk unless clones are adequately tested. It is also important to acknowledge that sexual reproduction will have to be used in the development of new materials for selection and use in the medium and long term. The development of improved genetic materials is a continuing process rather than a one-time effort.
Sustainability of a crop and its breeding, are dependent on genetic variation. In many crops, including forest trees, a large amount of natural variation is still available. New biotechnologies have helped bridge barriers between species and will facilitate the transfer and use of beneficial genes and gene complexes. They have thus given an added value to existing variation and to each potentially useful gene. It is of maximum importance to explore, evaluate and conserve existing genetic variation in all crops and species of actual or potential agricultural value, using both in situ and ex situ methodologies; these latter ones may include, as an important component, the conservation as tissue to complement ex situ conservation as seed, pollen and live collections. Short-term breeding strategies must always be complemented by long term strategies, which give due consideration to the maintenance of a broad genetic base and flexibility allowing for incorporation of new findings and/or end use requirements into the programme. Proper and sustainable use of our global heritage of genetic resources will require a strengthening of international agreements and schemes.
In the breeding for increased productivity and quality in plants, saturated linkage maps, based on restriction fragment length polymorhisms (RFLPs) have great potential to reduce the element of chance in breeding. In the next few decades the ease of assembling such maps is likely to increase, rendering this methodology of practical value in a larger range of crops and countries than is presently the case. New genes may also be isolated that will be of value, e.g. the cytokinin gene (isopentyl transferase) for improved shoot proliferation, which would greatly assist breeding efforts in e.g. tea. Mechanisms should be established that enable developing country scientists to become conversant with the expanding technologies so they can appropriate them when ready, and further develop them for local use.
Exchange of germplasm is an imperative in crop improvement. In addition to some present restrictions in the free availability of a few specific crops, it is hindered by lack of availability of reproductive materials and the absence of an exchange network between institutes in many multipurpose trees and other perennial crops. Furthermore, quarantine restrictions constitute a de facto barrier between many countries. Regarding this latter point, tissue culture can be used to produce and transport pest-free materials complemented by the development of monoclonal and polyclonal antibody technologies to ensure that diseases are not present in material exchanged (e.g. citrus, date palm). Micrografting using plantlets germinated in vitro from seed and the grafting of somatic embryos, will permit the regeneration of complete plants (e.g. cocoa at CATIE, Costa Rica). This technique will go on a long way to promote and help germplasm exchange and improvement.
Disease and pest resistance is an identified problem in virtually all perennial crops. Three approaches to the problem were suggested:
Research is needed on new screening techniques to assess and select for resistance or tolerance at early stages, even in tissue or cell culture;
cross-resistance could be sought;
biotechnology could be used to develop more effective predators or diseases of insect pests.
The production of food, fuel, fodder and fiber often entails growing hardy perennial crops in areas marginal to plant growth, including alkaline, saline, droughty and cold sites. It is intrinsically difficult to select for tolerance for such environmental conditions. A combination of conventional and somaclonal selection methods may assist in this task. In all cases it is fundamentally important to base the application of new biotechnologies on a sound understanding of the physiology and biology of a species, and to ensure maximum linkages with traditional plant breeding methodologies which they complement but cannot substitute. As it is also known that the management of a crop will decisively influence its growth and performance, appropriate linkages must be made between breeding and crop management, and limiting factors in the complete production chain from establishment to harvesting must be identified and resolved.
Certain forest species of present-day value such as rattan (Calamus spp.) some tropical timber species and some medicinal plants, have over the past years been heavily utilized without proper concern for maintenance of the resource base through management of existing populations to ensure their sustainability. Early action is needed, using all available methodologies, to regenerate such species to meet prevailing needs, while at the same time conserving existing variation for future use. Biotechnologies coupled with traditional methods, can help meet this dual objective through providing a rapid means of immediate production of genetic materials for planting, as well as for ex situ conservation to support on-site gene management.
Perennial tree crops provide a range of goods and services, including oils, gums, resins, tannins, dyes, flavourings and medicines. Enhancement of production of non-wood products through conventional methods and biotechnologies is an urgent need, which can help maximize per unit area production of presently marginally economic crops, promote socioeconomic development in rural areas, and help minimize potential negative effects brought about by attempts at product-substitution by industrialized countries. The need exists for studies on the biology and genetic structure of these species. Isozymes are one way of rapidly assaying their genetic variation. Genetic conservation programmes must also receive high priority so that options are left open for possible future changes in market demands and breeding requirements.
Fermentation techniques and enzyme technology for the modification or elimination of waste products originating from production systems using perennial crops, should receive high priority.
INFRASTRUCTURE AND HUMAN RESOURCE REQUIREMENTS
Developing countries suffer from lack of infrastructure (including facilities for repair and maintenance of equipment), equipment (including chemical reagents), access to information, and cadres of specialized, interdisciplinary teams of scientists conversant with the new technologies. This is in many countries compounded by scarcity of scientists and researchers working in traditional improvement and breeding schemes; and lack of linkages and collaboration between these two groups.
The development and maintenance of appropriate infrastructures for research and application of new technologies will have to be tackled at both national and subregional/regional levels. Whereas many problems are site-specific and should therefore be handled nationally, there are given fields of research which require sophisticated and expensive equipment, which may best be tackled regionally. Existing national and regional institutions should be strengthened to carry out work, rather than embarking on the establishment of new ones.
Information transfer between industrialized and developed countries, as well as among developing countries themselves, needs to be strengthened and promoted. Important texts and reports should be made accessible in a range of languages to facilitate their dissemination and use. Developing country scientists must be provided better access to journals and particularly database accession. Exchange visits between scientists in developing countries should also be promoted to allow the transfer of know-how and to help avoid duplication of effort.
The lack of career development possibilities in research often leads to rapid turnover of research staff and, consequently, a lack of continuity in medium and long-term research. This “brain drain” is compounded by un-met expectations in students, who on return from training abroad may find existing facilities so limited as to constitute a barrier to application even of less sophisticated techniques. A component of funds for purchase of equipment should be built into training fellowships in industrialized countries.
Training in industrialized countries may, at times, remove students from contact with research problems in developing countries. Furthermore, students are often channelled to currently more glamorous areas of science, such as biotechnologies, without concern for the possible inadequacy in staff trained in conventional breeding. To maximize the benefits of training, national and regional planning is necessary. The first step is to identify specific problems and problem areas and, on the basis of this determine the type of training needed.
Many students who return are siphoned off into administration, due to an over-all lack of qualified personnel. Some guarantees are needed that opportunities of work will be offered to the student in his/her area of specialization upon return.
Trained personnel is needed at all levels, from the scientist to the laboratory assistant and field technician. In the rapidly developing field of biotechnology, refresher training and easy access to information is of fundamental importance.
National centres can be considerably strengthened by ensuring interdisciplinary, in-country collaboration between existing institutions, including Universities. Contractual services may be required to fully involve e.g. Science Departments in assisting in problem-oriented biotechnology, as applied to agriculture. Close ties between private biotechnology companies and university scientists in industrialized countries has contributed to the rapid application of new methods, and such linkages may hold some promise also in developing countries.
Two-way contact between up-stream research teams and field personnel, bridged by adequate extension services, is extremely important to ensure that research effectively assists in the solving of priority problems.
The raising of awareness at the level of politicians and decision-makers is an important prerequisite to ensure the necessary medium and long-term commitment which building up and maintaining adequate scientific skills and facilities requires. The holding of international symposia and meetings like the present one in developing countries and involving politicians and decision-makers in parts of the discussions, would help in this respect.
ROLE OF ASSISTANCE; ACTIVITIES AND PROGRAMMES
The main role of international assistance schemes is to help develop national capabilities (including infrastructure and equipment); and to assist in the training of personnel and the exchange of information and genetic materials. Training can be carried out either in another country, in which case return visits of the trainee are likely to be needed at regular intervals; or in-country training can be arranged through twinning arrangements or the development of externally aided, government requested projects focussed on research, with equipment, training and exchange of scientists as main components.
To facilitate the formation of national scientific teams, in-country training courses and workshops should be sponsored, in which tissue culture groups, biochemical genetics groups, horticulturists, forest and agricultural geneticists etc. are brought together to discuss important development problems and their solution, using a multidisciplinary approach. Training is also needed at the level of the laboratory and field technician.
Regional and sub-regional workshops and training courses can fill important gaps in exchange of information and know-how, and help establish contacts between scientists and institutions. Several agencies and institutes are already involved in supporting such activities, which should be strengthened to meet increasing needs.
External assistance is urgently needed in the exchange of information. This may include electronic communication through existing networks, where feasible; and funding for the prescription of scientific journals and books. Support to consultancy services to solve specific technical or scientific problems, is also needed.
A major role of international agencies is assistance in networking. A number of successful models exist of networks in other, related fields. Networks should be well-focussed, address specific problem areas of high, over-all priority and cover fields in which some national know-how and programmes already exist. Outside funding to cover coordination, information exchange (including newsletters), exchange visits of scientists and the arrangement of workshops and seminars, is needed in the creation of successful networks.
A need to more efficiently disseminate information on existing programmes supporting research and training in developing countries, such as those of International Union of Biological Sciences, STD2 (EEC) and the Commonwealth Science Council, became apparent during the discussions. The role of UN agencies was acknowledged to fill a gap thanks to their non-political nature.
At the end of the Workshop, participants contributed to the chair their ideas on priority programmes needing international assistance. These are reflected in the above paragraphs, as well as in the individual workshop papers on coffee and cocoa; tea; oil palm; date palm; citrus; and forest trees, reproduced in the present proceedings.
