The promise of biotechnology in agriculture
Citation
CTA. 1996. The promise of biotechnology in agriculture. Spore 66. CTA, Wageningen, The Netherlands.
Permanent link to cite or share this item: http://hdl.handle.net/10568/47485
External link to download this item: http://collections.infocollections.org/ukedu/en/d/Jcta66e/
Abstract/Description
For twenty years, the development of biotechnology has given rise to great hopes and has stimulated considerable researcheffort throughout the world. Today, this effort is producing its first results in agriculture. Although still modest in...
Notes
For twenty years, the development of biotechnology has given rise to great hopes and has stimulated considerable research
effort throughout the world. Today, this effort is producing its first results in agriculture. Although still modest in comparison
with the prospects originally envisaged, these achievements should be of interest to both developing and developed countries.
No one can afford to ignore the major economic impact that the control and commercial exploitation of some biotechnological
procedures could have.
Taken in its widest sense, biotechnology encompasses any improvement that makes use of a biological process. Simple
examples in agriculture and food processing are brewing and the processing of milk, which have for centuries made use of living
organisms such as bacterial and moulds. Farmers, whose work has always been to improve and exploit natural processes,
often against considerable odds, could be thought of as the first biotechnologists.
Genetic engineering
Scientists prefer a more restricted definition of biotechnology. Plant biotechnology can be defined as comprising a range of new
methods which lead to varietal improvement, true reproduction and a very large number of individual plants which are exactly
the same as the improved parent variety. Even with this more focused definition, there are a great many research and
development programmes within the field of biotechnology. A study conducted in 1993 by IBS (Intermediary Biotechnology
Service) of ISNAR (International Service for National Agricultural Research) listed 216 separate activities, of which 75% were
devoted to plants and, of these, more than 40% were of direct interest to developing countries.
By using molecular markers to study plant and animal genetic diversity and genetic engineering to modify genetic inheritance,
new varieties can be created, which could not be achieved by natural means.
Enriched by genes introduced through Bacillus thuringiensis, a plant can be made toxic to insect pests. The same technology
can be used to make tobacco resistant to tobacco mosaic virus and to modify the composition of soya oil. In theory, the range
of possibilities is limitless. Some research teams are devoting considerable resources to surprising projects such as creating
varieties of banana, which when eaten will provide immunisation against hepatitis or cholera.
Given the resources and skills required for genetic engineering, research programmes are led by strong teams, which are
becoming increasingly international and collaborative. Some of the transgenic varieties which are of direct importance to many
ACP countries now on trial under glass include cotton, rice and cassava. Open field trials of such varieties are not without
potential risk. To date, only one variety of tomato and one of cotton, have been officially authorized for widespread cultivation
in the United States.
The ACP countries can often do little more than express an interest in the direction of international research. Nevertheless, it is
important that they should not lose interest in genetic engineering because of the prospects for true reproduction of plant
material, and it is this that will have the most impact on agricultural development. Professor Albert Sasson, Special Adviser to
the Director General of UNESCO, believes that 'Africa is, without doubt, the region where biotechnology is least developed.'
Even if this is true, ACP countries can take advantage of the many laboratory results obtained for temperate plants which are
often applicable to many tropical plants.
Overcoming nature's obstacles
The purpose of cloning is to reproduce from one plant a great number of progeny which are genetically identical to the parent.
This parent plant, a banana or a coffee variety for example, will have been chosen for particular performance characteristics
that meet the needs of growers.
Some plants, such as rice or cotton, are self-fertile and produce daughter plants that are practically identical to the mother plant
in performance. Others require cross fertilization between male and female plants of the same species. This is the case with
maize and the majority of the principal species of perennial plantation crops such as palm oil, robusta coffee, rubber or cocoa.
Progeny of plants that have been cross fertilized may not ' breed true. This is why farmers find that their yields of maize are
much lower when they sow seed saved from the previous year's c harvest of a high yielding hybrid.
Certain plants, like the cultivated banana, are sterile and cannot reproduce naturally except from side shoots. This hampers
varietal improvement by classical methods and limits the availability of good planting material. Biotechnology is opening the way
for micropropagation, meristem culture and, more recently, somatic embryogenesis in order to overcome these different
obstacles.
By making it possible to obtain plantlets from fragments of stem or shoot, micropropagation is no different in principle to
classical methods of propagation. In vitro propagation is more sophisticated than the techniques practiced by horticulturalists
and it has two distinct advantages: the ability both to produce many more offspring, and to ensure that the plantlets raised are
completely healthy. One parent plant can give rise to many hundreds of millions of identical plantlets which are free of viral
diseases. Costs of production depends on the level of handling required and this gives countries which have low salary
structures, such as those in the ACP regions, an advantage. Some ACP countries already have sizeable production units.
Focusing on flowers and bananas
In Kenya, where flowers are the third largest export crop after tea and coffee, the Kenya Agricultural Research Institute
(KARI) has developed in vitro cultivation of flowering plants. KARI has been working in collaboration with Oserian, one of the
three largest private horticultural companies in the country. The company has its own tissue culture laboratory, and since 1994
a staff of 54 people. Varieties are reproduced after being selected for productivity and resistance to pests. The company is
planning to commercialize its in vitro plant production for the Kenyan horticultural industry and for export. Côte d'Ivoire,
Zimbabwe and Mauritius (which has overtaken Hawaii in anthurium production) have also developed micro-propagation
facilities to service their own horticultural sector.
It is with bananas and plantains that these techniques have produced the most significant results for ACP countries. A private
company based in Santo Domingo, in the Dominican Republic, has developed commercial production of in vitro plants with the
support of the Centre for Research and Training in Tropical Agriculture for Central America and the Caribbean (CATIE) which
is based in Costa Rica. The company, Luoma Vitrolab, grew out of a family horticultural business and multiplies not only
bananas but also many ornamentals and aromatic plants.
In addition to its principal research activities, the Cameroon-based Regional Centre for Bananas and Plantains (CRBP) also
distributes in vitro plants of forty varieties that are used for local consumption. These are cultivated at its station in Njombe from
vegetative material supplied by INIBAP whose collections are kept in Leuven, Belgium. The plantlets are sent to a network of
development agencies and research centres, specifically in Gabon (AGRO Gabon, IGAD and CENAREST), in Congo (Agri
Congo, DGRST) and in the Central African Republic (ICRA). They are used for training technicians to harden the plants for
outdoor conditions and set them out in demonstration plots for farmers. By setting up this distribution chain to small producers,
the foundations are laid for promising future commercial production.
In some large plantation-holding companies, in vitro cultivation techniques has already grown to an industrial scale, particularly
in Africa. This has considerable significance in view of their agricultural and economic importance. In Abidjan, the Society for
the Study and Development of Bananas, a subsidiary of Terres Rouges, produces a million healthy, nematode-free plants each
year for its parent company Even if the distribution of these products to small-scale producers on the continent has yet to be
established, trade in in vitro plants is becoming the focus of major international producers. Tropitec, a private company in South
Africa, has a commercial agreement to multiply plantain hybrids which are supplied from Honduras by the Honduran
Foundation for Agricultural Research. Millions of plantains are then returned in test tubes by air to Honduras where Tropitec
has a specialized unit for hardening off the in vitro plants ready for commercial production throughout tropical Latin America.
Uganda's test-tube coffee
Uganda is the second largest producer of robusta coffee in Africa after Côte d'Ivoire. At the beginning of 1996, a laboratory
for in vitro cultivation was established within the Farming Systems Programme, a national programme funded by the KU. One
activity of the programme is to replant old coffee trees with higher yielding varieties that are resistant to rust. This medium-sized
production unit, which was established within the Institute of Agricultural Research in Kawanda with the technical support of
CIRAD, has the capacity to prepare a million micro-propagated coffee plants per year, with a staff of only six. After the initial
start-up phase, production will be targeted towards the country's 1.2 million small-scale coffee growers. These growers, who
make up 7.5% of the population, grow 250,000 hectares of coffee, which in 1990 brought in 79% of Uganda's export
earnings.
The Kawanda laboratory will strengthen the Institute of Agricultural Research's traditional nursery, which currently produces
several thousand clones each year. These are distributed to propagation units which then multiply them for onward sale to
producers. The capacity of this classical horticultural propagation system is far below that required for the Uganda programme,
which envisages the replacement of every coffee tree in the country. Given that 2,000 plants are required per hectare, the new
laboratory will be able to meet only a small proportion of the demand. It seems likely that private companies will eventually
take on this work, therefore the laboratory is already diversifying into meristem culture of local varieties of bananas. Work on
cassava may follow.
With an annual operational budget of US$150,000, the Kawanda laboratory can produce 500,000 in vitro plants of coffee per
year and as many banana plants. Smallscale growers currently pay US 50 cents (US$ 0.5) for a traditionally raised robusta
plant. The difference in price allows for marketing costs and a profit on the work of hardening off the in vitro plants: work
which a farmer, once trained, can easily master.
Back to the future
Research is currently well advanced in the technique of cloning by somatic embryogenesis which is far more powerful in terms
of productivity than micropropagation. This technique, for example with leaves, consists of taking back differentiated,
non-reproductive cells to an undifferentiated state, so that they can each develop as a complete individual plant, genetically
identical to the parent. Somatic embryogenesis requires the use of complex hormones and is particularly well adapted for
cloning some species, like oil palm, where other in vitro propagation techniques are impractical.
Experiments are usually undertaken by collaboration between universities and the major European research centres. Field trials
are currently taking place in order to check that each developing plant conforms to type, and particularly to fruit formation. A
consortium of agro-processing companies is quietly conducting trials in Brazil and Ecuador of several thousand arabica coffee
trees propagated by somatic embryogenesis. To date there appear to be no problems with conformity. Oil palm produced by
the same technique is proving equally satisfactory. A research team of scientists drawn from ORSTOM and CIRAD have
conducted field trials in Côte d'Ivoire for several years and appear to have achieved a potential productivity gain in the order of
15% to 20%. This has also been observed in Indonesia and Malaysia. Having had their fingers burnt in the past by too hasty
forays into industrialization, the scientists will remain cautious for a few more years. But there can be hardly any doubt that
somatic embryogenesis is an essential technique for multiplying, and therefore adding value to varieties Improved by genetic
engineering.
Weak commercial management
Many attempts to transfer and adapt technologies in the past, particularly in West Africa, have had no impact beyond that of
training scientists and laboratory technicians, although this is not an insignificant achievement in itself. Some of the technologies
involved species for which there was no real market. However, research efforts on varieties of major economic importance are
beginning to give biotechnology its first significant developments in some ACP countries.
Technology and production costs are no longer always the limiting factor to using biotechnology. This has been shown by the
experience of large plantation-owning companies and by the intensive floricultural export industry. However, it is also true that
the absence of commercial management know-how at the heart of publicly-owned production facilities still restricts the
distribution of the products of biotechnology to scattered markets in the villages. As with many other agricultural inputs, it
would appear that without the necessary marketing strategy, any attempt within the public sector to adopt new technologies,
however sound will always remain a risk.
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