E L S E V I E R

Biotechnology Advances, Vol. 15. No. 2, pp. 333--352, 1997 Copyright © 1997 Elsevie~ Science Inc. Printed in the USA. All rights resexved

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C O C O A B I O T E C H N O L O G Y : STAT U S, C O N S T R A I N T S A N D

F U T U R E P R O S P E C T S

NIKOLAUS GOTSCH

Institute of Agricultural Policy and Market Research, Justus-Liebig-University Giessen, Senckenbergstrasse 3, D-35390 Giessen, Germany and

Institute of Agricultural Economics, Swiss Federal Institute of Technology (ETH), ETH Zentrum, CH-8092 Zurich, Switzerland

ABSTRACT

Current status and future prospects of cocoa biotechnology are reviewed. Potential for improving and

modifying cocoa bean yield and quality are discussed. Prospects for producing cocoa components m vitro

and cocoa butter substitutes in crops other than cocoa are examined. Application of complementary

research tools is expected to allow significant enhancements in cocoa bean yield. Furthermore, cocoa

varieties with modified characteristics are likely to become available, in particular varieties with increased

cocoa butter content and modified fatty acid patterns. In vitro production of cocoa components is less

likely. © 1997 Elsevi~ Science Ine,

Key words: Theobroma cacao; cocoa; cocoa butter substitute; Delphi survey.

INTRODUCTION

Agricultural exports are significant contributors to income of developing countries. About 11% of the

total export value of those countries originates from agricultural products [3, 11]. For specific

commodities, the contribution of agricultural exports becomes even more significant. For example, cocoa

contributed 29 % to the total Ghanaian export earnings for the years 1991-93 [3]. As a general rule, the

impact of biotechnology on international trade of developing regions is most likely through its impact on

agriculture. For cocoa, the most recent comprehensive study on the status and constraints of production

and research was published in 1985 [8]. This review focuses on the present status, constraints and

potential of cocoa research and development. A perspective is presented on the future of characterization,

improvement and use of cocoa germplasm, the chances of improving cocoa bean yield and modifying

333

334 N. GOTSCH

cocoa quality, and the likelihood for producing cocoa components in vitro or cocoa substitutes in

engineered crops other than cocoa.

For the purposes of this review, agricultural biotechnology is interpreted in a broad sense [1],

including modem biotechnology, genetic engineering, and the whole range of tools, agents and

knowledge that influence the productivity of crop plants.

REVIEW SURVEY METHODOLOGY AND PARTICIPATION

This perspective on future developments is focused on a time horizon often to 25 years. Such long-range

forecasts must allow for discontinuities caused by innovations; hence, reliance on expert intuition is

inevitable. One intuition-based research method is the Delphi method that was first described by Helmer

and Rescher [6]. The Delphi method was designed to elicit group opinions from a set of experts with the

help of written questionnaires. An important reason for use of expert opinion is the lack of any historical

data applicable to future technology. The questionnaires not only ask questions, but also provide the

group members with information about the degree of group consensus and the arguments presented by

the group members for and against various positions. For a more detailed discussion of the survey

methodology see Gotsch [5]. The survey discussed here consisted of three rounds. Round one gathered

information on cocoa research activities, prospects and constraints, but did not include quantitative

forecasts. The results of this first round are presented in the following section.

The exact course of the future development of a technology depends on external social, political,

legal, and economic conditions, which may vary considerably over long periods. To account for this,

three different environments or scenarios were formulated. Those scenarios served as a basis for the

experts' forecasts in the second and third rounds of the investigation. The elements used in the scenarios

were identified by the experts in the first round. In the 'business-as-usual' scenario, historical trends and

developments continued into the future. Forces that shaped the past continued to evolve. A second

scenario, the 'improvement' scenario, included factors more favorable to cocoa research and development

and the economic and social environment than those under the 'business-as-usual' scenario. A third

'breakdown' scenario allowed for less favorable than those under the 'business-as-usual' scenario. For a

more detailed description of the scenarios see Gotsch [5].

In the second and third rounds of the survey, the experts quantitatively assessed the possible impact

of specific techniques and technical developments by assigning a weighting between zero and 100. Zero

COCOA BIOTECHNOLOGY 335

indicated no prospect that the issue investigated will successfully develop within the scenario and the time

horizon given, whereas 100 indicated complete agreement with the possibility.

The quantitative assessments of the experts were analyzed with the help of descriptive statistics. For

this purpose the median M and the quartile-limiting factors Q 1 and Q3 were obtained by arranging the

experts' answers in descending order and subdividing them into four equal parts (quartiles). The value

between the first and the second quartile was the first quartile-limiting factor Q1, and that between the

third and the fourth quartile was the third quartile-limiting factor Q3. One quarter of the experts assessing

a specific statement estimate a value less than QI. Another quarter of the participants assessing a specific

statement estimate a value greater than Q3. Half of the experts estimate a value between Q1 and Q3,

which is called the interquartile range. The central value is the median M. The median divides the answers

into two equal parts.

The questionnaire of the first round was sent in December 1994 to 92 experts from 23 countries.

Those 48 experts from 16 countries who returned a completed questionnaire in the first round or

expressed their opinions in personal letters received the questionnaire in the second and the third rounds.

Of the 29 questionnaires submitted in the third round, those of 27 experts from 14 countries were

completed correctly and thus included in the forecasts presented in this article.

STATUS, CONSTRAINTS AND POTENTIAL OF CURRENT COCOA

RESEARCH AND DEVELOPMENT

This section is based on the information provided by the experts in the first round of the survey. Their

statements allowed a systematic presentation of the factors and forces influencing cocoa research and

development (R&D). These are discussed with the help of Figure 1. Our analysis starts with the box

'Output' (Figure 1). A primary driving force for research and technical progress is inadequate output of

production systems and also technological shortcomings of the inputs required to obtain this output.

Output must be understood in a comprehensive way, including not only the quantity and quality of the

requested products, but also the undesirable side-effects (e.g., ecological damage) of production.

These inadequacies lead to re-formulation of the 'Goals for applied R&D.' Some specific research

and development goals (Figure 1) are:

* Reducing yield losses caused by diseases, pests, and environmental stress.

• Improving crop quality with respect to: flavor (alkaloids (theobromine contents) and protein

storage), plant lipid biochemistry and biosynthesis (total butter production), fatty acid

336 N. GOTSCH

T

T \ App, 1

T R&D J~

5 Goals for ~') intermediary /

R&D J

1

Figure 1. Interactions between cocoa production, research, and inputs.

composition, morphological characteristics (bean size), pesticide residues and heavy metal

contamination.

• Improving crop production systems by: reducing requirements for non-renewable inputs per

hectare (pesticides, fertilizer); reducing land and labor requirements; providing modified planting,

pruning and rehabilitation systems (planting of different resistant lines, optimized canopy

architecture to reduce water stress or disease and pest attack); reducing environmental pollution

and degradation caused by cocoa production (pesticide contamination and soil degradation,

deforestation of primary forests).

• Improving nutrient assimilation capacity, availability and partitioning.

• Increasing yield.

'Applied R&D' (Figure 1, third box) provides improved inputs and refined methodologies for the

application of newly developed and already existing inputs. Included are:

• Practical crop breeding (to improve resistance to diseases and pest, and environmental stress; to

enhance quality and yield; to promote precocity and to improve management characteristics of the

trees)

• Disease and pest control: biological and microbial control; methods for integrated management of

diseases and pests

• Epidemiology

COCOA BIOTECHNOLOGY 337

• Plant pathology and agricultural entomology for the screening of the host range and pathogenicity

and the analysis of host-pathogen interactions

• Crop physiology to investigate yield and quality formation

• Agronomy to improve cropping systems, crop rehabilitation, and replanting

• Crop system analysis and modeling.

As a result of research, improved 'Inputs' (Figure 1) such as new planting materials and pesticides

may be available to produce more of the desired outputs. To improve efficiency and consequently the

output of the production system, it may be necessary to fulfill certain 'Goals for intermediary R&D'

(Figure 1) which are:

• Better knowledge and understanding of the cocoa crop

• Improved practical crop breeding providing systematically improved selection criteria; and faster,

earlier and more efficient field selection

• Faster planting material multiplication and production

• Conservation of genetic resources

• Improved knowledge and understanding of diseases and pests.

These intermediary goals are not new. But recent technological innovation has provided tools that

allow the development of'Intermediary R&D' (Figure 1). Intermediary R&D includes:

• Cocoa germplasm characterization, conservation, and management

- with the help of the complete plant or parts of it (morphological characterization using

botanical descriptors; agronomic and technological characterization and evaluation; database

management including electronic documentation)

- using biochemical markers and molecular marker technology

• Genetic characterization of the pathogens using molecular marker technology

• I n v i t r o techniques: plant regeneration and micropropagation, germplasm preservation and

conservation.

• Genetic engineering.

The following section details the status and potential of the intermediary tools. This is followed by an

analysis of the role and prospects of the applied tools and an overview of factors constraining cocoa

research.

338 N. GOTSCH

Intermediary Research and Development

General aspects. Methods of intermediary research and development provide better knowledge of the

crop with respect to its genetic, physiological and breeding characteristics, and disclose biological,

physiological, technological, phytopathological and agronomic characteristics. Furthermore, they assist

the systematic improvement of practical crop breeding, providing refined criteria for the selection of

crossparents in the breeding process, and a more efficient and faster selection of clones with valuable

characteristics followed by an accelerated propagation of planting material from these clones.

The importance given to the improvement of intermediary R&D could be seen from the fact that

57 % of the participating experts described research projects developing one or several of these

methodologies. Many institutions--mainly publicly financed large bodies--were simultaneously active in

several fields, including cocoa germplasm characterization, conservation, and management, genetic

characterization, and in vitro techniques. From the experts' answers the importance of the various

research goals in the development of intermediary R&D was assessed and the following were identified as

especially important: better knowledge and understanding of the cocoa crop; improved practical crop

breeding for faster, earlier and more efficient field selection; and systematically improved selection

criteria.

Cocoa germplasm characterization, conservation and management. Management of cocoa

germplasm by morphological characterization using botanical descriptors and agronomic and

technological characterization and evaluation have ever been prerequisites for successful crop breeding.

However, the possibilities of modern biotechnology confer increased significance and strategic

importance to systematic characterization of the crop. One quarter of the 44 participating experts

described research activities in this field.

A central role in this field is played by the characterization of the phenotypes of the roughly 2500

accessions of the International Cocoa Genebank of the Cocoa Research Unit at the University of the West

Indies, Trinidad, that manages germplasm from South and Central America, and other countries. This

project, started in 1990, is expected to facilitate the utilization of the available genetic resources by the

international cocoa community through the international cocoa germplasm database located at the

University of Reading, United Kingdom. In addition to the activities in Trinidad, other similar projects

were noted by experts from CATIE in Costa Rica, CEPLAC/CEPEC in Itabuna, Brazil, and the USDA

National Germplasm Repository in Miami. This research assists the development of an efficient cocoa

COCOA BIOTECHNOLOGY 339

germplasm core collection, and also aims at standardizing the characterization methodology. It provides

essential botanical and agronomic information for plant breeders. Mislabeled accessions and duplicates

can be identified as the data is analyzed. This should improve cocoa breeding efficiency world-wide and

allow a better selection of hybrid parents. Valuable results can be expected within the next four to nine

years.

Genetic characterization. About 27 % of the 44 responding experts described research projects on

genetic characterization of cocoa; five of the experts were also involved in the morphological and

agronomic characterization and the conservation and management of complete plants or plant parts. One

project was related to the genetic characterization of the cocoa witches' broom pathogen.

Biochemical markers (isozyms or proteins) or molecular marker technology--for example, restriction

fragment length polymorphism (RFLP) and random amplified polymorphic DNA (RAPD)--is being used

to produce genetic linkage maps and for quantitative trait loci analyses. With the help of these methods,

genomic regions are tagged that are associated with yield components (pod weight, pod index, seed

weight, self-incompatibility), formation of yield and crop physiology (dry matter partitioning, light

interception, canopy architecture), heritability of the resistance to diseases (Phytophthora and

Moniliophthora pod rot, and witches' broom), fat content and quality (fatty acid profile), and flavor

characteristics (alkaloids, protein storage). Information on the number of genetic factors expressing a

character, their localization on the chromosomes, and the relative contribution of a given factor in the

factor expression can be evaluated. These tools should speed cocoa breeding. For the end user

(processors) these methods represent a strategic source of information on raw material characteristics

and--in combination with the possibility of long-term m vitro preservation of genetic resources and rapid

micropropagation--a competitive advantage for product innovation. Again, the experts expect project

goals to be achieved within two to ten years.

In vitro techniques. Several in vitro techniques are being developed for use in cocoa. These include

regeneration and micropropagation (axillary bud culture; regeneration of somatic embryos of non-zygotic

origin; protoplast culture; micropropagation in liquid culture) and germplasm preservation and

conservation by means of cryopreservation or in liquid cultures. Eleven experts (25%) described research

activities in these fields. All of them were involved in the development and improvement of in vitro plant

regeneration. This suggests that reliable and efficient protocols for regeneration and propagation of cocoa

plants from cells are not entirely developed. Several groups are developing systems to establish

340 N. GOTSCH

appropriate protocols for plant propagation from somatic embryos, and for regeneration from protoplasts.

Improved methodology should speed crop breeding, assist selection and multiplication, and provide new

opportunities for genetic engineering.

Research institutions of two participants were engaged in the long-term in vitro preservation and

conservation of genetic resources which should allow easier conservation and exchange of genetic

resources.

Genetic engineering. Only two participants described research projects involving genetic engineering.

This may be because the in vitro regeneration of cocoa--a prerequisite to genetic engineering--only

recently became possible. One of the described projects attempts to genetically transform cocoa by

introducing foreign genes conferring resistance to fungal pathogens and insect pests. The aim is to obtain

transgenic somatic embryos containing the test genes by means of Agrobacteriura tumefaciens and

biolistics, then to regenerate transgenic plants from these embryos. However, up to the present, the

frequency of genetic transformation of cocoa cells is very low. Nevertheless, first transgenic plants are

expected to be regenerated soon (1996), and first field trials of transgenic disease or insect resistant

cocoa are expected by the year 2000 The second of the two projects did not list specific goals but it

mentioned the use of genetic engineering after successful development of more efficient in vitro methods.

Applied Research and Development

The most important tool for applied research and development is crop breeding, including mutation

breeding. Fourteen of the 44 participating experts described activities in this field; seven of them were

breeding for enhanced resistance or tolerance to pathogens as the most important goal.

Nine experts mentioned activities relating to disease and pest control (outside of resistance breeding);

four of them were active in developing methods for the biological and microbial control of cocoa

pathogens, whereas seven were developing improved methods of integrated pest and disease

management.

From the experts' answers, the overall importance of various goals could be evaluated. The most

important goals were reducing requirements for non-renewable inputs (pesticides, fertilizer), reducing

yield losses caused by diseases, and improved knowledge of the cocoa crop, and yield enhancement.

For cocoa breeding particularly, primary goals are reducing yield losses caused by diseases, and

reducing requirements of non-renewable inputs and increasing yield. The same three goals had highest

priority for experts describing projects in disease and pest control (biological and microbial control;

COCOA BIOTECHNOLOGY 341

integrated management of diseases and pests), and for experts improving production systems by means of

agronomy. However, it should be noted that this evaluation of the importance of various goals does

neither weight these goals in terms of funding and scientific staff available, nor does it provide precise

information on the chances for a successful achievement of goals and the effects of such achievement on

cocoa production.

Although, improvement of cocoa quality parameters was mentioned less frequently as a research goal

compared to the reduction of yield losses caused by diseases, it was noted by important research

institutions such as the Malaysian Cocoa Board, MARDI in Malaysia, CATIE in Costa Rica, and by those

responsible for cocoa research at CIRAD, and by several participants from research departments of the

cocoa processing industry.

The rehabilitation and replanting of old cocoa areas was an important integrated research goal noted

by several experts. Various intermediary and applied tools would have to interact to achieve this goal and

to stop unsustainable cocoa production that requires expanding into previously unused forest.

Even though post-harvest processing was not explicitly included in this survey, several projects

reported dealt with post-harvest quality monitoring and improvement during cocoa fermentation and

drying, and also during chocolate manufacturing where modem biotechnology (with the help of enzyme

technology) can play a significant role. Improved and new innovative chocolate products could increase

consumer demand and thus raise world cocoa market price.

One project reported on cocoa by-product development for possible positive benefit for the

environment and as a source of additional income for small peasant farmers in Africa.

Factors Constraining Cocoa Research

The emphasis on intermediary research and development in cocoa research reflects the continuing lack of

basic knowledge on genetic diversity and on the qualities and characteristics of cocoa germplasm, and

also with respect to the value of clones for practical breeding. The systematic use of intermediary

research and development to cocoa is still emerging; its reliability and efficiency remains to be validated.

Moreover, basic knowledge on the ecobiology of pests and diseases is still scarce.

These problems have been blamed on a lack of continuity and research co-ordination. Absence of

long-term commitment increases turnover of scientists and prevents creation of a core of qualified

personnel. Continuity of personnel is a necessary prerequisite not only for basic sciences but also for

342 N. GOTSCH

fieldwork (collection and evaluation of genetic resources) and for research at the smallholders' level--all

time consuming and complicated long-term tasks.

From the point of view of international research, the establishment of an international center for

cocoa research is regarded as essential by various experts. Such and institution could internationally co-

ordinate and structure long-term research, should efficiently procure the necessary funding for research,

and provide better trained scientists and better equipped research facilities.

A general lack of inter-institutional collaboration and exchange of experience and information is felt.

Also, the international exchange of germplasm is impeded by quarantine regulations and an absence of

legal framework for exchange of breeding material. Persistently low cocoa prices affect projects--

particularly the commodity funded ones--by local institutions and corporations. Also, low pricing

restricts implementation of research results in cocoa production because of high costs in relation to the

commodity price level. One example of such a project is integrated control of the cocoa pod borer.

Research in producer countries is impeded by budgetary restrictions of national governments and

relatively expensive hard currency imports. This is especially manifest in shortages of laboratory

equipment, chemicals, and equipment for fieldwork. Shortage of funding for additional staff, and low

salaries frequently slow research. 'Field personnel' such as practical breeders continue to doubt the

potential contribution of modern biotechnology to improving conventional breeding methods. An over-

reliance on genetic resources and an under-emphasis on genetic principles is perceived by some of them.

Scientists from more traditional applied fields fear that research on modern biotechnology is conducted at

the expense of applied research. This hinders the proper evaluation of modern biotechnology and its

integration into the more directly practical methodologies In principle, at least, the use of modern

biotechnology should be a cost-effective way of overcoming constraints and should complement rather

than compete with traditional breeding. Commercial breeders and agronomists feel that they are best

placed to identify and prioritize the biotechnologies as tools in strategic research, but according to them

the decisions on research investments are often taken by fund donors.

FUTURE DEVELOPMENTS

This section presents the results of the forecasts made by the experts in the third round of the survey

regarding the genetic characterization, improvement and use of cocoa germplasm, the chances of

improving cocoa bean yield and modifying cocoa quality, producing cocoa components in vitro or cocoa

substitutes with the help of crops other than cocoa. The forecasts relating to aspects of cocoa crop

COCOA BIOTECIqNOLOGY 343

protection (resistance breeding, genetic engineering to achieve improved tolerance to pests and diseases,

biological and microbial pest and disease control) are presented elsewhere [4].

The results are depicted graphically using the 'box-whisker' plots (Figures 2-6). A hatched box plot

divides the data into four quartiles and encloses the middle 50 percent, the interquartile range. The

median M is represented as a horizontal bold line inside the box. Vertical lines, known as 'whiskers,'

extend from each end of the box. The whiskers are drawn from the end of the box to data points within

1.5 interquartile ranges from the respective quartile. Data values that fall beyond the whiskers but within

three interquartile ranges are plotted as individual points. For well outside points, the system uses a + for

easy distinction. The soitware can also display 95 percent confidence interval around the median (see 5);

this option is not used here, however, statistically significant differences relevant for the interpretation of

the experts' forecasts are discussed. The abbreviations below each box are explained in the caption (e.g.,

in Figure 2 Y stands for yield). The numbers following the letters stand for the three scenarios described

above (1 = 'business-as-usual' scenario; 2 = 'improvement' scenario; and 3 = 'breakdown' scenario),

Thus, Y1 in Figure 2 depicts the diagrammatic statistical analysis for the chances of morphological

characterization and documentation of yield characteristics in the 'business-as-usual' scenario.

General Aspects

With a few exceptions, the three statistical values, Q1, Q3 and M, are highest in the 'improvement'

scenario which represents the most favorable research environment. In most cases, the quartile-limiting

factors Q1 and Q3 are higher in the 'improvement' scenario compared with the 'business-as-usual'

scenario. Another observation that can be made consistently is that the chances of success are much

reduced in the 'breakdown' scenario compared with the other two scenarios. The medians in this scenario

are statistically significantly lower at a five percent level for most of the characteristics compared with the

medians of the other two scenarios for the same item. These findings and the small interquartile range in

the 'breakdown' scenario for most of the characteristics reflect the experts' consensus that this scenario

represents a very low base line, which would cause more or less the complete collapse of any future

research progress in cocoa. For these reasons the following discussion of specific technologies places

most emphasis on the 'business-as-usual' scenario.

344 N. GOTSCH

Genetic Characterization of Cocoa

Molecular markers can be used for fingerprinting and mapping. These markers allow for selection of traits

in mature plants (yield and bean quality) at the seedling stage. Molecular markers are preferred over

botanical and biochemical markers because their expression is not influenced by the environment.

However, as Figure 2 shows, in the 'business-as-usual' scenario there is relatively little chance for genetic

characterization of yield and quality characteristics. Low scores reflect the experts' belief that there are

inherent difficulties in reliably measuring the trait on the basis of individual plants and that, although

progress is likely, practical breeding applications would be uncertain due to expense of this methodology

and difficulties in identifying appropriate quantitative trait loci. There is a general consensus that, within

the given time frame, good opportunities exist only where the character is of a simple nature. Because so

little of the (conventional) genetics of even the simplest traits is known, adequate linkage maps are likely

to be difficult to construct. Complex characteristics such as flavor are little understood. The controversial

nature of a quantitative assessment of the chances of genetically characterizing specific traits is reflected

in the wide interquartile ranges for many characteristics.

100

80

Z

60

40

20

0

. . . . . . . . . . . T . . . . T -

/

YI Y2 Y3 Cbl Cb2 Cb3 FI F2 F3 Yield and quality characteristics to be characterised genetically/scenarios

Figure 2. Chances of genetic characterization of cocoa yield and quality characteristics (Y: yield (pod weight index, self-incompatibility); Cb: cocoa butter content and fatty acid profile; F: flavor characteristics).

COCOA BIOTECHNOLOGY 345

In V/tro Techniques

In vitro methods are expected to make cocoa improvement faster and more efficient. First, these methods

are the basis for more effective propagation of improved clones, and for the conservation and more

efficient exchange of valuable breeding materials. Second, micropropagation and in vitro regeneration are

the foundation for genetic engineering. Figure 3 depicts the likelihood of success in various in vitro

regeneration/multiplication techniques. The first three boxes show the overall chances for

micropropagation/in vitro regeneration without specifying particular techniques. In the 'business-as-

usual' scenario half the experts assess the chances for micropropagation/in vitro regeneration at least

50 percent that these methods would be developed to such an extent that they could be efficiently

integrated into applied research and development (traditional breeding). The most promising method for

in vitro regeneration is somatic embryoganesis, which therefore has been investigated separately. As seen

in Figure 3, the interquartile range for this specific technique is smaller in all three scenarios compared

with the ranges of the comparable scenario in the more general case presented earlier. However, the

median values do not differ significantly at the 95 percent level. The considerable chances

lOO

8O

60

.~ 40

20

!

M1 M2 M3 Rsl Rs2 Rs3 A1 A2 A3 G1 G2 G3 In vitro techniques/scenarios

Figure 3. Chances of in vitro techniques (M: micropropagation/m vitro multiplication; Ks: regeneration of somatic embryos, A: androgenetic doubled haploids; G: germplasm conservation (cryopreservation)).

346 N. GOTSCH

attributed to in vitro regeneration/multiplication techniques are consistent with the fact that not only has

somatic embryogenesis been achieved with cocoa, and rooted plantlets have been generated from somatic

embryos.

Techniques for cryopreservation of germplasm are expected to facilitate conservation of genetic

resources by lowering the cost of maintenance of gene banks, hence facilitating the exchange of breeding

materials.

In V/tro Production of Cocoa Components

Two different methods for the in vitro production of economically important cocoa components were

assessed by the experts: in vitro production with the help of cocoa cells or parts of them; and in vitro

production with the help of cell cultures other than cocoa (including micro-organisms).

These issues were hotly disputed in discussions of developmental policy. Non-governmental devel-

opment organizations in particular were concerned about the technologically inherent potential for

substitution of cocoa constituents. Nevertheless, as Figure 4 shows, in vitro production of cocoa

components with the help of cocoa cells or parts of them was not believed to be very promising by the

experts. The chances for the production of flavor components were considered less favorable than those

of cocoa butter components presumably because flavor formation is a complex process about which little

is known.

One expert noted that the production of cocoa butter by m vitro cultured cocoa somatic embryos was

attempted years ago but produced fatty acids that were too unsaturated (like immature zygotic embryos),

suggesting that technical problems may exist also in producing acceptable cocoa butter substitutes in

vitro. In addition, the costs may be prohibitive.

Figure 4 also shows the chances of in vitro production of cocoa components with the help of cell

cultures other than cocoa or with the help of micro-organisms. The prospects of this approach were rated

slightly more favorably than those o f in vitro production with the help of cocoa cells or parts. However,

the median values of the respective boxes did not differ significantly at the 95 percent level. The experts

agreed that through co-operation of biochemists and molecular biologists, genes involved in

characteristics such as flavor and fatty acid profiles may be identified, isolated, and introduced into

bacteria and yeasts, enabling production of relevant components in bioreactors. One expert reported

COCOA BIOTECHNOLOGY 347

100

8O

60

4O

20

0

- O

i Bcl Bc2 Bc3 Bol Bo2 Bo3 Fcl Fc2 Fc3 Fol Fo2 Fo3

Components to be produced in vitro/scenarios

Figure 4. Chances of in vitro production of cocoa components (Bc: cocoa fatty acids from cocoa cells or part of them; Bo: cocoa fatty acids from cell cultures other than cocoa or from micro-organisms, Fc: flavor components from cocoa cells or part of them; Fo: flavor components from cell cultures other than cocoa or from micro-organisms).

that a team from the U.K. cloned the gene for the cocoa seed storage protein believed to be important for

chocolate flavor development, and that the gene could be expressed in yeast, presumably to make a lot of

protein for experimental purposes.

One expert stated that the chocolate industry prefers beans with good chocolate flavor, low

astringency, low bitterness, low acidity, low off-flavors, and with increased butter content to in vitro

produced chocolate components. This view was supported by an expert from the chocolate industry who

judged that this research would not result in economically competitive products, being merely a waste of

effort for purely academic reasons.

The experts agreed that cocoa butter-like storage lipids may be produced by transgenic whole plants.

Genetically engineering temperate oilseeds such as sunflower, canola, or soybean to produce lipids close

to cocoa butter may be technically and economically more promising than in vitro production of those

components. One possibility is the transfer of cocoa genes into those other plants. However, as one

expert noted, in his comments, this may not even be necessary: First, temperate oilseeds could perhaps be

genetically engineered to make cocoa butter-like storage lipids without introducing genes from cocoa.

348 N. GOTSCH

Second, a Spanish laboratory has a collection of sunflower mutants with altered fatty acid profiles, and

their owner claims to be able to breed sunflower to make storage lipids with a wide range of fatty acid

compositions.

No consensus exists among the experts concerning the acceptance of products based on these

methods possibly because many cocoa technology experts are not necessarily experts in assessing

consumer decision making.

Transgenic Cocoa

According to Figure 5, the experts expect good results from contributions of genetic engineering to

improvement of quality characteristics. One half of the respondents predicted at least a 50 percent chance

in the 'business-as-usual' scenario that cocoa butter content could be modified by developing transgenic

cocoa (median value and upper quartile-limiting factor coinciding at 50 percent). However, there was no

consensus about the technological feasibility of obtaining cocoa with butter content above the current

average of 55 percent. In comments during the final round of survey, one expert noted that cultivars with

fat content up to 62 percent are already known and that the prospect of more than 65 percent exists.

Another expert expected innovative companies to use biotechnology to genetically engineer or breed

cocoa with some novel features (reduced astringency), patent it, and contract with farmers to grow it.

100

8O

Z

60

.~ 40

20

Ccl Cc2 Cc3 Cql Cq2

4

Cq3 F 1 F2 F3 Components to be genetically engineered/scenarios

Figure 5. Chances to genetically engineer quality characteristics of cocoa (Cc: cocoa butter content; Cq: cocoa fatty acid profile; F: flavor characteristics).

COCOA BIOTECHNOLOGY 349

Those experts who were critical of an over-optimistic assessment of the future contributions of

genetic engineering mentioned the short time flame available for obtaining results in perennial crops.

According to these experts useful genes have not been identified. Furthermore, the usefulness of

transformed characteristics will always need to be established in the field before any application in

practical breeding is accepted. Another expert noted that the transformation rate of cocoa cells is still

low, and regeneration &whole transgenic plants has not been achieved.

Cocoa Breeding

The experts assessed the chances of breeding cocoa with improved yield and quality characteristics.

'Improved yield' meant an increase in average bean yield of at least 30 percent compared with the present

average yield in a region, given good production management and sufficient input supplies such as

fertilizer and labor. According to Figure 6, the prospects for breeding new cocoa cultivars with enhanced

yield and increased cocoa butter content were considered promising. The median values anticipated for

the 'business-as-usual' scenario were 60 and 50 percent whereas the chances for the other two quality

attributes--modification of the fatty acid profile, and flavor characteristics--were considered relatively

low.

100

80

60

14° 20

0

Figure 6. Chances (Y: enhanced yield characteristics).

Y1 Y2 Y3 Col Cc2 Cc3 Cql Cq2 Cq3 F1 F2 F3 Yield and quality characteristics to be improved by breeding/scenarios

of breeding new cultivars with improved yield and quality characteristics potential; Ce: cocoa butter content; Cq: cocoa fatty acid profile; F: flavor

350 N. GOTSCH

There was general consensus that progress in breeding through hybridization will remain a major

method in applied cocoa research and development for the next decade. The experts agreed that

improved genetic knowledge of breeding materials will ensure the development of improved varieties.

However, not only will progress in intermediary research and development foster breeding progress but

also improved methods of applied breeding will ensure advances in this field

Those experts advocating a more pessimistic view on the prospects of future breeding progress

perceived a lack of interest in breeding. Furthermore, they argued that well-designed breeding programs

with long-term strategies are almost non-existent, did not exist in the past, and that breeding methods

have been wrong in most cases. Other experts complained that internal research funding in producer

countries was shrinking dally and outside funding was needed for progress. They suggested that agencies

in the leading consumer countries should support research in the producer countries to a greater extent

than currently.

CONCLUSIONS

Existing publications on cocoa research and development primarily present the research status and the

production constraints; only limited information is given regarding potential future developments. The

results of this article should prove useful to policy makers in setting priorities for cocoa research and

development. Furthermore, this study may guide cocoa producers and researchers in selecting future

production strategies.

The experts' quantitative assessments demonstrate that a worsened research environment--

represented by the 'breakdown' scenario---would lead to collapse of research progress; whereas a more

advantageous institutional and funding environment would considerably improve future research progress

in both applied and intermediary areas.

Strong competition for financial resources is clearly evident. In the course of the various survey

rounds, a lively controversy developed regarding the importance and interdependence of various research

tools, in particular, concerning the role of modern biotechnology (in vitro methods, molecular biology,

and genetic engineering) and its integration into traditional applied R&D, especially practical breeding.

New methods of molecular biology and biotechnology compete for scarce resources with the more

traditional methods. A serious threat to traditional fields, in particular cocoa breeding, is perceived by

experts active in these fields. According to Sasson [10], strengthening conventional applied research and

development is a necessary prerequisite for successful implementation of intermediary R&D. This author

COCOA BIOTECHNOLOGY 351

expects the development of micropropagation methods to enhance traditional plant breeding because only

breeders can effectively test the emerging varieties. Clearly, the producer countries must strengthen their

capacity for applied research and development. This, of course, requires additional funding. In fact,

traditional breeders fear that they would not be able to meet these additional requirements in a situation

where even now the level and continuity of funding and personnel resources available are rarely

commensurate with the task.

In view of the survey results, promising developments can be achieved through: (1) Phenotypic

characterization of thousands of uncharacterized and thus functionally useless accessions in gene banks.

Such characterization could lead to identification of associated characteristics and facilitate detection of

mislabeled accessions and duplicates, and hence make traditional breeding more efficient. (2) Increased

use of the recently established somatic embryogenesis and the ability to induce somatic embryos to

develop into rooted plantlets [9]. These methods may allow more efficient propagation and multiplication

of superior clones, and more efficient conservation and exchange of valuable breeding material.

It is further evident that improved production through biotechnology will not occur without an

adequate allocation of resources to traditional applied research and development such as conventional

breeding. The application of intermediary R&D should be the most cost-effeetive way of overcoming

constraints to production. Such application should complement rather than compete with applied research

and development. The optimal allocation of financial resources to the different fields of cocoa research is

the domain of research priority setting which is beyond the scope of this paper.

As cocoa cultivars with improved yield are adopted by a considerable number of farmers, the increase

in output would reduce the world market prices. Unless demand increases correspondingly, other

producers would be forced to adopt the improved technology or withdraw from production in the long

term [7]. Therefore, the expected socio-economic impact of promising future technological developments

has to be carefully analyzed to ensure the interests of all producer countries.

ACKNOWLEDGMENTS

Numerous cocoa experts from various fields of cocoa research contributed to this study. The author

would like to thank them for carefully completing the questionnaires and providing helpful comments.

The author is specially indebted to Julie Flood, Albertus Eskes, Doug Furtek, and Rob Lockwood. Any

errors are the responsibility of the author. This study was funded by the Swiss National Science

Foundation.

352 N. GOTSCH

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