Agriculture Reference
In-Depth Information
the same region as the crops are cultivated. One of
the environmental concerns that have been expressed
is that the genetically engineered traits will be trans-
ferred to these weedy species, which will mean that they
will spread and be difficult to control. Indeed, inves-
tigation of this has shown that these transgenic traits
will indeed be transferred to weedy species, even if not
quickly, in the longer term it is probably inevitable. The
question that arises is really how much of an advan-
tage will the plants in wild populations gain from the
presence of such a gene, and hence spread. Clearly
when invading a farming environment in which the
particular herbicide is used any genotype with resis-
tance to that herbicide will have a distinct advantage
and spread. However, when a herbicide with a different
mode of action is used the advantage should be elimi-
nated, unless the resistance is 'horizontal' and covers a
number of different herbicides. In the situation where
no herbicide is used, the persistence of the transferred
gene will depend on whether it affects any other traits
(positively or negatively in terms of natural selection)
and particularly whether it carries a 'penalty' to its car-
rier. For instance, it may mean that the plant makes
unnecessary use of metabolic energy producing some-
thing that is not needed. Similar scenarios will exist
for other genes that are transferred into crop plants.
The 'cost/benefit analysis', in the broadest sense of each
is needed and any possible uncertainty investigated in
detail. All technology carries benefits and costs - it is
a question of the balance between the two, but must
be heavily weighted in favour of safety to the consumer
and the environment!
Development of the techniques, or their application,
to produce transgenic crops has been costly and biotech-
nology based seed companies are anxious to recover their
costs. It remains to be shown whether the advantages
of transgenic lines will be sufficient to outweigh the
cost incurred and whether investments are recouped.
However, the 'weight' of investment must not cloud
the scientific basis of any risk assessment.
Many of the early transgenic plants have resulted
from genetic engineering of cultivars on which there
is no plant variety protection (i.e. they have no legal
owner). If transgenic crops are to have a large impact
on agriculture then genetic engineering companies need
to develop cultivars which are transformed for spe-
cific traits that cannot readily be produced by more
traditional means and to work in collaboration with
traditional breeding programmes/companies in order
to keep development of the myriad of other characters
increasing in performance, and in order to compete
successfully in commercial contexts. But, at least in
the immediate future, perhaps the greatest profits from
genetically engineered crop species will be achieved by
the legal profession who are likely to be called upon to
sort out some of the difficulties that this new technol-
ogy generates, particularly in the area of 'Intellectual
Property' (IP)!
Plant transformation methods complement more tra-
ditional plant breeding work by increasing the diversity
of genes and germplasm available for incorporation into
crops and by (perhaps) shortening the time required
for the development of new cultivars. Genetic engi-
neering of plants also offers exciting opportunities for
the agrochemical, food processing, speciality chemi-
cal and pharmaceutical industries in developing new
products within crop species and offering new man-
ufacturing processes. However, it is highly unlikely
that these techniques will replace the traditional tech-
niques that have been used in the past. Recombi-
nant DNA techniques will, rather, add to the 'array
of possibilities' to plant breeders in future cultivar
development.
THINK QUESTIONS
(1) You are employed as barley breeder for a com-
mercial company. At present the company does
not have any greenhouse facility. You are try-
ing to convince your peers that the breeding
programme would benefit from having a green-
house: List five uses you would have of a green-
house in your breeding programme if one were
available.
Great job (we hope!) you have convinced the
board of directors to proceed with purchasing a
new greenhouse. List five features you would like
to request to have in the new greenhouse facility.
(2) A friend has just bred a new apple cultivar, which
has good yield, fruit shape, storage quality colour
and appearance. However the taste quality is some-
what lower than might be desired. Nonetheless,
your friend has decided to release the cultivar and
has asked you to suggest a possible name. What is
