TABLE OF CONTENTS Most of our global agricultural production relies on a very limited number of widely cultivated staple crops, such as wheat, rice, maize and soybean. The introduction of transgenic varieties of these major crops is likely to increase their dominance further.
This may be particularly true if output traits are modified so that the crops accumulate new products and so require even larger acreage. In some cases, the transgenic crop may produce a compound currently obtained from a minor crop, resulting in displacement of the latter. These trends may be undesirable for ecological reasons as they increase the tendency towards extensive monocultures that may be more susceptible to pests or diseases. However, a more compelling argument against a proliferation of transgenic mainstream crops with novel output traits is the problem of segregation (see Section 13.5.2). A feasible alternative strategy is to develop new crops as sources of the novel products. As well as being more easily segregated, the new crop species will already synthesise the products of interest without the need for convoluted manipulations of biochemical pathways and the possible side effects that may ensue. Oil crops provide a useful example of the way such new crops might be developed.
