Miracle or menace? : biotechnology and the third world / by Robert Walgate.

  • Walgate, Robert
Date:
[1990]
Catalogue details

Licence: Attribution-NonCommercial-NoDerivatives 4.0 International (CC BY-NC-ND 4.0)

Credit: Miracle or menace? : biotechnology and the third world / by Robert Walgate. Source: Wellcome Collection.

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    CHAPTER 3 PLANT TISSUE CULTURE Before biotechnology can have any impact on a plant, the plant must be amenable to being grown in tissue culture, which rapidly multiplies all the genes of a single plant at once (see box page 2). Tissue culture is a two-edged sword. It can bring developing countries great benefits, particularly in plant breeding and multiplication of elite plants; but it also threatens to substitute certain high-value crops by Northern-based industrial processes. Many tropical plants cannot be grown in the temperate climates of the North. But their cells — producing the valuable products — could be grown in a laboratory anywhere in the world.Under threat, for example, are the production of insecticides (Pyrethrins) from the white daisy-like pyrethrum flowers grown in Kenya, Tanzania and Ecuador, and the production of anti-cancer drugs from the Madagascar rosy periwinkle. If plant tissue culture is developed to its logical extreme, many of the Third World's cash crops, such as coffee or cacoa, could be produced in factories in London or Boston. At its simplest, tissue culture is just an efficient — and disease-free — way of taking a multitude of cuttings from a single useful plant. This could be one that happens to produce a high agricultural yield, or that has proved resistant to disease. But it is also the essential basis of plant genetic engineering, which begins by inserting genes into single cells in tissue culture. But it has many variants and many applications. Tissue and cell culture In tissue culture, a small piece of organised tissue — essentially a mini-cutting — is grown on solid growth medium. This is a sterile soil substitute, or a nutrient jelly, which also contains plant hormones needed for plant cells to grow and divide. The cells multiply, and the pieces of tissue can be repeatedly divided until enough has been produced [1]. Tissue or cells for culture can be taken from almost any part of the
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