Genetic Engineering of Plants Agricultural Research Opportunities and Policy Concerns (1984) / Chapter Skim
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Somatic Cell Genetics
Somatic Cell Genetics
Pages 33-39
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From page 33... ...
The ability to regenerate plants from cells in culture has given rise to new techniques generally referred to as somatic cell genetics that both increase the supply of genetic diversity and make possible more efficient selection. Selection Millions of cells, each a potential plant, are typically grown in a single flask in cell-suspension culture (see Cell Culture, p.
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From page 34... ...
Through experiments with agricultural species began just a few years ago, many can now be routinely regenerated from callus culture. In this approach, a tiny piece of tissue is snipped from a seeclling shoot or other appropriate plant part and placed in a petri dish containing the plant hormones auxin and cytokinin, along with organic and inorganic nutrients.
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From page 35... ...
These cells then regenerate either by forming roots and shoots or else by forming somatic embryos, which then differentiate into entire plants. Achieving regeneration from single cells is far more difficult than starting from a clump of tissue.
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From page 36... ...
This offers the opportunity to fuse Protoplasts from different plants to form hybrids that combine their characteristics. Photograph A shows plantlets of a wild species of clover regenerating from a tissue culture derived from an isolated protoplast.
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From page 37... ...
What is clear is that the phenomenon is ubiquitous, occurring in rice, corn, wheat, barley, potato, alfalfa, rape, and other species, and affecting many agronomically useful traits. In several species, for instance, the somaclonal variants include resistance to diseases: sugarcane has developed resistance to eyespot disease, Fiji virus, downey mildew, and smut; potatoes to late anct early blight; corn to Southern corn leaf blight; and oil seed rape to vitricular disease.
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From page 38... ...
Variation in plant height is compared to parent plants on the extreme right and left. Seed head morphology can differ markedly from the parent type shown in the center of the top photograph.
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From page 39... ...
Somaclonal variation may also provide genotypes suited for tropical environments genotypes able to tolerate heat or acidic soils containing harmful levels of aluminum and manganese.
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