Genetic Engineering of Plants Agricultural Research Opportunities and Policy Concerns (1984) / Chapter Skim
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Crop Improvement
Crop Improvement
Pages 5-14
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From page 5... ...
Plant remains found in ancient Egypt and Mesopotamia indicate that plant cultivation was already widespread by that time. In earlier ruins of pre-Incan Indian villages in Peru, archeologists have uncovered Lima beans that have seeds nearly 100 times larger than those of wild Limas in the area.
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From page 6... ...
They also learned that sometimes chromosomes are present in multiple copies, or in reduced number, anct that this particular closage affects gene expression. The First Biological Revolution The foundation of Mendelian genetics enabled plant breeders to cross plants with new precision, carefully manipulating the plant genome to produce new, improved varieties.
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From page 7... ...
In the United States, half of this gain is generally attributed to the simultaneous improvements in farm management in cropping practices, in farm machinery, and especially in the development of new agricultural chemicals such as pesticides, fertilizers, and herbicides. Similarly, the introduction of improved wheat and rice varieties in South Asia was accompanied by a heavy investment in irrigation and agricultural chemicals.
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From page 8... ...
Because of such natural breeding barriers, the plant breeder in search of useful new variants is confined to members of the same species or closely related species. Compounding the problem, many major crops have been under cultivation for thousands of years, which has led to an increasingly homogeneous gene pool.
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From page 9... ...
that are experiencing food shortages." According to W David Hopper, vice president of the South Asia Region of the World Bank, although there has not been as massive a famine as the one in India in 1943, hunger and maInourishment are still pervasive worldwide.
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From page 10... ...
Yet all three the agricultural technologies, economic incentives, and infrastructure- coalesced in the 1 960s in India and China, Hopper said. Norman BorIaug's improved wheat varieties were introduced, as were the advanced rice varieties of the International Rice Research Institute.
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From page 12... ...
Molecular Genetics Genetic engineering enables molecular biologists to reshuffle genes in combinations not possible in nature, opening up a vast new source of genetic diversity for crop improvement. "One of the most remarkable achievements of genetic engineering and molecular biolov~,v is that we now operationally have a kind of world gene pool," Bogorad explained.
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From page 13... ...
Molecular biologists will need to work closely with plant breeders to identify promising projects for genetic engineering. When a new variety is developed in the laboratory, it will face the same scrutiny as does any new variety; it will need to undergo lengthy evaluation in the field.
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From page 14... ...
It will entail bringing underutilized plants into production and a continued search for new, valuable germ plasm.
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