Shattering
Shattering

Author: Cary Fowler

Publisher: University of Arizona Press

Published: 1990

Total Pages: 300

ISBN-13: 9780816511815

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It was through control of the shattering of wild seeds that humans first domesticated plants. Now control over those very plants threatens to shatter the world's food supply, as loss of genetic diversity sets the stage for widespread hunger. Large-scale agriculture has come to favor uniformity in food crops. More than 7,000 U.S. apple varieties once grew in American orchards; 6,000 of them are no longer available. Every broccoli variety offered through seed catalogs in 1900 has now disappeared. As the international genetics supply industry absorbs seed companies—with nearly one thousand takeovers since 1970—this trend toward uniformity seems likely to continue; and as third world agriculture is brought in line with international business interests, the gene pools of humanity's most basic foods are threatened. The consequences are more than culinary. Without the genetic diversity from which farmers traditionally breed for resistance to diseases, crops are more susceptible to the spread of pestilence. Tragedies like the Irish Potato Famine may be thought of today as ancient history; yet the U.S. corn blight of 1970 shows that technologically based agribusiness is a breeding ground for disaster. Shattering reviews the development of genetic diversity over 10,000 years of human agriculture, then exposes its loss in our lifetime at the hands of political and economic forces. The possibility of crisis is real; this book shows that it may not be too late to avert it.

Tissue Culture of Trees
Tissue Culture of Trees

Author: John H. Dodds

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 157

ISBN-13: 1468466917

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1 John H. Dodds The culture offragmen ts of plant tissue is not a particularly new science, in fact as long ago as 1893 Rechinger (1893) described the formation of callus on isolated fragments of stems and roots. The culture of plant tissues in vitro on a nutrient medium was performed by Haberlandt (1902), however, his attempts were unsuccessful because he chose too simple a medium that lacked critical growth factors. Over the last fifty years there has been a surge of development in plant tissue culture techniques and a host of techniques are now avail able (Dodds and Roberts, 1982). The major areas are as follows. Callus Culture Callus is a rather ill-dermed material. but is usually described as an un organised proliferating mass of tissue. Although callus cultures have a great deal of potential in the biotechnological aspects of tissue culture, i.e. secondary product formation, they are not very suitable for plant propagation. The key reason for their unsuitability is that genetic aber rations occur during mitotic divisions in callus growth (D'amato.l965). The aberrations can be of a major type, such as aneuploidy or endo reduplication. It follows therefore that the genetic status of the re generated plants is different from that of the parent type. In general terms this genetic instability is undesirable, but there are occasions when a callus stage can be purposely included to diversify the genetic base of the crop.