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The Great gene robbery
1990
Bellamy, David
Presents the problem that as crops are specialized, older species are lost and no amount of genetic engineering can protect food crops with genetic diversity preserved in germplasm banks. Uses the potato species found in the Andes and the contrast between old and new cultivation styles to illustrate this problem.
Afficher plus [+] Moins [-]Shattering
1990
Fowler, Cary | Mooney, P. R. (Patrick R.)
"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."--Amazon.com.
Afficher plus [+] Moins [-]Selection of Potato Haploid Parents for Use in Crosses with 2x (2 Endosperm Balance Number) Wild Species Texte intégral
1990
Yerk, G. L. | Peloquin, S. J.
Haploids (2n = 2x = 24) of Solanum tuberosum L. may be used to tap the genetic diversity present in the related wild species by producing haploid ✕ species hybrids (2n = 2x = 24). The purpose of this study was to identify elite haploids for use in crosses to wild species based on percentage tuberization of their progeny, number of fruit per pollination and seeds per fruit, and their genotype for parallel spindles (ps), a meiotic mutant causing 2n pollen formation. A group of 73 haploids were selected for good flowering and cultivartype haulms. To determine their respective ps-locus genotypes, the haploids were testcrossed as females to four plants of S. chacoense BITT. (psps). All 21 of the haploids that were successfully crossed to S. chacoense BITT. produced families with a high percent tuberization. Only one of the 39 families tested had percentage tuberization that was significantly lower than the average family performance. Eighteen of the 21 haploids were Psps, one was psps, and two gave families that deviated significantly (P < 0.05) from a 1:1 ratio. Six haploids had average seed set of greater than 40 seeds per fruit in all combinations for which twenty or more pollinations were made. Selection of elite haploids should increase the potential of the 4x ✕ 2x breeding scheme by: (i) increasing the amount species germplasm that may be selected among, (ii) making production of haploid ✕ wild species hybrids morefficient, and (iii) increasing the amount of the germplasm pool that can be transferred to the tetraploid level using 2n pollen. Present address of G.L. Yerk, Dep. of Agronomy and Plant Genetics, Univ. of Minnesota, 1991 Buford Circle, St. Paul, MN 55108. Paper no. 3033 from the Laboratory of Genetics. Research supported by the College of Agric. and Life Sciences, Int. Potato Ctr., USDA-CRGO-88-37234-3619, and Frito-Lay, Inc.
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