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Title: DIFFUSION OF POTATO GERMPLASM AND MODERN BREEDING

Author
item Brown, Charles

Submitted to: Environmental Concerns with Transgenic Plants in Latin America Potato as A
Publication Type: Proceedings
Publication Acceptance Date: 5/30/1995
Publication Date: N/A
Citation: N/A

Interpretive Summary: Society is concerned that crop plants that have genetically engineered genes pose potential risks. One of the risks is that the genes will move into wild relatives and that this will cause an ecological disturbance because the presence of the genes might make the wild species become a pest. The risk of gene escape in Mexico, Central and South America presents a special challenge, as these are the only areas of the world where cultivated potato comes into contact with an abundant, highly diverse, and, often, highly crossable wild potato flora. Therefore, it is likely these genes will find their way into wild potato populations sooner or later. This chapter points out that genes with potentially large impact have migrated from wild species to cultivated potato over the years due to the efforts of man to breed superior potato varieties. Many disease and pest traits from wild relatives are present in modern varieties. Although the changes have been beneficial in reducing crop loss, the genes have not led to the conversion of cultivated potato into a weedy pest in any way. It is debatable, therefore, whether genes that are the result of genetic engineering would cause important differences in the growth pattern or adaptation of wild species. The main conclusions are that: 1) the genetically engineered genes will eventually be transferred to wild species; and 2) there is no specific adverse result we can identify as likely to occur as a result of this transfer. The fear that superpest wild potato will arise is unfounded.

Technical Abstract: This paper reviews the history of potatoes as a crop and the current trends for development of transgenic potatoes. The potato began its journey from its center of origin as an unappreciated and alien plant. Acceptance was slow to develop and almost certainly involved genetic change from the form in which it was originally introduced. It was adopted as a food of the masses, providing a reliable and usually highly productive food source. Infusions of genes from the center of origin remained rare and mostly ineffectual until the twentieth century. Our knowledge of potato and its relatives in its original habitat remained as impoverished as potato's actual genetic diversity over several centuries. In the last half century, a rich understanding has developed of the biodiversity of native potato cultivars and wild species, categories which encompass thousands of genetically unique entities. Today, the potato continues to be enhanced by yextensive use of plant introductions in breeding of new varieties. Gene insertion offers new opportunities to develop varieties will fit into a particular market niche. It has yet to be seen whether gene insertion is a major revolution or a valuable adjunct to traditional breeding. Experience teaches us that we have much left to learn and, hopefully, much benefit to reap in the future.