Informal “Seed” Systems and the Management of Gene Flow in Traditional Agroecosystems: The Case of Cassava in Cauca, Colombia

Our ability to manage gene flow within traditional agroecosystems and their repercussions requires understanding the biology of crops, including farming practices' role in crop ecology. That these practices' effects on crop population genetics have not been quantified bespeaks lack of an appropriate...

Full description

Bibliographic Details
Main Authors: Dyer, G., González, C., Lopera, Diana Carolina
Format: Journal Article
Language:Inglés
Published: Public Library of Science 2011
Online Access:https://hdl.handle.net/10568/42478
_version_ 1855519864688476160
author Dyer, G.
González, C.
Lopera, Diana Carolina
author_browse Dyer, G.
González, C.
Lopera, Diana Carolina
author_facet Dyer, G.
González, C.
Lopera, Diana Carolina
author_sort Dyer, G.
collection Repository of Agricultural Research Outputs (CGSpace)
description Our ability to manage gene flow within traditional agroecosystems and their repercussions requires understanding the biology of crops, including farming practices' role in crop ecology. That these practices' effects on crop population genetics have not been quantified bespeaks lack of an appropriate analytical framework. We use a model that construes seed-management practices as part of a crop's demography to describe the dynamics of cassava (Manihot esculenta Crantz) in Cauca, Colombia. We quantify several management practices for cassava—the first estimates of their kind for a vegetatively-propagated crop—describe their demographic repercussions, and compare them to those of maize, a sexually-reproduced grain crop. We discuss the implications for gene flow, the conservation of cassava diversity, and the biosafety of vegetatively-propagated crops in centers of diversity. Cassava populations are surprisingly open and dynamic: farmers exchange germplasm across localities, particularly improved varieties, and distribute it among neighbors at extremely high rates vis-à-vis maize. This implies that a large portion of cassava populations consists of non-local germplasm, often grown in mixed stands with local varieties. Gene flow from this germplasm into local seed banks and gene pools via pollen has been documented, but its extent remains uncertain. In sum, cassava's biology and vegetative propagation might facilitate pre-release confinement of genetically-modified varieties, as expected, but simultaneously contribute to their diffusion across traditional agroecosystems if released. Genetically-modified cassava is unlikely to displace landraces or compromise their diversity; but rapid diffusion of improved germplasm and subsequent incorporation into cassava landraces, seed banks or wild populations could obstruct the tracking and eradication of deleterious transgenes. Attempts to regulate traditional farming practices to reduce the risks could compromise cassava populations' adaptive potential and ultimately prove ineffectual.
format Journal Article
id CGSpace42478
institution CGIAR Consortium
language Inglés
publishDate 2011
publishDateRange 2011
publishDateSort 2011
publisher Public Library of Science
publisherStr Public Library of Science
record_format dspace
spelling CGSpace424782024-10-25T07:54:52Z Informal “Seed” Systems and the Management of Gene Flow in Traditional Agroecosystems: The Case of Cassava in Cauca, Colombia Dyer, G. González, C. Lopera, Diana Carolina Our ability to manage gene flow within traditional agroecosystems and their repercussions requires understanding the biology of crops, including farming practices' role in crop ecology. That these practices' effects on crop population genetics have not been quantified bespeaks lack of an appropriate analytical framework. We use a model that construes seed-management practices as part of a crop's demography to describe the dynamics of cassava (Manihot esculenta Crantz) in Cauca, Colombia. We quantify several management practices for cassava—the first estimates of their kind for a vegetatively-propagated crop—describe their demographic repercussions, and compare them to those of maize, a sexually-reproduced grain crop. We discuss the implications for gene flow, the conservation of cassava diversity, and the biosafety of vegetatively-propagated crops in centers of diversity. Cassava populations are surprisingly open and dynamic: farmers exchange germplasm across localities, particularly improved varieties, and distribute it among neighbors at extremely high rates vis-à-vis maize. This implies that a large portion of cassava populations consists of non-local germplasm, often grown in mixed stands with local varieties. Gene flow from this germplasm into local seed banks and gene pools via pollen has been documented, but its extent remains uncertain. In sum, cassava's biology and vegetative propagation might facilitate pre-release confinement of genetically-modified varieties, as expected, but simultaneously contribute to their diffusion across traditional agroecosystems if released. Genetically-modified cassava is unlikely to displace landraces or compromise their diversity; but rapid diffusion of improved germplasm and subsequent incorporation into cassava landraces, seed banks or wild populations could obstruct the tracking and eradication of deleterious transgenes. Attempts to regulate traditional farming practices to reduce the risks could compromise cassava populations' adaptive potential and ultimately prove ineffectual. 2011 2014-09-24T07:58:02Z 2014-09-24T07:58:02Z Journal Article https://hdl.handle.net/10568/42478 en Open Access Public Library of Science Dyer GA, González C, Lopera DC (2011) Informal “Seed” Systems and the Management of Gene Flow in Traditional Agroecosystems: The Case of Cassava in Cauca, Colombia. PLoS ONE 6(12): e29067. doi:10.1371/journal.pone.0029067
spellingShingle Dyer, G.
González, C.
Lopera, Diana Carolina
Informal “Seed” Systems and the Management of Gene Flow in Traditional Agroecosystems: The Case of Cassava in Cauca, Colombia
title Informal “Seed” Systems and the Management of Gene Flow in Traditional Agroecosystems: The Case of Cassava in Cauca, Colombia
title_full Informal “Seed” Systems and the Management of Gene Flow in Traditional Agroecosystems: The Case of Cassava in Cauca, Colombia
title_fullStr Informal “Seed” Systems and the Management of Gene Flow in Traditional Agroecosystems: The Case of Cassava in Cauca, Colombia
title_full_unstemmed Informal “Seed” Systems and the Management of Gene Flow in Traditional Agroecosystems: The Case of Cassava in Cauca, Colombia
title_short Informal “Seed” Systems and the Management of Gene Flow in Traditional Agroecosystems: The Case of Cassava in Cauca, Colombia
title_sort informal seed systems and the management of gene flow in traditional agroecosystems the case of cassava in cauca colombia
url https://hdl.handle.net/10568/42478
work_keys_str_mv AT dyerg informalseedsystemsandthemanagementofgeneflowintraditionalagroecosystemsthecaseofcassavaincaucacolombia
AT gonzalezc informalseedsystemsandthemanagementofgeneflowintraditionalagroecosystemsthecaseofcassavaincaucacolombia
AT loperadianacarolina informalseedsystemsandthemanagementofgeneflowintraditionalagroecosystemsthecaseofcassavaincaucacolombia