Charles Heiser Special Contributed Paper Session
Emshwiller, Eve , Epperson, Bryan , Theim, Terra , Tay, David , Medina, Tulio .
Geographic Distribution of Genetic Diversity of Clonally Propagated Crops: Oxalis tuberosa as an example.
In both ex-situ and in-situ conservation frameworks, vegetatively-propagated (clonal) crops differ from seed-propagated crops in their conservation needs. Understanding of how crop diversity is distributed geographically is critical for conservation of that diversity, and it can be improved by incorporating GIS techniques, spatial statistics and new methods developed in landscape genetics. We studied the Andean tuber crop "oca," Oxalis tuberosa, as a model for the evolution of clonally-propagated crops under human influence, specifically how the exchange of planting material among farmers determines the distribution of clonal genotypes in traditional Andean agriculture. We conducted spatial statistical analyses of oca to study how human-mediated dispersal affects the genetic structure of clonal crop populations, and what factors influence the amount of exchange among areas. Cultivated oca was sampled from carefully-distributed localities throughout the Peruvian Andes, and samples were subsequently cultivated in a highland experiment station of INIA (Instituto Nacional de InnovaciÃ³n Agraria) for morphological and molecular analyses. Spatial statistical analyses of AFLP data of 954 oca individuals from 38 localities were done for both individual AFLP alleles and clonal genotypes, the latter determined by both AFLP and morphological data. Importantly, our results found that many oca clonal genotypes have very restricted geographic distributions; most were found in only four or fewer communities. Only a few clonal genotypes were found in widely scattered, discontinuous areas, whereas most were restricted to a particular area in Peru. Our initial spatial autocorrelation analyses (Moran's I and join-count) yielded many very strong but unusual patterns across both spatial scales and genotypes. Wombling analyses of clones and of AFLP alleles also show strong patterns associated with major topographic barriers and linguistic boundaries. These findings have important conservation implications, not only because the clones are so narrowly distributed, but also because they indicate that other factors besides geographic distance have shaped the distribution of genotypes.
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UW-Madison Botany Department
Forestry at MSU
International Potato Center
Instituto Nacional de Innovación Agraria, Peru
1 - University Of Wisconsin-Madison, Botany Dept, 321 Birge Hall, 430 Lincoln Drive, Madison, WI, 53706-1313, USA
2 - Michigan State University, 126 NATURAL RESOURCE BUILDING, East Lansing, MI, 48824-1222, USA
3 - University of Wisconsin - Madison, Botany Department, 430 LIncoln Dr, Madison, WI, 53706, USA
4 - Centro Internacional de La Papa, Av. La Molina 1895, La Molina,, Apartado 1558, Lima 12,, Lima, Peru
5 - Instituto Nacional de Innovación Agraria, Recursos Geneticos, Av. La Molina # 1981, La Molina,, Apartado Postal 2791,, Lima, Peru
plant genetic resources
Presentation Type: Oral Paper:Papers for Topics
Location: Lindell D/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 11:15 AM