Genetic Resources and Crop Evolution

, Volume 54, Issue 4, pp 837–848 | Cite as

Capturing genetic diversity of wild populations for ex situ conservation: Texas wild rice (Zizania texana) as a model

  • Christopher M. Richards
  • Michael F. Antolin
  • Ann Reilley
  • Jackie Poole
  • Christina Walters
Original Paper

Abstract

Genebanks complement other conservation programs because they preserve genetic diversity needed for future breeding and restoration. We evaluated efficiency of capturing genetic diversity, using endangered Zizania texana (Texas wild rice) as a model for plants with recalcitrant seeds. This perennial aquatic grass is restricted to 4 km of the San Marcos River in Texas. An early conservation collection included plants from stands throughout the river, based on the assumption stands would be unique genotypes. Using microsatellite markers, we found that genetic diversity was concentrated in five of 15 large, demographically stable stands; 96 stands smaller than 2 m2 contributed no unique alleles. High heterozygosity and few duplicate genotypes suggested that sexual reproduction occurs more often than presumed. Simulations of stratified sampling of large stands captured all alleles in only 45 individuals, while random sampling along the river captured much less diversity. The early conservation collection captured as much diversity as expected from random sampling. Texas wild rice stands resemble a mainland-island metapopulation; our analyses suggest that stratified sampling maximizes genetic diversity for this population dynamic. Demographic and genetic information is important for validating the design of efficient ex situ collections and guiding in situ conservation.

Key words

Stratified sampling Allelic richness Conservation genetics Genetic structure Zizania texana 

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Copyright information

© Springer Science+Business Media, Inc. 2006

Authors and Affiliations

  • Christopher M. Richards
    • 1
  • Michael F. Antolin
    • 2
  • Ann Reilley
    • 1
  • Jackie Poole
    • 3
  • Christina Walters
    • 1
  1. 1.USDA/ARS National Center for Genetic Resources PreservationFort CollinsUSA
  2. 2.Department of BiologyColorado State UniversityFort CollinsUSA
  3. 3.Texas Parks & WildlifeAustinUSA

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