Search

The aim of any reintroduction is to provide sufficient genetic variability to buffer against changing selection pressures and ensure long-term survival. To date, few empirical studies have compared levels of genetic diversity in reintroduced and native plant populations. Using microsatellite markers, we measured the genetic diversity within reintroduced and native populations of the threatened Cirsium pitcher (Eaton) Torrey and Gray. We found that the use of local mixed source was successful in establishing populations with significantly higher genetic diversity ( P < 0.005) than the native populations (allelic richness is 3.39 in reintroduced and 1.84 in native populations). However, the reintroduced populations had significantly higher inbreeding coefficients ( P < 0.002) ( FIS is 0.405 and 0.213 in reintroduced and in native populations, respectively), despite having multiple genetic founders, population sizes equivalent to native populations and a positive growth rate. These results may be due to inbreeding or the Wahlund effect, driven by genetic substructuring. This suggests that the small population size of these reintroduced populations may lead to genetic issues in the future, given the low number of flowering individuals each year. This highlights the importance of considering not only the number of source individuals but the effective population size of the reintroduction. [ABSTRACT FROM AUTHOR]

Copyright of Botany is the property of Canadian Science Publishing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Crop wild relatives (CWRs) are wild taxa with close genetic relationships to species with direct socioeconomic importance. As essential components of natural habitats and agricultural systems, their conservation and sustainable use are vital. CWRs are ex situ conserved in germplasm banks as samples of natural populations (accessions). Most accessions have been assigned specific status according to the Taxonomic Species Concept, which presupposes that living organisms are at the end of speciation. Thus, the morphological and genetic variability that could be encountered in natural populations is disregarded, negatively affecting conservation of allelic frequencies and effective use in breeding. Passport information usually contains collection date and geographical data, but not reproductive behavior of the sampled population (which defines its genetic structure) and sampling strategies. For ex situ multiplications of original collections, no information is provided on the effectively used strategies. As information on how accessions were composed is lacking, conservation of the allelic frequencies from the originally sampled populations is unknown. Knowledge of reproductive biology of plant populations is of utmost importance to understanding their natural morphological and molecular variability and to developing appropriate methodological approaches for sampling, classifying, and ex situ multiplying to conserve gene frequencies for basic and applied purposes. [ABSTRACT FROM AUTHOR]

Crop wild relatives (CWRs) are wild taxa with close genetic relationships to species with direct socioeconomic importance. As essential components of natural habitats and agricultural systems, their conservation and sustainable use are vital. CWRs are ex situ conserved in germplasm banks as samples of natural populations (accessions). Most accessions have been assigned specific status according to the Taxonomic Species Concept, which presupposes that living organisms are at the end of speciation. Thus, the morphological and genetic variability that could be encountered in natural populations is disregarded, negatively affecting conservation of allelic frequencies and effective use in breeding. Passport information usually contains collection date and geographical data, but not reproductive behavior of the sampled population (which defines its genetic structure) and sampling strategies. For ex situ multiplications of original collections, no information is provided on the effectively used strategies. As information on how accessions were composed is lacking, conservation of the allelic frequencies from the originally sampled populations is unknown. Knowledge of reproductive biology of plant populations is of utmost importance to understanding their natural morphological and molecular variability and to developing appropriate methodological approaches for sampling, classifying, and ex situ multiplying to conserve gene frequencies for basic and applied purposes. [ABSTRACT FROM AUTHOR]