Submitted to: Crop Science
Publication Type: Peer reviewed journal
Publication Acceptance Date: 6/20/2003
Publication Date: 3/1/2004
Citation: Mosjidis, J.A., Greene, S.L., Klingler, K.A., Afonin, A. 0200. Isozyme diversity in wild red clover populations from the caucasus. Crop Science. 44:665-670 Interpretive Summary: This paper describes research to characterize the genetic diversity of wild red clover populations that were collected in the Caucasus Mountains in 1995. Isozymes were used in the study. What we found was that the red clover populations were very diverse, and their diversity corresponded closely with our expectations of gene flow, based on the topographical features of the landscape, as characterized by geographic information interpolated from remotely sensed sources.
Technical Abstract: Red clover (Trifolium pratense L.) is one of the most important forage species. The amount of genetic variation within species and populations and the distribution of genetic diversity (GD) among populations is important to breeders and biologists. The objective of this study was to assess GD in 15 wild red clover populations collected in the Caucasus Mountains, Russia, based on isozymes. Isozymes assayed were esterase, ?-glucosidase, phosphoglucomutase, peroxidase, diaphorase, phosphoglucoisomerase, and superoxide dismutase. Ten isozyme loci with 26 alleles were detected. Ninety percent of the loci were polymorphic in at least one population. Percent polymorphic loci within populations ranged between 50 and 90%. At the species level, the number of alleles per polymorphic locus was 2.89 and effective number of alleles per locus was 1.84. Within-population averages were 2.75 and 1.70, respectively. Genetic diversity was 0.353 at the species level and the mean value for the populations was 0.323. Most populations were found to be unique at the isozyme level. Furthermore, some populations were particularly different from the others. This warrants the inclusion of the populations in the red clover collection held by NPGS. Diversity measurements indicated that this species has a high level of variability that resides mostly within populations. Gene flow expectations based on predictions using topographic maps developed using interpolated digital and climatic surfaces coincided with gene flow estimates obtained using isozymes. This supports the use of GIS tools and remotely sensed data to develop maps that help germplasm collection and post-collection efforts to understand patterns of GD in collected germplasm.