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Echinacea is a North American medicinal plant that was used for medicinal purposes by Native Americans. Modern uses of Echinacea preparations include the treatment of colds and influenza, wound healing, and treatment of candidiasis. While demand is increasing, the natural populations of Echinacea are dwindling due to wild crafting and the loss of habitat caused by urban development. Understanding of the genetic diversity of natural populations is crucial in the management and conservation of the natural populations of Echinacea. Genetic diversity of natural populations of Echinacea was estimated using AFLP markers. Population genetic analysis of the AFLP data put the variation at 40% among and within the populations. Canonical analysis supported the four species concept of the morphometric analyses, however phylogenetic analysis supported some of the four species, but there was very little support by all the other analyses of the eight varieties of Echinacea. No correlations were found between the genetic distances and the geographic distances at the population level. The correlations between data sets and primer pairs was high at the species level, but was lower at the variety level. AFLP markers that were species or variety specific could not be identified. The comigrating bands that are monomorphic within and among species and varieties are 90% identical in their nucleotide sequences while the polymorphic bands within and among species and varieties are only 25% identical. The assumption that comigrating AFLP fragments have identical sequences within species and varieties is not valid in Echinacea. Based on these findings, AFLP markers were treated as phenotypes rather than genotypes and as such used for phylogenetic analysis of Echinacea populations. Phylogenetic analysis supported only two species, E. purpurea and E. laevigata that separated into clear groups with all the individuals together, whereas E. atrorubens and E. pallida were separated into groups, but the individuals were scattered among the groups. The varieties could not be grouped, as the individuals were scattered among different groups. However discriminant analysis of the AFLP data revealed bands that could be used to identify the four species and only three of the eight varieties Echinacea. Tissue culture procedures for mass propagation of Echinacea purpurea (L.) Moench for producing uniform plants from leaves of mature plants were established. However, the method was not applicable for all the other species and varieties of Echinacea. |
