Different genetic markers of diversity decline at different rates, creating an imbalance.
The relevance of these loci as markers of diversity was verified (Technical Appendix 3).
Together, these and other studies indicate that some allozyme loci are not neutral markers of diversity, but rather that the geographic distributions of alleles can be a consequence of environmental conditions and the differential performance of alleles in those environments.
One photographer, in the placard below her painting, is pleased to see them as a marker of diversity; another just says she loves them.
While the "openness" of the pangenome is an obvious marker of diversity, sequence heterogeneity within the core gene set has also been shown to be relevant to natural genetic variation [ 8- 10].
Terminase [ 11] and portal [ 12] proteins were further described as potential markers of phage diversity, as well as tape measure proteins in long-tail bacteriophages [ 13].
Thiel et al [ 24] have stressed the limitations surrounding the application of SSR markers for diversity studies, emphasising the possibility of homoplasy (identical allele sizes may not be identical by descent), and have pointed out that allele size differences can also be generated by indel events, as well as by variation in the SSR repeat number.
High resolution mapping of these genotypes using a large number of genomic markers for diversity analysis may provide different results because genic-SSRs represent the transcribed portion of the genome, while the repetitive heterochromatin portion of the genome plays a major role in the evolution of species [ 54].
Typically, a plateau of accuracy is reached with a few hundred markers for bi-parental populations [ 39, 51, 52] and with a couple of thousand markers for diversity panels [ 53, 54].
The potential usefulness of SSR markers for diversity and phylogenetic studies in Apiaceae will depend, to a great extent, on the possibility that markers successfully amplify across different species and on the ability of the marker to detect polymorphism among the taxa.
The sequence polymorphism analysis program, DnaSP, confirmed that substantially fewer SNPs were detected in most of the conserved genes compared to the variable genes, with the θG value an excellent marker of genetic diversity.
