Publications by authors named "John C Semple"
Article Synopsis
- The Index to Chromosome Numbers in Asteraceae database provides detailed karyological information on the Asteraceae family, continuously updated and now hosted at the National Bioscience Database Center.
- The study dives into the evolution of base chromosome numbers in Asteraceae, focusing on key phenomena such as polyploidy, dysploidy, and hybridization, noting an ancestral base chromosome number of x = 9 originating in Antarctica.
- Recent phylogenetic research incorporated chromosome numbers from the database, revealing that x = 10 became predominant in Africa during northward migration, while x = 19 emerged in North America, with significant episodes of dysploidy and hybridization throughout the
Premise: The phylogenetic relationships among the ca. 138 species of goldenrods (Solidago; Asteraceae) have been difficult to infer due to species richness, and shallow interspecific genetic divergences. This study aims to overcome these obstacles by combining extensive sampling of goldenrod herbarium specimens with the use of a custom Solidago hybrid-sequence capture probe set.
View Article and Find Full Text PDFPremise: Polyploidy may serve to contribute to range size if autopolyploid cytotypes are adapted to differing ecological conditions. This study aims to establish the geographic distribution of cytotypes within the giant goldenrod (Solidago gigantea), and to assess whether cytotypes exhibit differing ecological tolerances and morphology.
Methods: A range-wide set of 629 Solidago gigantea individuals was obtained through field collecting, sampling from herbarium specimens, and incorporating existing chromosome counts.
Premise Of The Study: The ability to conduct species delimitation and phylogeny reconstruction with genomic data sets obtained exclusively from herbarium specimens would rapidly enhance our knowledge of large, taxonomically contentious plant genera. In this study, the utility of genotyping by sequencing is assessed in the notoriously difficult genus Solidago (Asteraceae) by attempting to obtain an informative single-nucleotide polymorphism data set from a set of specimens collected between 1970 and 2010.
Methods: Reduced representation libraries were prepared and Illumina-sequenced from 95 Solidago herbarium specimen DNAs, and resulting reads were processed with the nonreference Universal Network-Enabled Analysis Kit (UNEAK) pipeline.
Premise Of The Study: Microsatellite primers were developed for studies of polyploid evolution, ecological genetics, conservation genetics, and species delimitation in the genus Solidago. •
Methods And Results: Illumina sequencing of a shotgun library from S. gigantea identified ca.