Data from: Next generation lineage discovery: a case study of tuberous Claytonia L.

PREMISE OF THE STUDY: Species formation is an intuitive endpoint of
reproductive isolation, but circumscribing taxa that arise during
speciation can be difficult because of gene flow, morphological
continuity, hybridization or polyploidization, and low sequence variation
among newly diverged lineages. Nonetheless, species complexes are
ubiquitous and their classification is essential for understanding how
diversity influences ecosystem function. METHODS: We used modern
sequencing technology to identify lineages of perennial Claytonia L., and
assessed correspondence between genetic lineages and
morphological/ecological variation. Subsets of 18 taxa from 63 populations
were used for (a) lineage discovery using network and coalescent analyses,
(b) leaf shape analyses using elliptical Fourier analysis and ordination,
and (c) ecological analyses (soil chemistry, climate) using ANOVA and
ordination. KEY RESULTS: Samples mainly aggregated into groups
representing each of the previously recognized species in each of the
genetic data sets. Compared to the double digest RADseq dataset, genome
skimming data provided more resolution and further opportunity to probe
into patterns of nuclear and chloroplast genome diversity. Morphological
and ecological associations are significantly different (albeit
intergrading) among the taxa investigated. A new species, Claytonia
crawfordii, is described based on morphological data presented here.
CONCLUSIONS: Genetic data presented in this study provide some of the
first insights into phylogenetic relationships among recently diverged
perennial Claytonia, and are suggestive of past hybridization among
caudicose and tuberous species. Given prior difficulties in understanding
species boundaries among newly diverged plant lineages, this case study
demonstrates the revolutionary breakthrough for systematics research that
high throughput sequencing represents.