Data from: Weaving a tangled web: divergent and reticulate speciation in Boechera fendleri sensu lato (Brassicaceae: Boechereae)

Hybrid speciation is relatively common in plants compared to other
well-studied groups. Polyploidy and apomixis are strongly associated with
hybrid speciation, presumably due to the opportunities they provide for
both reestablishing reproductive function in hybrids with incomplete
chromosomal homology and creating rapid reproductive isolation in
sympatry. Boechera, a species-rich genus closely related to Arabidopsis,
is a particularly fertile ground for the study of hybrid speciation.
Thirty-eight apomictic triploid hybrid species are currently recognized in
Boechera. Recent research has shown that apomictic diploid hybrids,
although very rare in angiosperms, are common in Boechera. Given this
complexity, focused studies of individual species complexes are critical
to understanding speciation and diagnosing biodiversity in Boechera. Here
we analyze DNA sequences from seven nuclear loci and multilocus genotypes
from 15 microsatellite markers in a group of closely related taxa formerly
included in B. fendleri. Our results support the recognition of four
species previously segregated from B. fendleri s. l., including three
genetically distinct, sexual diploids (B. fendleri, B. spatifolia, and B.
texana) and one apomictic triploid hybrid (B. porphyrea). We also identify
four novel apomictic diploid hybrid species (B. carrizozoensis, B.
centrifendleri, B. sanluisensis, and B. zephyra) and additional apomictic
triploid hybrids. Our results reveal a complex network of relationships.
Sexual diploid species can hybridize to form apomictic diploids, and
members of these two groups can hybridize to form trigenomic, apomictic
triploids.