Introgression Among Three Western North American Bilberries (Vaccinium section Myrtillus)

Abstract

Abstract—Despite being dominant elements of understory communities in the coniferous forests of western North America, phylogenetic relationships among bilberries (Vaccinium section Myrtillus) remain unresolved. Morphological delimitation among most western bilberry species is tenuous, and traditionally employed molecular sources of phylogenetic information have yielded insufficient variability. Moreover, these species are hypothesized to have undergone extensive introgression. We used RADseq data analyzed with maximum likelihood species tree estimation and Patterson’s D-statistic analyses to examine the influence of introgression on relationships among Vaccinium myrtillus, V. scoparium, and V. cespitosum. Additionally, we used these data to assess whether the populations of V. myrtillus disjunct between North America and Eurasia are monophyletic and should continue to be recognized as conspecific. Significant genome-wide introgression, as determined through D-statistic analyses, was detected between North American samples of V. myrtillus and V. cespitosum, and to a lesser extent, between V. myrtillus and V. scoparium. No significant D-values were detected between V. scoparium and V. cespitosum. Accessions of Vaccinium myrtillus from Eurasia and North America were recovered as non-monophyletic, prompting our proposed resurrection of V. oreophilum for North American material. The long-assumed sister species relationship between V. oreophilum and V. scoparium was not recovered in our analysis. Instead, V. oreophilum and V. cespitosum were inferred to be sister taxa. This study reveals considerable introgression detectable in the evolutionary history of western North American bilberries and demonstrates the utility of RADseq data to resolve species level relationships in groups that undergo reticulate evolution such as Vaccinium.

Unveiling the evolutionary history of lingonberry (Vaccinium vitis-idaeaL.) through genome sequencing and assembly of European and North American subspecies

“…Although further analysis is required to fully understand the relationship, it implies that Vaccinium has high levels of incomplete lineage sorting or possibly introgression between species (Coyne and Orr 2004; Beeler et al . 2020).…”

Phylogeny and revised classification of New World Ruellia

“…Next‐gen sequence data presented herein yield a phylogenetic framework that is, for the most part, both robust and well‐resolved, reflecting success of RADseq methods in numerous other recent studies of Acanthaceae that have emphasized species‐level relationships (e.g., Petalidium [Tripp & al., 2017]; Louteridium [Daniel & Tripp, 2018]; Barleria [Comito & al., 2022]; Justicia [Kiel & al., in prep. ]; Monechma [Darbyshire & al., 2020]; multiple genera of Ruellieae [Tripp & Darbyshire, 2020]) as well as in other families of plants and lichens ( Stellaria [Sharples & Tripp, 2019a,b]; Vaccinium [Beeler & al., 2020]; Cladonia [Anderson Stewart & Manzitto‐Tripp, in prep.]). Specifically, the 15 sections of NW Ruellia delimited in this study are each strongly supported by BS values ≥81%.…”

Demographic responses of hybridizing cinquefoils to changing climate in the Colorado Rocky Mountains

“…Leaflets of tagged individuals (from the demographic study -see Section 2) were collected on silica gel, freeze-dried, homogenized, and DNA extracted using DNeasy plant mini kits (Qiagen). A double-digest RADseq library using EcoR1 and Mse1 restriction enzymes was prepared and sequenced following (Beeler et al, 2020;Tripp et al, 2017). Blue pippin size selection and sequencing were performed at the Biofrontiers Sequencing Facility at the University of Colorado.…”

“…Blue pippin size selection and sequencing were performed at the Biofrontiers Sequencing Facility at the University of Colorado. We used iPYRAD to filter, clean, and demultiplex the data (Beeler et al, 2020;Eaton & Overcast, 2020) and we performed a Principal Components Analysis using the Variant Call Format (VCF) table output to examine sequence variation among parent and putative hybrid taxa. (columns; 2019, 2020).…”