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Premise: A family‐specific probe set for sunflowers, Compositae‐1061, enables family‐wide phylogenomic studies and investigations at lower taxonomic levels, but may lack resolution at genus to species levels, especially in groups complicated by polyploidy and hybridization. Methods: We developed a Hyb‐Seq probe set, Compositae‐ParaLoss‐1272, that targets orthologous loci in Asteraceae. We tested its efficiency across the family by simulating target enrichment sequencing in silico. Additionally, we tested its effectiveness at lower taxonomic levels in the historically complex genus Packera. We performed Hyb‐Seq with Compositae‐ParaLoss‐1272 for 19 Packera taxa that were previously studied using Compositae‐1061. The resulting sequences from each probe set, plus a combination of both, were used to generate phylogenies, compare topologies, and assess node support. Results: We report that Compositae‐ParaLoss‐1272 captured loci across all tested Asteraceae members, had less gene tree discordance, and retained longer loci than Compositae‐1061. Most notably, Compositae‐ParaLoss‐1272 recovered substantially fewer paralogous sequences than Compositae‐1061, with only ~5% of the recovered loci reporting as paralogous, compared to ~59% with Compositae‐1061. Discussion: Given the complexity of plant evolutionary histories, assigning orthology for phylogenomic analyses will continue to be challenging. However, we anticipate Compositae‐ParaLoss‐1272 will provide improved resolution and utility for studies of complex groups and lower taxonomic levels in the sunflower family. [ABSTRACT FROM AUTHOR]

Determining population genetic structure of isolated or fragmented species is of critical importance when planning a conservation strategy. Knowledge of the genetic composition and differentiation among populations of a rare or threatened species can aid conservation managers in understanding how, and which, populations to protect. The whorled sunflower, Helianthus verticillatus (Asteraceae), is a federally endangered sunflower species endemic to the southeastern United States. The distribution of the species comprises four known populations within three states: Alabama, Tennessee, and Georgia. Recently, new populations were discovered in Marshall County, Mississippi, and Franklin County, Virginia. Here, we carry out a population genetic study of these new populations using nuclear microsatellite markers and compare our results to those from previously known populations of H. verticillatus. Our results show that both newly discovered populations contain novel genetic variation, with Mississippi containing the most private alleles out of all populations tested. The Virginia population is genetically similar to the previously known populations but is under the most conservation concern given the recovery of only two unique genetic individuals found in this population. These results indicate these new populations are worthy of protection and conservation efforts given the unique genetic variation they harbor. [ABSTRACT FROM AUTHOR]

The megadiverse plant family Asteraceae forms an iconic component of island floras including many spectacular radiations, but a global picture of its insular diversity is lacking. Here, we uncover the global biogeographical and evolutionary patterns of Asteraceae on islands to reveal the magnitude and potential causes of their evolutionary success. We compile a global checklist of Asteraceae species native and endemic to islands and combine it with macroecological analyses and a phylogenetic review of island radiations. Asteraceae have a global distribution on islands, comprising approximately 6,000 native island species, with 58% endemics. While diversity of the family on islands is lower than expected given its overall diversity, Asteraceae are the most diverse family on oceanic islands, suggesting an exceptional ability to thrive in isolation. In agreement with island biogeography predictions, native Asteraceae diversity increases with area and decreases with isolation, while endemism increases with both. We identify 39 confirmed island radiations and 69 putative radiations, exceeding numbers for other iconic insular groups. Our results reveal Asteraceae offer immense potential for research in ecology and evolution, given their close tracking of island biogeography expectations, large number of both species and radiations, cosmopolitan distribution, and numerous undiscovered radiations., (© 2024. The Author(s).)