Shawn K Thomas1,2, Xiang Liu3,4, Zhi-Yuan Du5, Yibo Dong3,6, Amanda Cummings1, Lisa Pokorny7,8, Qui-Yun Jenny Xiang3, James H Leebens-Mack1. 1. Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA. 2. Division of Biological Sciences, University of Missouri, Columbia, MO, 65203, USA. 3. Department of Plant and Microbial Biology, North Carolina State University, Raleigh, NC, 27695, USA. 4. Syngenta, Research Triangle Park, NC, 27709, USA. 5. Wuhan Botanical Garden, The Chinese Academy of Sciences, Wuhan, Hubei, 430074, China. 6. Global Health Infectious Disease Research, College of Public Health, University of South Florida, Tampa, FL, 33612, USA. 7. Royal Botanic Gardens, Kew, Richmond, London, TW9 3AE, UK. 8. Computational/Systems Biology and Genomics Program, Centre for Plant Biotechnology and Genomics, UPM-INIA-CSIC, Pozuelo de Alarcón (Madrid), 28223, Spain.
Abstract
PREMISE: Cornales is an order of flowering plants containing ecologically and horticulturally important families, including Cornaceae (dogwoods) and Hydrangeaceae (hydrangeas), among others. While many relationships in Cornales are strongly supported by previous studies, some uncertainty remains with regards to the placement of Hydrostachyaceae and to relationships among families in Cornales and within Cornaceae. Here we analyzed hundreds of nuclear loci to test published phylogenetic hypotheses and estimated a robust species tree for Cornales. METHODS: Using the Angiosperms353 probe set and existing data sets, we generated phylogenomic data for 158 samples, representing all families in the Cornales, with intensive sampling in the Cornaceae. RESULTS: We curated an average of 312 genes per sample, constructed maximum likelihood gene trees, and inferred a species tree using the summary approach implemented in ASTRAL-III, a method statistically consistent with the multispecies coalescent model. CONCLUSIONS: The species tree we constructed generally shows high support values and a high degree of concordance among individual nuclear gene trees. Relationships among families are largely congruent with previous molecular studies, except for the placement of the nyssoids and the Grubbiaceae-Curtisiaceae clades. Furthermore, we were able to place Hydrostachyaceae within Cornales, and within Cornaceae, the monophyly of known morphogroups was well supported. However, patterns of gene tree discordance suggest potential ancient reticulation, gene flow, and/or ILS in the Hydrostachyaceae lineage and the early diversification of Cornus. Our findings reveal new insights into the diversification process across Cornales and demonstrate the utility of the Angiosperms353 probe set.
PREMISE: Cornales is an order of flowering plants containing ecologically and horticulturally important families, including Cornaceae (dogwoods) and Hydrangeaceae (hydrangeas), among others. While many relationships in Cornales are strongly supported by previous studies, some uncertainty remains with regards to the placement of Hydrostachyaceae and to relationships among families in Cornales and within Cornaceae. Here we analyzed hundreds of nuclear loci to test published phylogenetic hypotheses and estimated a robust species tree for Cornales. METHODS: Using the Angiosperms353 probe set and existing data sets, we generated phylogenomic data for 158 samples, representing all families in the Cornales, with intensive sampling in the Cornaceae. RESULTS: We curated an average of 312 genes per sample, constructed maximum likelihood gene trees, and inferred a species tree using the summary approach implemented in ASTRAL-III, a method statistically consistent with the multispecies coalescent model. CONCLUSIONS: The species tree we constructed generally shows high support values and a high degree of concordance among individual nuclear gene trees. Relationships among families are largely congruent with previous molecular studies, except for the placement of the nyssoids and the Grubbiaceae-Curtisiaceae clades. Furthermore, we were able to place Hydrostachyaceae within Cornales, and within Cornaceae, the monophyly of known morphogroups was well supported. However, patterns of gene tree discordance suggest potential ancient reticulation, gene flow, and/or ILS in the Hydrostachyaceae lineage and the early diversification of Cornus. Our findings reveal new insights into the diversification process across Cornales and demonstrate the utility of the Angiosperms353 probe set.
Authors: Ana Rita G Simões; Lauren A Eserman; Alexandre R Zuntini; Lars W Chatrou; Timothy M A Utteridge; Olivier Maurin; Saba Rokni; Shyamali Roy; Félix Forest; William J Baker; Saša Stefanović Journal: Front Plant Sci Date: 2022-07-14 Impact factor: 6.627