Browsing by Author "Groppo, Milton"

Abstract Rutaceae is a family of angiosperms well known for the economically important genus Citrus. The division of Rutaceae into subfamilies is still inadequate and provisional. Previous phylogenetic studies at the family level are characterized by a limited sampling of genera and lack several crucial taxa. Here, we present a phylogenetic study based on six nuclear and plastid markers including 87.7% of the currently accepted genera, which is more than twice as many as in previous studies. Seven genera are included in a phylogenetic analysis for the first time. Most clades are resolved with high support, and we propose a new subfamily classification for Rutaceae that comprises the subfamilies Amyridoideae, Aurantioideae, Cneoroideae, Haplophylloideae, Rutoideae and Zanthoxyloideae. Aurantioideae is the only traditional subfamily that is resolved as monophyletic. We tested whether 13 morphological and karyological characters are taxonomically informative in Rutaceae. Chromosome numbers are clearly different in the two main clades of Rutaceae, but fruit characteristics, which have been used to define subfamilies in the past, do not distinguish between the main lineages of the family.

Sapindales is an angiosperm order of high economic and ecological value comprising nine families, c. 479 genera, and c. 6570 species. However, family and subfamily relationships in Sapindales remain unclear, making reconstruction of the order’s spatio-temporal and morphological evolution difficult. In this study, we used Angiosperms353 target capture data to generate the most densely sampled phylogenetic trees of Sapindales to date, with 448 samples and c. 85% of genera represented. The percentage of paralogous loci and allele divergence was characterized across the phylogeny, which was time-calibrated using 29 rigorously assessed fossil calibrations. All families were supported as monophyletic. Two core family clades subdivide the order, the first comprising Kirkiaceae, Burseraceae, and Anacardiaceae, the second comprising Simaroubaceae, Meliaceae, and Rutaceae. Kirkiaceae is sister to Burseraceae and Anacardiaceae, and, contrary to current understanding, Simaroubaceae is sister to Meliaceae and Rutaceae. Sapindaceae is placed with Nitrariaceae and Biebersteiniaceae as sister to the core Sapindales families, but the relationships between these families remain unclear, likely due to their rapid and ancient diversification. Sapindales families emerged in rapid succession, coincident with the climatic change of the Mid-Cretaceous Hothouse event. Subfamily and tribal relationships within the major families need revision, particularly in Sapindaceae, Rutaceae and Meliaceae. Much of the difficulty in reconstructing relationships at this level may be caused by the prevalence of paralogous loci, particularly in Meliaceae and Rutaceae, that are likely indicative of ancient gene duplication events such as hybridization and polyploidization playing a role in the evolutionary history of these families. This study provides key insights into factors that may affect phylogenetic reconstructions in Sapindales across multiple scales, and provides a state-of-the-art phylogenetic framework for further research.