Interfamilial relationships in order Fabales: new insights from the nuclear regions sqd1 and 26S rDNA

• Published in: Plant systematics and evolution Vol. 306; no. 4
• Main Authors: Aygoren Uluer, Deniz, Hawkins, Julie A., Forest, Félix
• Format: Journal Article
• Language: English
• Published: Vienna Springer Vienna 01.08.2020; Springer Nature B.V
• Subjects: Bayesian analysis; Biomedical and Life Sciences; Fabales; Leguminosae; Life Sciences; Original Article; Phylogenetics; Phylogeny; Plant Anatomy/Development; Plant Ecology; Plant Sciences; Plant Systematics/Taxonomy/Biogeography; Polygalaceae; Statistical inference; Surianaceae; Topology; 1; Quillajaceae; Surianaceae; Leguminosae; Polygalaceae; K; L; Fabales; 26S
• ISSN: 0378-2697; 1615-6110; 2199-6881
• DOI: 10.1007/s00606-020-01691-7

Leguminosae, Polygalaceae, Quillajaceae and Surianaceae together comprise the order Fabales. Phylogenetic relationships within Fabales remain an unsolved problem even though interfamilial relationships have been examined in a number of studies using different sampling approaches and both molecular and morphological data. In this study, we gather information from the nuclear 26S rDNA region as well as previously published data from the sqd 1 , mat K and rbc L regions. Phylogenetic analyses were performed by maximum parsimony, maximum likelihood and Bayesian inference. Overall, the best-supported topology for the relationships among families within the order places the pair of Leguminosae and Polygalaceae as sister to the pair of Quillajaceae and Surianaceae. However, our approximately unbiased (AU) test of the combined data results has shown that none of the seven different topologies rejected. Furthermore, three topologies were not significantly different from each other. Therefore, similar to the previous studies, this study did not find well-supported dichotomous relationships among the four Fabales families. The Fabales topology was very sensitive to both data choice and the phylogenetic methods used, which may indicate a rapid-near-simultaneous evolution of the four Fabales families. Our results also show that while nuclear sqd 1 can be helpful as a complementary region, both the nuclear sqd 1 and rDNA 26S regions could be problematic when analyzed individually.