Molecular recircumscription of Broussonetia (Moraceae) and the identity and taxonomic status of B. kaempferi var. australis

Abstract

BackgroundDespite being a relatively small genus, the taxonomy of the paper mulberry genus Broussonetia remains problematic. Much of the controversy is related to the identity and taxonomic status of Broussonetia kaempferi var. australis, a name treated as a synonym in the floras of Taiwan and yet accepted in the floras of China. At the generic level, the monophyly of Corner (Gard Bull Singap 19:187–252, 1962)’s concept of Broussonetia has not been tested. In recent studies of Broussonetia of Japan, lectotypes of the genus were designated and three species (B. kaempferi, Broussonetia monoica, and Broussonetia papyrifera) and a hybrid (B. ×kazinoki) were recognized. Based on the revision and molecular phylogenetic analyses, this article aims to clarify these issues.ResultsHerbarium studies, field work, and molecular phylogenetic analyses indicate that all Taiwanese materials identifiable to B. kaempferi var. australis are conspecific with B. monoica of Japan and China. Molecular phylogenetic analyses showed that Broussonetia sensu Corner (Gard Bull Singap 19:187–252, 1962) contains two clades corresponding to sect. Broussonetia and sect. Allaeanthus, with Malaisia scandens sister to sect. Broussonetia.ConclusionsBased on our analyses, B. kaempferi var. australis is treated as a synonym of B. monoica and that B. kaempferi is not distributed in Taiwan. To correct the non-monophyly of Broussonetia sensu Corner (Gard Bull Singap 19:187–252, 1962), Broussonetia is recircumscribed to contain only sect. Broussonetia and the generic status of Allaeanthus is reinstated.Electronic supplementary materialThe online version of this article (doi:10.1186/s40529-017-0165-y) contains supplementary material, which is available to authorized users.

Long-distance dispersal shaped the diversity of tribe Dorstenieae (Moraceae)

“…In this study, we follow the classification of Clement & Weiblen (2009) with modifications based on Zerega et al (2010, recommending Treculia be transferred to Dorstenieae) and Chung et al (2017, reinstating Allaeanthus in Dorstenieae). This approach recognizes fifteen genera and approximately 153 species in this tribe (Table 1).…”

“…We reconstructed phylogenetic relationships using both a concatenated maximum likelihood (ML) and a coalescent approach. Milicia exceisa and Artocarpus venenosus were specified as the most external outgroups based on recent phylogenetic analyses of Moraceae (Clement & Weiblen, 2009; Zerega et al, 2010; Chung et al, 2017; Gardner et al, 2017; Zhang et al, 2018). Sequences were concatenated into a supermatrix and partitioned according to genes using the fasta_merge.py script from HybPiper; a ML tree was reconstructed with RAxML v8.2.10 (Stamatakis, 2014) as implemented on CIPRES (Miller et al, 2010) 1000 rapid bootstrap replicates.…”

“…(incl. Allaeanthus , previously included in Broussonetia , and Malaisia ; Chung et al, 2017) to a minimum age of 33.9 Ma. The fossil achenes of Ficus ( F. lucidus Chandler) (Chandler, 1962) were used to calibrate the stem group of Ficus with a minimum age of 56.0 Ma.…”

“…Distribution data for the taxa sampled were collected from monographs and revisions (Rohwer & Berg, 1993; Berg & Hijman, 1999; Berg, 2001; Chung et al, 2017). We separated the distribution area of extant species of Dorstenieae into six areas (Figure 1) following a recent study of Annonaceae, which share a similar global distribution (Couvreur et al, 2011): A, South America; B, North/Central America; C, Africa; D, Madagascar; E, India and Sri Lanka; F, Southeast Asia and Oceania.…”

“…The generic composition of the angiosperm tribe Dorstenieae in the Moraceae family has been under recent scrutiny. Based on taxonomic treatments and recent molecular phylogenetic studies, Dorstenieae are currently thought to consist of fifteen genera (Table 1) and approximately 156 species (Berg et al 2001; Clement & Weiblen 2009; Zerega et al 2010; Chung et al 2017). The most diverse genus in Dorstenieae is Dorstenia , which includes 113 species (Berg & Hijman, 1999; Mccoy & Massara, 2008; dos Santos & Neto, 2012; Machado & Marcelo Filho, 2012; Chase et al, 2013; dos Santos et al, 2013; Leal, 2014; Machado et al, 2014; Rzepecky, 2016).…”