Tribe Miliuseae Research Articles

Phylogenetic position of Miliusa vidalii (Miliuseae, Annonaceae) inferred from chloroplast DNA and morphology

A molecular phylogenetic study was conducted to determine the position of the Philippine endemic Miliusa vidalii in the tribe Miliuseae of family Annonaceae utilizing the combined cpDNA sequence data (trnL-F-matK-ndhF-psbA-trnH-ycf1). Bayesian inference and Maximum parsimony analyses revealed a robustly supported monophyletic Miliusa clade (PP=1.00; BS=93%). Miliusa vidalii nested within clade D (PP=1.00; BS=85%) shares similar features by having terminal inflorescences and a notably long pedicel. M. vidalii is resolved as sister to M. lanceolata, which shares morphological features such as length of pedicels, number of secondary veins, shape of leaf apex, and apiculate monocarp. This present study revealed that M. vidalii possesses a conspicuous glandular structure in the inner petals, a feature that is common only to species found in clade A. Therefore, increased taxon sampling is necessary to construct a stronger phylogenetic relationship within the genus.

GenusHuberantha(Annonaceae) Revisited: Erection ofPolyalthiopsis, a New Genus forH. floribunda, with a New CombinationH. luensis

The identity of an enigmatic species Huberantha floribunda (Annonaceae) is reassessed using molecular phylogenetic analyses of up to seven combined plastid markers (matK, ndhF, rbcL, ycf1 exons; trnL intron; trnL-trnF, psbA-trnH intergenic spacers), constituting up to ca. 7 kbp. Huberantha floribunda does not fall into Huberantha clade, but is retrieved as the sister group of Miliusa with no support, necessitating the recognition of a new genus, to accommodate this species. Polyalthiopsis Chaowasku gen. nov. along with Huberantha and Miliusa form an unsupported to weakly supported clade within the tribe Miliuseae. Morphology of Polyalthiopsis is somewhat intermediate between morphologies of Huberantha and Miliusa. It primarily differs from Huberantha by often possessing unequal petal whorls and a seed raphe that is broadly grooved and partially slightly raised in the middle. Polyalthiopsis differs from Miliusa mainly by having a dilated truncate connective apex of the stamens and outer petals that are much larger than the sepals. In addition, Huberantha luensis (Pierre) Chaowasku, a new combination for Polyalthia luensis is made based on an integrative approach of morphological examination coupled with molecular phylogenetic inferences.

A jungle tale: Molecular phylogeny and divergence time estimates of the Desmopsis-Stenanona clade (Annonaceae) in Mesoamerica

The predominantly Asian tribe Miliuseae (Annonaceae) includes over 37 Neotropical species that are mainly distributed across Mesoamerica, from southern Mexico to northern Colombia. The tremendous ecological and morphological diversity of this clade, including ramiflory, cauliflory, flagelliflory, and clonality, suggests adaptive radiation. Despite the spectacular phenotypic divergence of this clade, little is known about its phylogenetic and evolutionary history. In this study we used a nuclear DNA marker and seven chloroplast markers, and maximum parsimony, maximum likelihood and Bayesian inference methods to reconstruct a comprehensive time-calibrated phylogeny of tribe Miliuseae, especially focusing on the Desmopsis-Stenanona clade. We also perform ancestral area reconstructions to infer the biogeographic history of this group. Finally, we use ecological niche modeling, lineage distribution models, and niche overlap tests to assess whether geographic isolation and ecological specialization influenced the diversification of lineages within this clade. We reconstructed a monophyletic Miliuseae that is divided into two strongly supported clades: (i) a Sapranthus-Tridimeris clade and (ii) a Desmopsis-Stenanona clade. The colonization of the Neotropics and subsequent diversification of Neotropical Miliuseae seems to have been associated with the expansion of the boreotropical forests during the late Eocene and their subsequent fragmentation and southern displacement. Further speciation within Neotropical Miliuseae out of the Maya block seems to have occurred during the last 15 million years. Lastly, the geographic structuring of major lineages of the Desmopsis-Stenanona clade seems to have followed a climatic gradient, supporting the hypothesis that morphological differentiation between closely related species resulted from both long-term isolation between geographic ranges and adaptation to environmental conditions.

Electronic Supplement to: A new Annonaceae genus, Wuodendron, provides support for a post-boreotropical origin of the Asian-Neotropical disjunction in the tribe Miliuseae

Electronic Supplement to: A new Annonaceae genus, <i>Wuodendron</i>, provides support for a post-boreotropical origin of the Asian-Neotropical disjunction in the tribe Miliuseae

A new Annonaceae genus, Wuodendron, provides support for a post–boreotropical origin of the Asian–Neotropical disjunction in the tribe Miliuseae

AbstractRecent molecular and morphological studies have clarified generic circumscriptions in Annonaceae tribe Miliuseae and resulted in the segregation of disparate elements from the previously highly polyphyletic genus Polyalthia s.l. Several names in Polyalthia nevertheless remain unresolved, awaiting assignment to specific genera, including Polyalthia litseifolia. Phylogenetic analyses of seven chloroplast regions (atpB–rbcL, matK, ndhF, psbA–trnH, rbcL, trnL–F, ycf1; ca. 8.3 kb, 116 accessions, including representatives of all currently accepted genera in subfamily Malmeoideae) unambiguously placed Polyalthia litseifolia in a clade with three accessions from Thailand, which have previously been shown to represent an undescribed genus sister to the Neotropical clade (Desmopsis, Sapranthus, Stenanona, Tridimeris) in the predominantly Asian tribe Miliuseae. The collective clade is sister to Meiogyne. Polyalthia litseifolia shares several diagnostic characters with most species in the Neotropical genera and Meiogyne, including: petals that are similar in shape and size in both whorls; multiple ovules per ovary in one or two rows; and lamelliform endosperm ruminations. It is distinct in being deciduous, bearing subpetiolar buds and having inflorescences growing from the leaf scar of the dropped leaves. Morphological comparisons and phylogenetic analyses corroborate its recognition as a new genus, which is formally described and illustrated here as Wuodendron. Polyalthia litseifolia is furthermore found to be conspecific with Desmos praecox, and the latter name is used as the basis for the name of the type. Molecular divergence time estimates under an uncorrelated lognormal relaxed clock place the Wuodendron–Neotropical clade split within the Miocene (ca. 14–12 Ma), highlighting the importance of post–boreotropical dispersal and vicariance in shaping intercontinental tropical disjunctions in Annonaceae.

Miliusa sahyadrica, a new species of Annonaceae from the Western Ghats, India

Miliusa Leschenault ex A. de Candolle (1832: 213) is a Paleotropical genus in the family Annonaceae with about 60 species distributed mostly to the Austral-Asiatic region, ranging from India, Sri Lanka, Bhutan, Bangladesh, Myanmar, Thailand, Indonesia, Malay Islands, Philippines, Papua New Guinea to Australia and New Zealand (Mols &amp; Keßler 2003,Chaowasku &amp; Keßler 2013, Chaowasku et al. 2013). According to molecular phylogenetic analysis, the genus is placed in subfamily Malmeoideae, tribe Miliuseae (Chatrou et al. 2012). Thailand and India are considered as the centres of diversity for Miliusa with more than twenty species each (Mols &amp; Keßler 2003, Chaowasku &amp; Keßler 2013, Chaowasku et al. 2013, Turner 2015). A total of 23 species and one variety of the genus are so far recorded from India (Mitra 1993, Karthikeyan et al. 2009, Turner 2015, Page &amp; Nerlekar 2016, Page et al. 2016, Josekutty et al. 2016, Karuppusamy &amp; Richard 2016). Among these, 15 species and one variety are reported from the Western Ghats of India. Except for four species, namely M. indica Leschenault ex A. de Candolle (1832: 213), M. horsfieldii (Bennett 1840: 165) Pierre (1881: 38), M. tomentosa (Roxburgh: 1795: 31. t. 35.) Sinclair (1955: 378) and M. velutina (Dunal) Hooker &amp; Thomson (1855: 151), all are endemic to that region (Nayar et al. 2014). As a whole, the genus is phytogeographically significant to Western Ghats with 71% of the species being endemics, which makes the genus more important from conservation point of view.

The identity of Polyalthia florulenta (Annonaceae): a second species of Wangia in China

The taxonomic placement of Polyalthia florulenta C.Y.Wu ex P.T.Li has not been clarified. Phylogenetic analyses of eight chloroplast regions (matK, ndhF, ndhF-rpl32, psbA-trnH, rbcL, rpl32-trnL, trnL-F and ycf1; ca. 9.2 kb, 66 taxa) unambiguously placed Polyalthia florulenta in a subclade of tribe Miliuseae, sister to Wangia saccopetaloides. Polyalthia flourulenta shares several diagnostic characters with Wangia saccopetaloides, including leaf-opposed inflorescences, sepaloid outer petals and saccate inner petals with basal glandular tissue. It differs from Wangia saccopetaloides in having membranous leaf laminas, single-flowered inflorescences, subglobose single-seeded monocarps, and spiniform endosperm rumination. On the basis of the combined molecular phylogenetic and morphological data, we propose a new combination, Wangia florulenta (C.Y.Wu ex P.T.Li) B.Xue. As the protologue description was based on material lacking mature flowers, we provide a detailed description of flower morphology. A key to species in the genus Wangia is also provided.

A plastid DNA phylogeny of tribe Miliuseae: Insights into relationships and character evolution in one of the most recalcitrant major clades of Annonaceae

Tribe Miliuseae (∼25 genera and ∼510 species) includes a substantial part of the species and generic diversity in the pantropical flowering-plant family Annonaceae (∼108 genera and ∼2400 species). Previous molecular phylogenetic analyses have failed to resolve the backbone phylogeny of the tribe, impeding biogeographical and evolutionary studies. We use a dense generic taxon sample (∼89% of generic diversity in Miliuseae) and plastid DNA sequence data (∼7 kb) to clarify the phylogenetic relationships of and within the tribe. Parsimony and Bayesian phylogenetic reconstructions and ancestral character-state reconstructions of several reproductive characters were performed. Dendrokingstoniae, Monocarpieae, and Miliuseae are recovered in a strongly supported clade, and each tribe is strongly supported as monophyletic. Miliuseae are characterized by a synapomorphic cryptoaperturate/disulculate pollen apertural system. Stenanona is shown to be nested within the paraphyletic genus Desmopsis. The only Neotropical clade (Sapranthus, Tridimeris, Desmopsis, and Stenanona) in the predominantly Asian Miliuseae is shown to be closely related to an undescribed genus from continental Southeast Asia and the Indo-Malayan and Austral-Pacific genus Meiogyne. Ancestral character-state reconstructions of several reproductive characters that are diagnostically important at the generic level indicate a considerable degree of homoplasy. The results improve our understanding of the relationships of and within Miliuseae, but parts of the backbone of the phylogeny remain poorly supported. Additional data from variable nuclear markers or reduced-genome-representation approaches seem to be required to further resolve relationships within this recalcitrant clade.

Reassessing the taxonomic status of two enigmatic Desmos species (Annonaceae): Morphological and molecular phylogenetic support for a new genus, Wangia

The systematic position of two enigmatic Annonaceae species from China, Desmos saccopetaloides (W. T. Wang) P. T. Li and Desmos yunnanensis (Hu) P. T. Li, has been controversial, with both species having been transferred between several different genera within subfamilies Annonoideae and Malmeoideae. Phylogenetic analyses of eight chloroplast regions (matK, ndhF, ndhF-rpl32, psbA-trnH, rbcL, rpl32-trnL, trnL-F, and ycf1; ca. 9.2kb, 66 taxa) unambiguously placed D. saccopetaloides in a subclade of tribe Miliuseae, nested among the genera Monoon, Neo-uvaria, Phaeanthus, Sageraea, and Stelechocarpus. This relationship was also supported by endosperm rumination patterns in the seed; other morphological characters furthermore indicated that D. saccopetaloides has closer affinities with Monoon, Neo-uvaria, and Phaeanthus rather than either Sageraea or Stelechocarpus. Desmos saccopetaloides is distinguished from these genera by its leaf-opposed inflorescences, sepaloid outer petals, saccate inner petals with basal glandular tissue, moniliform monocarps with uniseriate seeds, and rectangular disulculate pollen with two cryptoapertures. On the basis of the combined molecular phylogenetic and morphological data, we propose a new genus, Wangia, to accommodate D. saccopetaloides. The molecular phylogenetic analyses furthermore indicated that D. yunnanensis belongs to the genus Dasymaschalon: examination of the type collections revealed that it is conspecific with Dasymaschalon obtusipetalum, although the combination Dasymaschalon yunnanense has nomenclatural priority.

&lt;p class="HeadingRunIn"&gt;&lt;strong&gt;Characterization of &lt;em&gt;Hubera&lt;/em&gt; (Annonaceae), a new genus segregated from &lt;em&gt;Polyalthia&lt;/em&gt; and allied to &lt;em&gt;Miliusa&lt;/em&gt;&lt;/strong&gt;&lt;/p&gt;

On the basis of molecular phylogenetics, pollen morphology and macromorphology, a new genus of the tribe Miliuseae, Hubera, segregrated from Polyalthia and allied to Miliusa, is established and described. It is characterized by the combination of reticulate tertiary venation of the leaves, axillary inflorescences, a single ovule per ovary and therefore single-seeded monocarps, seeds with a flat to slightly raised raphe, spiniform(-flattened peg) ruminations of the endosperm, and pollen with a finely and densely granular infratectum. Twenty-seven species are accordingly transferred to this new genus.

Evolution and phylogenetic significance of pollen in Annonaceae

The remarkable diversity of pollen morphology in Annonaceae has attracted systematic attention since the 1970s. Optimization of pollen characters on a molecular tree confirms that granular monosulcate pollen, as in Anaxagorea and subfamily Ambavioideae, was ancestral in the family. However, granular structure is derived for angiosperms as a whole, and exine characters are highly homoplastic in Annonaceae. Because columellar taxa (Annickia, Bocageeae) diverged earlier than previously thought, columellae may have re-originated in the common ancestor of Malmeoideae and Annonoideae, which make up most of the family, with several later reversals to granular structure. In Malmeoideae, loss of the sulcus and origin of a verrucate tectum occurred in the tribe Miliuseae, followed by an uncertain number of origins of disulculate pollen. Tetrads arose several times in Annonoideae, but reverted to monads in Isolona and probably Uvarieae. Recognition that microspores rotate during development in Annona and Cymbopetalum suggests that the proximal thin area in these taxa is a modified distal sulcus, but rotation does not occur in all tetrad groups; a broader survey is needed to evaluate this phenomenon. © 2012 The Linnean Society of London, Botanical Journal of the Linnean Society, 2012, 169, 190–221.

Pollen morphology of Miliusa and relatives (Annonaceae)

In order to provide additional data for the subdivision of the palaeotropical genus Miliusa (Annonaceae), its pollen was examined using light, scanning and transmission electron microscopy, including 20 of the 30 – 40 species. Further, species of the other genera in the former tribe Miliuseae (Alphonsea, Mezzettia, Orophea, Platymitra; Phoenicanthus not available) and of the Polyalthia cerasoides group, the sister group to Miliusa in a recent molecular analysis, were included. The pollen of Mezzettia and Platymitra is described for the first time with scanning and transmission electron microscopy. The pollen of all species studied with transmission electron microscopy appeared to possess an inaperturate exine, but apertural areas (‘germination zones’) were observed in the intine. The pollen morphological variation within Miliusa does not correlate with the macromorphological subdivision of the genus. It appeared to be impossible to define distinct pollen types. The former tribe Miliuseae cannot be characterised or subdivided with the help of pollen characters either. All genera fit in the larger miliusoid clade (25 genera). The pollen of the Polyalthia cerasoides group deviates in its finely and densely granular infratectum.

Identifying clades in Asian Annonaceae: monophyletic genera in the polyphyletic Miliuseae

The tribe Miliuseae (Annonaceae) comprises six genera distributed in Asia: Alphonsea, Mezzettia, Miliusa, Orophea, Platymitra, and Phoenicanthus. A phylogenetic study to investigate the putative monophyly of the tribe and the intergeneric relationships is presented here. Nucleotide sequences of the plastid gene rbcL, trnL intron, and trnL-trnF intergenic spacer were analyzed from 114 Annonaceae taxa, including 24 Miliuseae species and two outgroups using maximum parsimony and Bayesian inference. The two data sets (rbcL and the trnL-trnF regions) were analyzed separately and in combination. Miliuseae were found to be polyphyletic due to the position of Mezzettia and are part of a large, predominantly Asian and Central-American clade (miliusoid clade). Although intergeneric relationships were poorly resolved, all genera, except Polyalthia, were monophyletic, supporting previous generic delimitation based on morphology. A group of three Polyalthia species seems the most likely sister group of Miliusa. Several infrageneric groups of Miliusa, Orophea, and Polyalthia are supported by both molecular and morphological data. No morphological synapomorphies have yet been found for the miliusoid clade. Molecular clades within the miliusoid clade, however, can be characterized by size and the shape of the outer petals, number of ovules per carpel, and the size of the fruits.