Nianhe Xia

Testing DNA barcodes in closely related species of Curcuma (Zingiberaceae) from Myanmar and China

The genus Curcuma L. is commonly used as spices, medicines, dyes and ornamentals. Owing to its economic significance and lack of clear‐cut morphological differences between species, this genus is an ideal case for developing DNA barcodes. In this study, four chloroplast DNA regions (matK, rbcL, trnH‐psbA and trnL‐F) and one nuclear region (ITS2) were generated for 44 Curcuma species and five species from closely related genera, represented by 96 samples. PCR amplification success rate, intra‐ and inter‐specific genetic distance variation and the correct identification percentage were taken into account to assess candidate barcode regions. PCR and sequence success rate were high in matK (89.7%), rbcL (100%), trnH‐psbA (100%), trnL‐F (95.7%) and ITS2 (82.6%) regions. The results further showed that four candidate chloroplast barcoding regions (matK, rbcL, trnH‐psbA and trnL‐F) yield no barcode gaps, indicating that the genus Curcuma represents a challenging group for DNA barcoding. The ITS2 region presented large interspecific variation and provided the highest correct identification rates (46.7%) based on BLASTClust method among the five regions. However, the ITS2 only provided 7.9% based on NJ tree method. An increase in discriminatory power needs the development of more variable markers.

Multi-gene region phylogenetic analyses suggest reticulate evolution and a clade of Australian origin among paleotropical woody bamboos (Poaceae: Bambusoideae: Bambuseae)

The paleotropical woody bamboo subtribe Bambusinae has not been satisfactorily circumscribed and remains a major taxonomic problem. Genera such as Holttumochloa, Mullerochloa and Temburongia have not been confidently assigned to this subtribe. The phylogenetic relationships among genera hitherto placed in or near the Bambusinae, together with the related subtribes Racemobambosinae and Melocanninae, were investigated using three chloroplast DNA markers (rps16-trnQ, trnC-rpoB and trnD-T intergenic spacers) and a nuclear DNA marker (granule-bound starch synthase I, GBSSI) for a sample of 51 ingroup species and 2 outgroup species. Phylogenetic analyses revealed four distinct lineages among the members of the currently recognized Bambusinae: (1) the Bambusa-Dendrocalamus-Gigantochloa (BDG) complex, (2) the Holttumochloa-Kinabaluchloa clade, (3) the Dinochloa-Mullerochloa-Neololeba-Sphaerobambos (DMNS) clade and (4) Temburongia simplex. The BDG complex, which comprises the core of the Bambusinae, appears to have a complex evolutionary history as indicated by incongruence between the cpDNA and the nuclear gene topologies. Introgressive hybridization and incomplete lineage sorting are possible underlying causes for this complexity. The distinction of the climbing-scrambling bamboo lineages from the core Bambusinae and Racemobambosinae suggests directions for investigating the possible existence of further subtribes with increased taxon and geographical sampling. Possible biogeographic scenarios associated with the Holttumochloa-Kinabaluchloa clade and the DMNS clade are discussed.

Embryology of Handeliodendron bodinieri (Sapindaceae) and its systematic value: development of male and female gametophytes

Embryological characters of Handeliodendronbodinieri (Sapindaceae) are reported for the first time. Anthers are tetrasporangiate. Cytokinesis in microsporocyte meiosis is of the simultaneous type and the microspore tetrads are tetrahedral. The tapetum is secretory and parietal. Mature pollen is bicellular. The ovary is trilocular. There are two ovules in each locule. The placenta is axile. The ovule is crassinucellate, bitegmic and hemitropous, without hypostase when mature. The development of the embryo sac is of the Polygonum type. The systematic significance of the embryological characters of Handeliodendronbodinieri is discussed.

Taxonomic studies on Zingiber (Zingiberaceae) in China I: Zingiber kerrii and the synonymy of Z. menghaiense and Z. stipitatum

A general introduction to Zingiber is provided, along with an outline of the materials and methods used in this paper and which are to be used in our subsequent taxonomic studies on Zingiber in China. Based on an investigation of the protologues, and on comparisons of both the type specimens and living materials collected from the type localities and their immediate vicinities, Zingiber stipitatum S.Q.Tong and Z. menghaiense S.Q.Tong are here reduced to synonymy under Z. kerrii Craib. A previous lectotypification of Zingiber kerrii is discussed and amended. The existence of mixed collections among the isotypes of Zingiber stipitatum is highlighted and a proposal to exclude the vegetative parts belonging to Z. neotruncatum from the type material is made. A description and a colour plate of Zingiber kerrii based on a collection from China are provided.

Wuacanthus (Acanthaceae), a new Chinese endemic genus segregated from Justicia (Acanthaceae)

A new genus, Wuacanthus Y.F. Deng, N.H. Xia & H. Peng (Acanthaceae), is described from the Hengduan Mountains, China. Wuacanthus is based on Wuacanthus microdontus (W.W.Sm.) Y.F. Deng, N.H. Xia & H. Peng, originally published in Justicia and then moved to Mananthes. The new genus is characterized by its shrub habit, strongly 2-lipped corolla, the 2-lobed upper lip, 3-lobed lower lip, 2 stamens, bithecous anthers, parallel thecae with two spurs at the base, 2 ovules in each locule, and the 4-seeded capsule. Phylogenetic analyses show that the new genus belongs to the Pseuderanthemum lineage in tribe Justicieae. Wuacanthus is closely related to Pseuderanthemum but differs from the latter by its shorter corolla tube and two minute spurs at the base of each anther-theca. W. microdontus is assessed with the status EN B2ab (iii) based on the IUCN Red List Categories and Criteria.

Saussurea wenchengiae (Asteraceae), a New Species from Qinghai, China

Saussurea wenchengiae B.Q. Xu, G. Hao & N.H. Xia, a new species from Qinghai, China, of Saussurea subg. Amphilaena sect. Pseudoamphilaena, is described and illustrated. It is similar to S. polycolea, but differs in its shorter stature, narrowly elliptic middle and upper stem leaf blade with a denticulate margin, and a cylindrical or narrowly campanulate involucre. A color plate, line drawings, a distribution map of S. wenchengiae, and SEM microphotographs of the leaf surfaces of S. wenchengiae and S. polycolea are provided.

A new bamboo species of Dendrocalamus Nees (Poaceae: Bambusoideae) from Yen Bai and Phu Tho provinces, Vietnam

ABSTRACT A new species of the genus Dendrocalamus Nees (Poaceae: Bambusoideae), D. concaviapiculus N.H.Xia et V.T.Nguyen, sp. nov., is described and illustrated from Yen Bai and Phu Tho provinces, Vietnam. It differs from other related Dendrocalamus species by its 5-veined palea between keels and without any vein, its apex and ligule of culm sheath concave, its culm sheath blade short, and its flexuose basal culm internodes.

Floral organogenesis of Delavaya toxocarpa (Sapindaceae; Sapindales).

Abstract  The floral organogenesis and development of Delavaya toxocarpa Franch. (Sapindaceae) were studied under scanning electron microscope and light microscope to determine its systematic position within Sapindaceae. Flowers arise in terminal thyrses. The sepal primordia initiate in a spiral (2/5) sequence, which are not synchronous. The five petal primordia initiate almost synchronously and alternate with sepal primordia. Eight stamens initiate almost simultaneously and their differentiation precedes that of the petals. The last formed petal and one stamen initiate from a common primordium. Mature stamens curve inwards and cover the ovary in bud. The gynoecium begins as a hemispheric primordium on which two carpellary lobes arise simultaneously. Later in development a single gynocium is formed with two locules and two ovules per locule. Floral morphology suggests a closer affinity with Sapindaceae, although certain features of floral ontogenesis are similar to those observed in certain members of the former Hippocastanaceae, such as Handeliodendron.

Chimonocalamus baviensis, A New Combination in Vietnamese Bambusoideae (Poaceae)

Arundinaria baviensis Balansa was found to have short-necked pachymorph rhizomes and culms with nodal rings of root thorns, especially dense at lower nodes. This is in accordance with the characteristics of Chimonocalamus, and therefore a new combination, Chimonocalamus baviensis (Balansa) N.H. Xia, V.L. Le & Y.F. Deng, is proposed.

Annamocalamus H. N. Nguyen, N.-H. Xia & V. T. Tran, a New Genus of Bamboo (Poaceae) from Vietnam

Abstract Tien Tran, V., H. Nghia Nguyen & N.-H. Xia (2013). Annamocalamus H. N. Nguyen, N. H. Xia & V. T. Tran, a new genus of bamboo (Poaceae) from Vietnam. Candollea 68: 159–165. In English, English and French abstracts. Annamocalamus H. N. Nguyen, N.-H. Xia & V. T. Tran (Poaceae-Bambusoideae), a new genus from Vietnam, is described and illustrated. It is based on the species Annamocalamus kontumensis H. N. Nguyen, N.-H. Xia & V. T. Tran. The new genus shares some morphological characters with Melocanna Trin. and Stapletonia Dash & al. but can be recognized by its shorter rhizome and the occurrence of pseudospikelets.