Diversification in Qinghai-Tibet Plateau: Orchidinae (Orchidaceae) clades exhibiting pre-adaptations play critical role.

We explore the origins of the extraordinary plant diversity in the Qinghai-Tibetan Plateau (QTP) using Orchidinae (Orchidaceae) as a model. Our results indicate that six major clades in Orchidinae exhibited substantial variation in the temporal and spatial sequence of diversification. Our time-calibrated phylogenetic model suggests that the species-richness of Orchidinae arose through a combination of in situ diversification, colonisation, and local recruitment. There are multiple origins of species-richness of Orchidinae in the QTP, and pre-adaptations in clades from North Temperate and alpine regions were crucial for in situ diversification. The geographic analysis identified 29 dispersals from Asia, Africa and Europe into the QTP and 15 dispersals out. Most endemic species of Orchidinae evolved within the past six million years.

The evolution of floral deception in Epipactis veratrifolia (Orchidaceae): from indirect defense to pollination.

BACKGROUND: It is estimated that floral deception has evolved in at least 7500 species of angiosperms, of which two thirds are orchids. Epipactis veratrifolia (Orchidaceae) is a model system of aphid mimicry as aphidophagous hoverflies lay eggs on false brood sites on their flowers. To understand the evolutionary ecology of floral deception, we investigated the pollination biology of E. veratrifolia across 10 populations in the Eastern Himalayas. We reconstructed the phylogeny of Epipactis and mapped the known pollination systems of previously studied species onto the tree. RESULTS: Some inflorescences of E. veratrifolia were so infested with aphids while they were still in bud that the some larvae of hoverflies developed to the third instar while flower buds opened. This indicated that adult female hoverflies were partly rewarded for oviposition. Although flowers failed to secrete nectar, they mimicked both alarm pheromones and aphid coloring of to attract female hoverflies as their exclusive pollinators. Phylogenetic mapping indicate that pollination by aphidophagous hoverflies is likely an ancestral condition in the genus Epipactis. We suggest that the biological interaction of aphid (prey), orchid (primary producer) and hoverfly (predator) may represent an intermediate stage between mutualism and deception in the evolution of pollination-by-deceit in E. veratrifolia. CONCLUSIONS: Our analyses indicate that this intermediate stage may be used as a model system to interpret the origin of oviposition (brood site) mimicry in Epipactis. We propose the hypothesis that some deceptive pollination systems evolved directly from earlier (partly) mutualistic systems that maintained the fidelity of the original pollinator(s) even though rewards (nectar/ brood site) were lost.

Astragalusbashanensis (Leguminosae), a new species from Central China.

A new species Astragalusbashanensis, from western Hubei Province, Central China is described and illustrated. The new species is morphologically similar to Astragalussinicus and A.wulingensis, but differs from both by its spreading pubescent indumentum on stems and petioles, longer petioles, white bracts, whitish or yellow corolla, longer claw of the keel-petal, hairy pods and smaller seeds.

Taxonomic notes on the genus Deutzia (Hydrangeaceae) from Central China.

Based on examination of syntype specimens deposited at P, the lectotype for the name Deutziasetchuenensis Franch. is designated here. By consulting literature and specimen records, the type locality of D.setchuenensisvar.longidentata Rehder, 'Chin-Ting shan' in the protologue is likely a misspelling of 'Chiuting shan' which is now called Jiuding shan located in southern Mao county, Sichuan province. In addition, a new variety, Deutziasetchuenensisvar.macrocarpa Q.L.Gan, Z.Y.Li & S.Z.Xu from western Hubei, Central China, is described and illustrated. It differs from other varieties of D.setchuenensis Franch. by the orange anthers, broader outer filaments, obtuse inner filaments, and larger fruits.

Veronicahongii (Plantaginaceae), a new species from Central China.

A new species Veronicahongii, from western Hubei Province, Central China is described and illustrated. The species is morphologically similar to V.henryi Yamazaki, but mainly differs in the glabrous plant, except pedicels, broadly ovate leaf blades, glandular-pubescent pedicels, obovate calyx lobes, smaller corolla, broadly ovate capsule and much smaller seeds.

A new species of Prunus subgen. Cerasus from Central China.

A new species, Prunuswangii Q.L.Gan, Z.Y.Li & S.Z.Xu from western Hubei, Central China is described and illustrated. It is morphologically similar to P.clarofolia Schneid. and P.pseudocerasus Lindl., but differs in larger height, nearly erect branches, densely and horizontally arranged lenticels, straight lateral veins of leaves, persistent brownish bracts, reflexed and entire calyx lobes, 2-lobed petals with narrowly triangular sinus, earlier flowering and broadly ellipsoid fruits. Furthermore, P.wangii blooms in late February and the colour of flower changes with time, which makes it possible to be a new breeding material for ornamental cherry with early spring blooms.

The complete chloroplast genome sequence of Catalpa fargesii f. duclouxii (Bignoniaceae).

The complete chloroplast genome sequence of Catalpa fargesii f. duclouxii C.A. May was firstly assembled and analyzed in this study. The whole genome of this species was 158164 bp in length, with a typical quadripartite structure. The large single copy (LSC) was 83986 bp, the small single copy (SSC) was 12660 bp, and both of the two inverted repeats (IRs) were 30259 bp, respectively. A total of 134 genes in the chloroplast genome were annotated, including 87 protein-coding genes, 8 ribosomal RNA (rRNA) genes, and 39 transfer RNA (tRNA) genes. The phylogenetic analysis showed that C. fargesii f. duclouxii was highly clustered with C. bungei.

DNA barcoding of invasive plants in China: A resource for identifying invasive plants.

Invasive plants have aroused attention globally for causing ecological damage and having a negative impact on the economy and human health. However, it can be extremely challenging to rapidly and accurately identify invasive plants based on morphology because they are an assemblage of many different families and many plant materials lack sufficient diagnostic characteristics during border inspections. It is therefore urgent to evaluate candidate loci and build a reliable genetic library to prevent invasive plants from entering China. In this study, five common single markers (ITS, ITS2, matK, rbcL and trnH-psbA) were evaluated using 634 species (including 469 invasive plant species in China, 10 new records to China, 16 potentially invasive plant species around the world but not introduced into China yet and 139 plant species native to China) based on three different methods. Our results indicated that ITS2 displayed largest intra- and interspecific divergence (1.72% and 91.46%). Based on NJ tree method, ITS2, ITS, matK, rbcL and trnH-psbA provided 76.84%, 76.5%, 63.21%, 52.86% and 50.68% discrimination rates, respectively. The combination of ITS + matK performed best and provided 91.03% discriminatory power, followed by ITS2 + matK (85.78%). For identifying unknown individuals, ITS + matK had 100% correct identification rate based on our database, followed by ITS/ITS2 (both 93.33%) and ITS2 + matK (91.67%). Thus, we propose ITS/ITS2 + matK as the most suitable barcode for invasive plants in China. This study also demonstrated that DNA barcoding is an efficient tool for identifying invasive species.