Heterospecific pollen avoidance strategy prevails in the generalized plant-pollinator network on Yongxing Island.

Heterospecific pollen (HP) deposition varies widely among species in communities, which has been explicated by two adaptation strategies: HP avoidance and HP tolerance. Studies of the plant-pollinator network have uncovered that oceanic island communities are highly generalized and strongly connected. It remains unclear, however, which strategy prevails in such communities. We examined stigma pollen deposition on 29 plant species, and assessed patterns of HP load size and diversity in the Yongxing Island community. We assessed the effects of phenotypic specialization and species-level network structural properties of plant species on pollen deposition among species. The hypothesis of three accrual patterns of HP within species was tested by illustrating the relationship between conspecific pollen (CP) and HP receipt. Extensive variation occurred among species in HP receipt, while 75.9% of species received less than 10% HP and one species received more than 40% HP throughout the community. Flower size strongly drives the variation of HP receipt, while network structural properties had no effect on the pollen receipt. Nineteen species showed no relationship between the number of HP and CP loads, and they received smaller HP load sizes and lower HP proportions. Most plant species evolved HP avoidance strategy, and HP receipt was an occasional event for most plant species in the generalized community. HP and CP receipts are independent of each other in plant species with the HP avoidance mechanism. Our results highlight that plants in the generalized pollination system may preferentially select to minimize the HP load on stigmas.

The complete plastid genome sequence of Lysidice brevicalyx (Fabaceae: Detarioideae), an arbor species endemic to China.

The plastid genome of Lysidice brevicalyx was successfully assembled using Illumina sequencing reads for the first time. The complete plastid genome of L. brevicalyx is a circular structure of 159,084 bp with a GC content of 36.4%. It comprises a large single-copy (LSC) region of 87,783 bp, a small single-copy (SSC) region of 19,557 bp, and two inverted repeat regions (IRA and IRB) of 25,872 bp, each. The plastome of L. brevicalyx contains a total of 128 genes, including 83 protein-coding genes, 37 tRNAs, and 8 rRNAs. The phylogenetic analysis strongly supports the monophyly of Lysidice. This study provides the first complete plastid genome sequence of L. brevicalyx and contributes to our understanding of the molecular characteristics and evolutionary relationships of this plant species.

Plastid phylogenomics and biogeography of the medicinal plant lineage Hyoscyameae (Solanaceae).

The cosmopolitan family Solanaceae, which originated and first diversified in South America, is economically important. The tribe Hyoscyameae is one of the three clades in Solanaceae that occurs outside of the New World; Hyoscyameae genera are distributed mainly in Europe and Asia, and have centers of species diversity in the Qinghai-Tibet Plateau and adjacent regions. Although many phylogenetic studies have focused on Solanaceae, the phylogenetic relationships within the tribe Hyoscyameae and its biogeographic history remain obscure. In this study, we reconstructed the phylogeny of Hyoscyameae based on whole chloroplast genome data, and estimated lineage divergence times according to the newly reported fruit fossil from the Eocene Patagonia, Physalis infinemundi, the earliest known fossil of Solanaceae. We reconstructed a robust phylogeny of Hyoscyameae that reveals the berry fruit-type Atropa is sister to the six capsule-bearing genera (Hyoscyameae sensu stricto), Atropanthe is sister to the clade (Scopolia, Physochlaina, Przewalskia), and together they are sister to the robustly supported Anisodus-Hyoscyamus clade. The stem age of Hyoscyameae was inferred to be in the Eocene (47.11 Ma, 95% HPD: 36.75-57.86 Ma), and the crown ages of Hyoscyameae sensu stricto were estimated as the early Miocene (22.52 Ma, 95% HPD: 15.19-30.53 Ma), which shows a close correlation with the rapid uplift of the Qinghai-Tibet Plateau at the Paleogene/Neogene boundary. Our results provide insights into the phylogenetic relationships and the history of the biogeographic diversification of the tribe Hyoscyameae, as well as plant diversification on the Qinghai-Tibet Plateau.

Re-establishment of the genus Ania Lindl. (Orchidaceae).

Ania Lindl. is a small genus of the tribe Collabieae subtribe Collabiinae (Orchidaceae). For the last 150 years, it has generally been treated as a synonym of Tainia Blume. In this study, we critically re-examined morphological characters that have been used to distinguish Ania from Tainia, and assessed the phylogeny of Tainia using morphological and palynological characters. Sequences of the nuclear ribosomal ITS, chloroplast trnL intron and combined DNA data sets were analysed to clarify the delimitation and the phylogeny of these groups. The morphological and palynological survey revealed a number of useful diagnostic characters which permit a clear definition of Ania, after the exclusion of a single taxonomically questionable species. Results confirmed that Ania is distinct from Tainia. Phylogenetic reconstructions based on molecular data provided the greatest resolution and produced a morphologically well differentiated clade of Ania. In addition to morphological and suggested palynological characters, the phylogenies were also supported by karyological evidence. Our results support the independent generic status of Ania. The genus name Ania is revived and re-established.

A cytological study on Kelloggia (Rubiaceae), an intercontinental disjunct genus between eastern Asia and western North America.

A cytological study was carried out for the first time on four populations of the only two species of Kelloggia (Rubiaceae), which occur disjunctly in eastern Asia (K. chinensis Franch.) and western North America (K. galioides Torr.). The consistent mitotic prophase chromosome condensation pattern and interphase nuclei type were determined for both species. The chromosome base number of the genus is suggested to be x = 11. The karyotype of 2n = 22 = 2x = 16m + 6sm was examined for both species. The karyotypical asymmetry of 1A and 2A was found in K. chinensis and K. galioides, respectively. According to the predominant evolutionary direction of karyotype asymmetry in angiosperms, K. galioides (2A) seems slightly more evolved than K. chinensis (1A). Our finding is consistent with the hypothesis of the Old World origin of Kelloggia based on molecular study.