Prunus subgenus Cerasus (cherry) is an economically important group that distributed in temperate regions of the northern hemisphere. However, shared interspecific morphological traits and variability across taxa of Cerasus are among the impediments to taxonomic efforts to correctly delimit taxa. This is further complicated by a lack of genetic information on these taxa, with no focused genomic or phylogenetic studies being done on Cerasus. In this study, we conducted comparative analysis on the complete plastid genomes (plastomes) of 20 Cerasus species to gain a greater understanding of the attributes of the plastome of these taxa while helping resolve their phylogenetic placement in Prunus sensu lato and interspecific relationships within the subgenus. Our results displayed that (1) the plastomes of the 20 Cerasus species studied exhibited a typical quadripartite structure with conversed genome arrangement, structure, and moderate divergence. (2) The average size of complete plastomes for the Cerasus taxa studied was 157,861 bp, ranging from 157,458 to 158,024 bp. A total of 134 genes were annotated, including 86 protein-coding genes, 40 tRNAs, and 8 rRNAs across all species. In simple sequence repeat analysis, we found Cerasus had a comparable number of dispersed and tandem repeats to those identified in other angiosperm taxa, with only P. pseudocerasus found to contain trinucleotide repeats. Nucleotide diversity analysis revealed that the trnG-GCC gene and rpl32-trnL region had the highest Pi value showing potential as phylogenetic markers. (3) Two phylogenetic trees of the plastomes verified the monophyletic relationship of Cerasus and provided a more resolved species-level phylogeny. Our study provides detailed plastome information for exploring the phylogeny of subg. Cerasus taxa. We identified various types of repeats and nucleotide diversity hotspots, which can be a reference for species identification and reconstruction of phylogenetic relationships.

Venerable trees are important natural resources and cultural heritage, offering historical, ecological, social and economic value. However, global warming and anthropogenic activities have threatened their welfare and survival. A comprehensive understanding of their current and future spatial patterns, vis-á-vis environmental conditions, can inform the co-management of sustainable resource use and conservation. We employed the existing spatial occurrence data and environmental variables (bioclimate and elevation) to simulate the optimal habitats for venerable trees in China’s Sichuan Province. We evaluated the current and future climate scenarios of 2100 with double CO2 concentration. The BIOCLIM and QGIS spatial analyses assessed the primary factors of geographical distribution. The results identified 10,720 venerable trees from 123 species, 81 genera and 42 families. Cupressus funebris dominated, with the maximum importance value, followed by Ginkgo biloba, Ficus virens var. sublanceolata, and Phoebe zhennan. The elevation distribution of tree abundance and species richness demonstrated a unimodal pattern, skewing to the low-elevation end, with a concentration in the 600–1500 m low-medium altitude. The majority of trees and excellent habitats were found in eastern Sichuan with a less harsh terrain and climate. The bio3 (isothermality) and bio7 (temperature annual range) factors significantly influenced tree occurrence. Temperature imposed a greater effect on distribution than moisture under the current climate scenario. For the future climate-change scenario, the suitable habitats were predicted to maintain an overall stable pattern, with largely contiguous expansions of better habitats. However, climate warming would shrink the excellent habitats on the plains. The findings can inform strategies and guidelines for venerable-tree conservation in Sichuan. Furthermore, vulnerable areas could be identified. The future range expansion sites could be enlisted to cultivate new trees to replenish the venerable-tree pool. Habitat patches that remain sustainable could provide refugia with the potential for protected-area designation.

Plant functional traits represent adaptive strategies to the environment, linked to biophysical and biogeochemical processes and ecosystem functioning. Compilations of trait data facilitate research in multiple fields from plant ecology through to land-surface modelling. Here we present version 2 of the China Plant Trait Database, which contains information on morphometric, physical, chemical, photosynthetic and hydraulic traits from 1529 unique species in 140 sites spanning a diversity of vegetation types. Version 2 has five improvements compared to the previous version: (1) new data from a 4-km elevation transect on the edge of Tibetan Plateau, including alpine vegetation types not sampled previously; (2) inclusion of traits related to hydraulic processes, including specific sapwood conductance, the area ratio of sapwood to leaf, wood density and turgor loss point; (3) inclusion of information on soil properties to complement the existing data on climate and vegetation (4) assessments and flagging the reliability of individual trait measurements; and (5) inclusion of standardized templates for systematical field sampling and measurements.

Synonymous codon usage bias (SCUB) analysis is an effective method to explore species specificity, evolutionary relationships and mRNA translation, as well as to discover novel genes, which are important for understanding gene function and molecular phylogeny. Cherries (Prunus subg. Cerasus) are flowering plant germplasm resources for edible and ornamental purposes. In this study, we analyzed the codon usage patterns of the 36 chloroplast genomes to provide a scientific basis for elucidating the evolution of subg. Cerasus. The results showed that the average GC content was 0.377, the average GC3 was 0.298, and the average ENC value was 49.69. Neutral-plot analysis, ENC-plot analysis, and PR2-plot analysis all indicated that natural selection was the main factor of codon usage bias in subg. Cerasus, whereas correlation analysis showed that gene expression level and GC1 also affect the codon usage pattern. The codon usage pattern was consistent across 36 species, and 30 high-frequency codons were identified, with preference for A/T endings; there were 23 optimal codons, and only GAU was identified in all individuals; structural differences existed between the clustering tree based on RSCU values and the phylogenetic tree based on CDS, elucidating the importance of locus mutations and no-preference codons in phylogenetic reconstruction. This study describes for the first time the SCUB pattern and characterization of subg. Cerasus chloroplast genomes and provides a new insight to explore the phylogeny of this subgenus.

A new spikemoss species, Selaginella wuyishanensis, is described and illustrated based on materials collected from Fujian Province, East China. The new species can be distinguished from S. lutchuensis Koidzumi and S. albociliata P. S. Wang by its leaves with extremely long cilia (up to 8 mm) and distinctly white margins, ovate ventral sporophylls, and sporophyll-pteryx completely inverted on dorsal sporophylls. In the present work, a molecular phylogeny, taxonomic description, distribution information, line drawing, and photographs of this new species are presented. A morphological comparison is also given to distinguish it from morphologically similar species in Selaginella sect. Tetragonostachyae (Hook. & Grev.) Hieron. & Sadeb.