Salicaceae is a family of temperate woody plants in the Northern Hemisphere that are highly valued, both ecologically and economically. China contains the highest species diversity of these plants. Despite their widespread human use, how the species diversity patterns of Salicaceae plants formed remains mostly unknown, and these may be significantly affected by global climate warming. Using past, present, and future environmental data and 2673 georeferenced specimen records, we first simulated the dynamic changes in suitable habitats and population structures of Salicaceae. Based on this, we next identified those areas at high risk of habitat loss and population declines under different climate change scenarios/years. We also mapped the patterns of species diversity by constructing niche models for 215 Salicaceae species, and assessed the driving factors affecting their current diversity patterns. The niche models showed Salicaceae family underwent extensive population expansion during the Last Inter Glacial period but retreated to lower latitudes during and since the period of the Last Glacial Maximum. Looking ahead, as climate warming intensifies, suitable habitats will shift to higher latitudes and those at lower latitudes will become less abundant. Finally, the western regions of China harbor the greatest endemism and species diversity of Salicaceae, which are significantly influenced by annual precipitation and mean temperature, ultraviolet-B (UV-B) radiation, and the anomaly of precipitation seasonality. From these results, we infer water–energy dynamic equilibrium and historical climate change are both the main factors likely regulating contemporary species diversity and distribution patterns. Nevertheless, this work also suggests that other, possibly interacting, factors (ambient energy, disturbance history, soil condition) influence the large-scale pattern of Salicaceae species diversity in China, making a simple explanation for it unlikely. Because Southwest China likely served as a refuge for Salicaceae species during the Last Glacial Maximum, it is a current hotspot for endemisms. Under predicted climate change, Salicaceae plants may well face higher risks to their persistence in southwest China, so efforts to support their in-situ conservation there are urgently needed.

Gene duplication is increasingly recognized as an important mechanism for the origination of new genes, as revealed by comparative genomic analysis. However, how new duplicate genes contribute to phenotypic evolution remains largely unknown, especially in plants. Here, we identified the new gene EXOV, derived from a partial gene duplication of its parental gene EXOVL in Arabidopsis thaliana. EXOV is a species-specific gene that originated within the last 3.5 million years and shows strong signals of positive selection. Unexpectedly, RNA-sequencing analyses revealed that, despite its young age, EXOV has acquired many novel direct and indirect interactions in which the parental gene does not engage. This observation is consistent with the high, selection-driven substitution rate of its encoded protein, in contrast to the slowly evolving EXOVL, suggesting an important role for EXOV in phenotypic evolution. We observed significant differentiation of morphological changes for all phenotypes assessed in genome-edited and T-DNA insertional single mutants and in double T-DNA insertion mutants in EXOV and EXOVL. We discovered a substantial divergence of phenotypic effects by principal component analyses, suggesting neofunctionalization of the new gene. These results reveal a young gene that plays critical roles in biological processes that underlie morphological evolution in A. thaliana.

Primula dongchuanensis Z.K.Wu & Yuan Huang, a new species of Primulaceae from Dongchuan of northern Yunnan, China, is described and illustrated. Both morphological and molecular evidence support P. dongchuanensis as a member of the sect. Proliferae. It is similar to P. aurantiaca W.W.Smith & Forrest, but is distinguished by having unique raceme inflorescences. Its distribution, phenology and conservation status are also provided.

The genus Salix is a common component of the Northern Hemisphere dendroflora with important ecological and economic value. However, taxonomy and systematics of Salix is extremely difficult and relationships between main lineages, especially deep phylogenies, remain largely unresolved. In this study, we used genome-skimming, plastome assembly, and single-copy orthologs (SCOs) from 66 Salix accessions, along with publicly available plastome and sequence read archive (SRA) datasets to obtain a robust backbone phylogeny of Salix, clarify relationships between its main lineages, and gain a more precise understanding of the origin and diversification of this species-rich genus. The plastome and SCO datasets resolved Salix into two robust clades, with plastome-based phylogenies lacking inner resolution and SCO offering fully resolved phylogenies. Our results support the classification of Salix into five subgenera: Salix, Urbaniana, Triandrae, Longifoliae and Vetrix. We observed a significant acceleration in the diversification rate within the Chamaetia-Vetrix clade, while Salix exhibited increased rates of diversification spanning from the early Oligocene to the late Miocene. These changes coincided with contemporaneous tectonic and climate change events. Our results provide a foundation for future systematic and evolutionary studies of Salix. Additionally, we showed that genome skimming data is an efficient, rapid, and reliable approach for obtaining extensive genomic data for phylogenomic studies, enabling the comprehensive elucidation of Salix relationships.

Salix cardiophylla was a member of the genus of Salix in family Salicaceae with unique morphological traits, and once recognized as a separate genus, Toisusu Kimura. Here, we sequenced and assembled the complete mitochondrial genome of S. cardiophylla, which was 735,173 bp in length, including 56 genes, 28 protein-coding genes, 3 rRNA genes, 25 tRNA genes, and one large inverted repeat regions with length of 13,603 bp. Phylogenetic analysis based on 26 mitochondrial CDS confirmed that S. cardiophylla is a member of Salix, and support its merge into Salix in aspect of our new insights on mitogenome phylogenomics.

Primula bulleyana is a popular ornamental species, with high commercial values. Here, we reported the first chloroplast genome of P. bulleyana. The complete chloroplast genome is 150978 bp, containing a large single-copy (LSC) region of 82873 bp, a small single-copy (SSC) region of 17,741 bp, and a pair of inverted repeats (IRs) regions of 25,182 bp. In total, there are 142 genes, 92 protein-coding genes, 8 rRNA genes, and 38 tRNA genes are annotated in the whole cp genome, including 119 unique genes, 82 unique CDSs, 29 unique tRNAs, and 4 unique rRNAs. The overall GC content of the cp genome is 37.1%. The phylogenetic tree shows that close relationships among P. bulleyana and Primula stenodonta.