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Background The genus Phoebe , belonging to the tribe Perseeae of the Lauraceae, is well known for its important economic value and the need for its conservation. However, the taxonomic delimitation of species remains poorly resolved due to complicated morphological variation in Phoebe , thus hindering conservation efforts and resource utilization. Here we sequenced 18 samples of the genus, reconstructed new plastome phylogenomic trees of Phoebe from East Asia with special emphasis on Phoebe legendrei and its closely related species. We also conducted comparative analyses of both plastomes and morphology between P. legendrei and its closely related species, and examined the protologue and the type collection of P. legendrei , and conducted a taxonomic treatment. Results Our comparative genomic analysis confirmed that plastomes of the genus Phoebe are relatively conservative, but P. legendrei 94 differs from P. legendrei 143 in number of dispersed repeats, IR boundary, and highly variable regions. The newly reconstructed phylogenomic trees are robustly supported, with Phoebe species divided into three major clades. Phoebe crassipedicella is sister to P. kwangsiensis , but the eight samples of P. legendrei formed two separate subclades (represented by P. legendrei 94 differs from P. legendrei 143, respectively). We conducted a morphological study and revealed that the two subclades differed in perianth lobe size, fruiting pedicel length, and the clasping status of the persistent perianth lobes. We examined the protologue and morphology of the type collection of P. legendrei , and determined a new species, i.e., Phoebe panzhihuaensis sp. nov. Conclusions In this study, we resolved the taxonomic delimitation within P. legendrei and its closely related species, and discovered a new species of Phoebe from southwestern China. This work contributes to evaluating species diversity within Phoebe and lays the foundation for the conservation and resource utilization of these species.

Spatial distribution pattern of biological related species present unique opportunities and challenges to explain species coexistence. In this study, we explored the spatial distributions and associations among congeneric species at both the species and genus levels to explain their coexistence through examining the similarities and differences at these two levels. We first used DNA and cluster analysis to confirmed the relative relationship of eight species within a 20 ha subtropical forest in southern China. We compared Diameter at breast height (DBH) classes, aggregation intensities and spatial patterns, associations, and distributions of four closely related species pairs to reveal similarities and differences at the species and genus levels. These comparisons provided insight into the mechanisms of coexistence of these congeners. O-ring statistics were used to measure spatial patterns of species. Omega 0-10, the mean conspecific density within 10 m of a tree, was used as a measure of the intensity of aggregation of a species, and g-function was used to analyze spatial associations. Our results suggested that spatial aggregations were common, but the differences between spatial patterns were reduced at the genus level. Aggregation intensity clearly reduced at the genus level. Negative association frequencies decreased at the genus level, such that independent association was commonplace among all four genera. Relationships between more closely related species appeared to be more competitive at both the species and genus levels. The importance of competition on interactions is most likely influenced by similarity in lifestyle, and the habitat diversity within the species' distribution areas. Relatives with different lifestyles likely produce different distribution patterns through different interaction process. In order to fully understand the mechanisms generating spatial distributions of coexisting siblings, further research is required to determine the spatial patterns and associations at other classification levels.

Background The family Lauraceae is subdivided into six main lineages: Caryodaphnopsideae, Cassytheae, Cryptocaryeae, Hypodaphnideae, Laureae, and Neocinnamomeae. However, phylogenetic relationships among these lineages have been debatable due to incongruence between trees constructed using nuclear ribosomal DNA (nrDNA) sequences and chloroplast (cp) genomes. As with cp DNA, the mitochondrial (mt) DNA of most flowering plants is maternally inherited, so the phylogenetic relationships recovered with mt genomes are expected to be consistent with that from cp genomes, rather than nrDNA sequences. Results The mitogenome of Machilus yunnanensis , with a length of 735,392 bp, has a very different genome size and gene linear order from previously published magnoliid mitogenomes. Phylogenomic reconstructions based on 41 mt genes from 92 Lauraceae mitogenomes resulted in highly supported relationships: sisterhood of the Laureae and a group containing Neocinnamomeae and Caryodaphnopsideae, with Cassytheae being the next sister group, followed by Cryptocaryeae. However, we found significant incongruence among the mitochondrial, chloroplast, and nuclear phylogenies, especially for the species within the Caryodaphnopsideae and Neocinnamomeae lineages. Time-calibrated phylogenetic analyses showed that the split between Caryodaphnopsideae and Neocinnamomeae dated to the later Eocene, around 38.5 Ma, Laureae originated in the Late Cretaceous, around 84.9 Ma, Cassytheae originated in the mid-Cretaceous around 102 Ma, and Cryptocaryeae originated in the Early Cretaceous around 116 Ma. From the Late Cretaceous to the Paleocene, net diversification rates significantly increased across extant clades of major lineages, and both speciation rates and net diversification rates continued steady growth towards the present. Conclusions The topology obtained here for the first time shows that mt genes can be used to support relationships among lineages of Lauraceae. Our results highlight that both Caryodaphnopsideae and Neocinnamomeae lineages are younger than previously thought, likely first diversifying in the Eocene, and species in the other extant lineages of Lauraceae dates in a long-time span from the Early Cretaceous to the Eocene, and the climate of a period of about 90 million years was relatively warm, while the extant species of Lauraceae then continuously diversified with global cooling from the Eocene to the present day.

Lauraceae are an important component of tropical and subtropical forests and have major ecological and economic significance. Owing to lack of clear-cut morphological differences between genera and species, this family is an ideal case for testing the efficacy of DNA barcoding in the identification and discrimination of species and genera. In this study, we evaluated five widely recommended plant DNA barcode loci matK, rbcL, trnH-psbA, ITS2 and the entire ITS region for 409 individuals representing 133 species, 12 genera from China. We tested the ability of DNA barcoding to distinguish species and as an alternative tool for correcting species misidentification. We also used the rbcL+matK+trnH-psbA+ITS loci to investigate the phylogenetic relationships of the species examined. Among the gene regions and their combinations, ITS was the most efficient for identifying species (57.5%) and genera (70%). DNA barcoding also had a positive role for correcting species misidentification (10.8%). Furthermore, based on the results of the phylogenetic analyses, Chinese Lauraceae species formed three supported monophyletic clades, with the Cryptocarya group strongly supported (PP = 1.00, BS = 100%) and the clade including the Persea group, Laureae and Cinnamomum also receiving strong support (PP = 1.00, BS = 98%), whereas the Caryodaphnopsis-Neocinnamomum received only moderate support (PP = 1.00 and BS = 85%). This study indicates that molecular barcoding can assist in screening difficult to identify families like Lauraceae, detecting errors of species identification, as well as helping to reconstruct phylogenetic relationships. DNA barcoding can thus help with large-scale biodiversity inventories and rare species conservation by improving accuracy, as well as reducing time and costs associated with species identification.

In the traditional classification system of the Lauraceae family based on morphology and anatomy, the phylogenetic position of the genus Sassafras has long been controversial. Chloroplast (cp) evolution of Sassafras has not yet been illuminated. In this study, we first sequenced and assembled the complete cp genomes of Sassafras, and conducted the comparative cp genomics, phylogenomics, and divergence time estimation of this ecological and economic important genus. The whole length of cp genomes of the 10 Sassafras ranged from 151,970 bp to 154,011 bp with typical quadripartite structure, conserved gene arrangements and contents. Variations in length of cp were observed in the inverted repeat regions (IRs) and a relatively high usage frequency of codons ending with T/A was detected. Four hypervariable intergenic regions (ccsA-ndhD, trnH-psbA, rps15-ycf1, and petA-psbJ) and 672 cp microsatellites were identified for Sassafras. Phylogenetic analysis based on 106 cp genomes from 30 genera within the Lauraceae family demonstrated that Sassafras constituted a monophyletic clade and grouped a sister branch with the Cinnamomum sect. Camphora within the tribe Cinnamomeae. Divergence time between S. albidum and its East Asian siblings was estimated at the Middle Miocene (16.98 Mya), S. tzumu diverged from S. randaiense at the Pleistocene epoch (3.63 Mya). Combined with fossil evidence, our results further revealed the crucial role of the Bering Land Bridge and glacial refugia in the speciation and differentiation of Sassafras. Overall, our study clarified the evolution pattern of Sassafras cp genomes and elucidated the phylogenetic position and divergence time framework of Sassafras.

Ocotea species present economic importance and biological activities attributed to their essential oils (EOs) and extracts. For this reason, various strategies have been developed for their conservation. The chemical compositions of the essential oils and matK DNA sequences of O. caudata, O. cujumary, and O. caniculata were subjected to comparison with data from O. floribunda, O. veraguensis, and O. whitei, previously reported. The multivariate analysis of chemical composition classified the EOs into two main clusters. Group I was characterized by the presence of α-pinene (9.8–22.5%) and β-pinene (9.7–21.3%) and it includes O. caudata, O. whitei, and O. floribunda. In group II, the oils of O. cujumary and O. caniculata showed high similarity due amounts of β-caryophyllene (22.2% and 18.9%, respectively). The EO of O. veraguensis, rich in p-cymene (19.8%), showed minor similarity among all samples. The oils displayed promising antimicrobial and cytotoxic activities against Escherichia coli (minimum inhibitory concentration (MIC) < 19.5 µg·mL−1) and MCF-7 cells (median inhibitory concentration (IC50) ≅ 65.0 µg·mL−1), respectively. The analysis of matK gene displayed a good correlation with the main class of chemical compounds present in the EOs. However, the matK gene data did not show correlation with specific compounds.

The invasive redbay ambrosia beetle, Xyleborus glabratus, is the primary vector of Raffaelea lauricola, a symbiotic fungus and the etiologic agent of laurel wilt. This lethal disease has caused severe mortality of redbay (Persea borbonia) and swampbay (P. palustris) trees in the southeastern USA, threatens avocado (P. americana) production in Florida, and has potential to impact additional New World species. To date, all North American hosts of X. glabratus and suscepts of laurel wilt are members of the family Lauraceae. This comparative study combined field tests and laboratory bioassays to evaluate attraction and boring preferences of female X. glabratus using freshly-cut bolts from nine species of Lauraceae: avocado (one cultivar of each botanical race), redbay, swampbay, silkbay (Persea humilis), California bay laurel (Umbellularia californica), sassafras (Sassafras albidum), northern spicebush (Lindera benzoin), camphor tree (Cinnamomum camphora), and lancewood (Nectandra coriacea). In addition, volatile collections and gas chromatography-mass spectroscopy (GC-MS) were conducted to quantify terpenoid emissions from test bolts, and electroantennography (EAG) was performed to measure olfactory responses of X. glabratus to terpenoids identified by GC-MS. Significant differences were observed among treatments in both field and laboratory tests. Silkbay and camphor tree attracted the highest numbers of the beetle in the field, and lancewood and spicebush the lowest, whereas boring activity was greatest on silkbay, bay laurel, swampbay, and redbay, and lowest on lancewood, spicebush, and camphor tree. The Guatemalan cultivar of avocado was more attractive than those of the other races, but boring response among the three was equivalent. The results suggest that camphor tree may contain a chemical deterrent to boring, and that different cues are associated with host location and host acceptance. Emissions of α-cubebene, α-copaene, α-humulene, and calamenene were positively correlated with attraction, and EAG analyses confirmed chemoreception of terpenoids by antennal receptors of X. glabratus.

The tropial genus Beilschmiedia , comprising over 250 species worldwide, includes approximately 40 species distributed in the northern tropical forests of Asia. However, the phylogenetic relationships among these Asiatic Beilschmiedia species remain incompletely understood. In this study, we sequenced and assembled complete chloroplast genomes from six Asiatic Beilschmiedia species, including five from China and one from Indonesia. The genomes range in size from 158,275 to 158,620 bp and exhibit a typical quadripartite structure, similar to other basal Lauraceae species. We identified 116 to 122 simple sequence repeats (SSRs) and 19 to 28 dispersed repeats within the genomes. The relative synonymous codon usage (RSCU) of 79 protein-coding genes exhibited minimal variation. Notably, the boundary genes rpl23 and ycf1 displayed varying degrees of expansion and contraction, along with incomplete replication phenomena. Using a sliding window approach, we constructed a coalescent tree with ASTRAL software to analyze the phylogenetic relationships. The resulting main topology was highly consistent with the Maximum Likelihood (ML) and Bayesian inference (BI) analyses, clearly dividing the Asiatic core Beilschmiedia into two distinct groups: Group A and Group B. Group A showed an extremely low nucleotide diversity (π) value of 0.00063, while Group B exhibited 2.79-fold higher diversity. The highly variable regions trnS - trnG and rpl32 - trnL are proposed as molecular markers for distinguishing between Groups A and B. Furthermore, we identified seven additional highly variable regions: ndhF , ndhF - rpl32 , rpl2 , rpl2 - trnH , rpl32 , rps15 - ycf1 , and ycf1 . These regions may serve as potential molecular markers for the Asiatic Beilschmiedia species. These findings provide new insights into the phylogenetic relationships among Asiatic Beilschmiedia species, highlighting the potential of specific molecular markers in future research.

Background Caryodaphnopsis , a group of tropical trees ( ca . 20 spp.) in the family Lauraceae, has an amphi-Pacific disjunct distribution: ten species are distributed in Southeast Asia, while eight species are restricted to tropical rainforests in South America. Previously, phylogenetic analyses using two nuclear markers resolved the relationships among the five species from Latin America. However, the phylogenetic relationships between the species in Asia remain poorly known. Results Here, we first determined the complete mitochondrial genome (mitogenome), plastome, and the nuclear ribosomal cistron (nrDNA) sequences of C. henryi with lengths of 1,168,029 bp, 154,938 bp, and 6495 bp, respectively. We found 2233 repeats and 368 potential SSRs in the mitogenome of C. henryi  and 50 homologous DNA fragments between its mitogenome and plastome. Gene synteny analysis revealed a mass of rearrangements in the mitogenomes of Magnolia biondii , Hernandia nymphaeifolia , and C. henryi  and only six conserved clustered genes among them. In order to reconstruct relationships for the ten  Caryodaphnopsis species in Asia, we created three datasets: one for the mitogenome (coding genes and ten intergenic regions), another for the plastome (whole genome), and the other for the nuclear ribosomal cistron. All of the 22 Caryodaphnopsis individuals were divided into four, five, and six different clades in the phylogenies based on mitogenome, plastome, and nrDNA datasets, respectively. Conclusions The study showed phylogenetic conflicts within and between nuclear and organellar genome data of Caryodaphnopsis species. The sympatric  Caryodaphnopsis species in Hekou and Malipo SW China may be related to the incomplete lineage sorting, chloroplast capture, and/or hybridization, which mixed the species as a complex in their evolutionary history.

Globally, plant-derived natural products such as essential oils serve as primary sources of functional substances for spices, pharmaceuticals, and other applications. With the increasing focus on health and well-being, alongside ongoing public health challenges, there is a critical need to enhance the deep utilization of natural plant products. Lauraceae family essential oils, characterized by their aromatic, volatile properties and notable biological activities (e.g., antibacterial, antioxidant, insect-repellent), hold significant application value across fragrance, cosmetics, chemical industries, biological pesticides, and medicine. Integrating multi-disciplinary data from biology, genomics, metabolomics, and related fields can accelerate comprehensive insights into the biosynthesis mechanisms and functional roles of these essential oils, thereby promoting the development and application of Lauraceae natural products. This review systematically summarizes the accumulation patterns and compositional characteristics of essential oils across diverse genera of Lauraceae. It further explores the evolutionary dynamics of terpene synthase (TPS) gene families and key genes involved in terpenoid biosynthesis pathways, leveraging genomic datasets from Lauraceae species. Finally, the review highlights future research trends for optimizing Lauraceae essential oil resource utilization and advancing molecular breeding of high-oil-content species within the family.