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Twenty polymorphic microsatellite markers were developed, using Next Generation Sequencing (Illumina), from genomic DNA of Parashorea malaanonan, a species of the Dipterocarpa­ceae which is ecologically and economically important in the Philippines. Thirty adult trees from a natural population were used to assess the success of PCR amplification and the degree of polymorphism. The number of alleles per locus varied from three to 13, and observed and expected heterozygosity varied from 0.200 to 0.808 and from 0.301 to 0.890 respectively. Total exclusion probabilities for the first and second parents over the 20 loci were 0.99932499 and 0.99999723 respectively. The high level of polymorphism at these loci makes it possible to obtain precise estimates of genetic parameters and thus the markers will help in studies on population genetics, conservation gene­tics, and molecular ecology of P. malaanonan.

Parashorea chinensis is an endemic tree species in China and an endangered species of the Dipterocarpaceae family. This study contributes to the understanding of soil fertility management during the relocation and conservation of P. chinensis and the restoration of its natural communities by doing an ecological chemometric investigation of the factors limiting soil nutrients in P. chinensis plantations. To investigate the variation in rhizosphere and non-rhizosphere soil nutrients, microbial biomass, and extracellular enzyme activities, we chose pure plantation stands of 6 ages in the subtropics and calculated stoichiometric ratios. The results show that (1) soil pH is strongly acidic (pH < 4.6) and is less influenced by the stand age, and the soil carbon (C), nitrogen (N), and phosphorus (P) content limit soil microorganisms at all stand ages; (2) the availability of soil N, P, and K elements is an essential factor driving P limitation in the growth of P. chinensis and its soil microbes; (3) stand age has a significant effect on the soil C/N, C/P, N/P, C/K, N/K, and P/K, the stoichiometry of microbial biomass C, N, and P, and the stoichiometry of C, N, and P acquisition enzyme activity. Soil microbial biomass C, N, and P stoichiometry are more sensitive indicators of nutrient limitations than the stoichiometry of enzyme activity and nutrient content; and (4) there was a significant correlation between microbial biomass C, N, and P stoichiometry and soil C/P and N/P, as well as a highly significant (p < 0.01) correlation between the stoichiometry of the enzyme activity and Vector L and Vector A. In conclusion, the plantations of P. chinensis in this study area were established on acidic phosphorus-poor soil, and the ecological stoichiometry of the soil reveals nutrient limitations and its variation with the stand age. P availability plays a key role in the growth of P. chinensis and in improving the rhizosphere microbial community. Therefore, soil effectiveness should be dynamically assessed during the cultivation and relocation conservation of P. chinensis, and a soluble P fertilizer should be supplemental over time in the trees’ root distribution area.

is a rare monodominant species in southwest China known for its production of high-quality timber, is facing decline due to its narrow distribution, human interference and habitat destruction. However, there are no reports on genetic diversity and geographical variation of phenotypic traits of . In this study, phenotypic characters and genetic diversity of 15 germplasms resources from five provenances in southwest China were investigated, and their relationships with geographical and environmental factors was discussed. Our results revealed a rich phenotypic diversity among the germplasms, with variation coefficients ranging from 3.63% to 45.49%. Among the studied germplasms, NP03 from Napo and ML02 from Mengla region exhibited superior phenotypic traits. Notably, NP03 also demonstrated the highest genetic diversity. Genetic differentiation analyses including genetic differentiation coefficient (0.6264) and gene flow (0.3736) illustrated that genetic variation was most prevalent among populations. Furthermore, redundancy analysis showed that temperature related factors (maximum air temperature, annual mean temperature and minimum air temperature) significantly affected phenotypic variation. Similarly, altitude, longitude, latitude, annual mean precipitation and the minimum air temperature significantly impacted the level of genetic diversity. The molecular variation of the natural population of followed a certain geographical pattern. Our finding indicated abundant phenotypic variation among germplasms. However, populations exhibited low levels of genetic diversity alongside high genetic differentiation, potentially contributing to the species' rarity. Based on our results, NP03 and ML02 germplasm could be used as the parents for breeding superior germplasm of . Overall, this study provides valuable insights into germplasm diversity and conservation, genetic improvement, and utilization of .

Phylogenetic relationships within tribe Shoreeae, containing the main elements of tropical forests in Southeast Asia, present a long-standing problem in the systematics of Dipterocarpaceae. Sequencing whole plastomes using next-generation sequencing- (NGS) based genome skimming is increasingly employed for investigating phylogenetic relationships of plants. Here, the usefulness of complete plastid genome sequences in resolving phylogenetic relationships within Shoreeae is evaluated. A pipeline to obtain alignments of whole plastid genome sequences across individuals with different amounts of available data is presented. In total, 48 individuals, representing 37 species and four genera of the ecologically and economically important tribe Shoreeae sensu Ashton, were investigated. Phylogenetic trees were reconstructed using maximum parsimony, maximum likelihood and Bayesian inference. Here, the first fully sequenced plastid genomes for the tribe Shoreeae are presented. Their size, GC content and gene order are comparable with those of other members of Malvales. Phylogenomic analyses demonstrate that whole plastid genomes are useful for inferring phylogenetic relationships among genera and groups of Shorea (Shoreeae) but fail to provide well-supported phylogenetic relationships among some of the most closely related species. Discordance in placement of Parashorea was observed between phylogenetic trees obtained from plastome analyses and those obtained from nuclear single nucleotide polymorphism (SNP) data sets identified in restriction-site associated sequencing (RADseq). Phylogenomic analyses of the entire plastid genomes are useful for inferring phylogenetic relationships at lower taxonomic levels, but are not sufficient for detailed phylogenetic reconstructions of closely related species groups in Shoreeae. Discordance in placement of Parashorea was further investigated for evidence of ancient hybridization.

Background Plant mitochondrial genomes (mitogenomes), essential for cellular energy production and development, are characterized by rapid structural variations and highly diverse non-coding sequences. However, the underlying causes of these variations remain controversial. Dipterocarpaceae, a tropical tree family of ~ 16 genera and 500–700 species, includes many ecologically and economically important taxa. Its largest lineage, Dipterocarpoideae (13 genera, 470–650 species), with a well-resolved evolutionary history, serves as an ideal model for investigating mitogenome evolution. Results Here, we assembled 13 new mitogenomes from the five most species-rich Dipterocarpoideae genera and conducted comprehensive pan-mitogenome analyses. These mitogenomes ranged from 378.3 to 442.8 kb in size and shared 64 conserved core fragments encoding 30 protein-coding genes (PCGs), three unique rRNA genes, and nine unique tRNA genes. Phylogenetic analyses based on organellar and nuclear genomes consistently recovered three major clades: Vatica , Dipterocarpus , and a clade comprising Shorea , Hopea , and Parashorea . The Vatica mitogenomes contained fewer mitochondrial plastid DNAs (MTPTs) and repeats, resulting in a simpler mitogenome structure. In contrast, the other clades contain more MTPTs and repeats, leading to a more complex mitogenome. This pattern suggests that MTPTs and repeats may jointly contribute to increased mitogenome complexity. Moreover, the synonymous substitution rate in coding regions was comparable to that in non-coding regions, while the non-synonymous substitution rate was lower, indicating similar mutation inputs but different selective pressures. Conclusion These findings provide new insights into the structural complexity and evolutionary dynamics of plant mitogenomes.

Dipterocarpoideae, the largest subfamily in the Meranti family (Dipterocarpaceae) are an ecologically dominant group of trees throughout much of wet tropical Asia. Increasing anthropogenic pressures on this economically important tree family make it essential to resolve their complex evolutionary relationships and understand the distribution of genetic diversity throughout the family and distribution range. Dipterocarpaceae have been the focal group in a wide range of studies, owing to their economic value, importance in historical biogeography and key role in the evolution of the Asian tropical forest biome. Despite this, persistent taxonomic and evolutionary questions remain, ranging from questions on the geographic origin, sequence of dispersal and the identification of diagnostic characters to circumscribe proper evolutionary groups. Here we present a comprehensive phylogenomic hypothesis for Dipterocarpoideae, based on the analyses of plastome and nuclear cistron (NRC) data, and provide an in-depth review on the validity of morphological characters underlying the new tribal classification proposed here for the subfamily. Phylogenomic relationships were inferred using maximum likelihood and Bayesian approaches. Estimates of origin and onset of diversification in major clades and lineages were reconstructed using plastome, nuclear and combined datasets. Results of the separate and combined genomic datasets partly corroborate elements of previous classification systems (with improved support at all levels for major clades) but provide strong support for revising the tribal classification of the subfamily into four main clades: Dipterocarpeae (Dipterocarpus), Dryobalanopseae (Dryobalanops), Shoreeae (Hopea, Neobalanocarpus, Parashorea, and all parts of a polyphyletic Shorea) and Vaterieae (including all other presently accepted Dipterocarpoideae genera). Multi-fossil-dated divergence time estimation suggests Vaterieae first originated in the Late Cretaceous, followed by Dipterocarpeae, with subsequent rise of the Dryobalanopseae and Shoreeae in the Eocene. Diversification of all tribes commenced before the Early Miocene. Our results provide strong support for the position of Neobalanocarpus heimii, Parashorea and (sub-)sections of the genera Anisoptera, Hopea, Shorea and Vatica. Hypotheses on the origin of Neobalanocarpus heimii by intergeneric hybridisation between Anthoshorea (maternally inherited) and Hopea (paternally inherited) species were corroborated. Finally, our study provides support for future revisionary changes: (1) the elevation to generic rank of sections in Shorea; and (2) revising the infrageneric classification of Hopea as all (sub-)sections were recovered as not monophyletic.

The goal of this study was to characterise chemical and histochemical properties of five dipterocarp timber wood species (Dipterocarpus kerrii, Hopea plagata, Parashorea malaanoman, Shorea almon, and Shorea contorta) differing in wood service life and utilisation. Wood of H. plagata, the most durable species, contained the lowest concentrations of nitrogen and ligno-protein, the highest C/N ratio and the lowest lignin concentration per dry mass but the highest lignin and extractive concentrations per wood density. FTIR spectroscopic studies of wood and isolated lignins of D. kerrii and H. plagata revealed differences compared to P. malaanoman and Shorea sp., which are species with short service life. Lignins of the Shorea/Parashorea species had a higher G/S ratio than those of H. plagata and D. kerrii. This was also evident from histochemical staining. Principle component analysis of FTIR spectra identified differences in both lignin composition and ligno-protein content as major source of variation.

Given the challenges of slow growth and low survival rates in the early stages of Parashorea chinensis cultivation, identifying sustainable methods to enhance seedling performance is critical for successful reforestation and conservation efforts. This study aimed to address these by investigating the growth-promoting effects of phosphate-solubilizing bacteria (PSB). One-year-old seedlings of P. chinesis were inoculated with PSB strains isolated from the rhizosphere soil of Parashorea chinensis H. Wang plantations Y3, W5, H8, and a mixed strain (Mix), with inoculated seedling as a control (CK). The effects of inoculation on seedling growth, photosynthetic physiology, plant nutrient status, and physiological indicators were comprehensively evaluated. Results showed that PSB inoculation increased seedling height and basal diameter growth of P. chinensis, with an increase of 1.56 cm and 0.53 mm compared to CK, respectively, though the differences were not significant. The Mix treatment significantly improved photosynthesis, with increases in net photosynthetic rate (106.3%), transpiration rate (93.89%), and intercellular CO2 concentration (75.51%) compared to CK. Nutrient levels including total nitrogen, total phosphorus, and total potassium were significantly increased by 15.98%, 25.54%, and 32.12%, respectively, in the Mix treatments compared to CK. Moreover, stress resistance also improved, with higher proline content, soluble sugar, and soluble protein levels. Antioxidant enzyme activities (SOD, CAT, and POD) were increased by 9.83%, 23.66%, and 292.32%, respectively, while MDA content was significantly reduced by 69.01%. The mixed strain treatment also significantly increased acid phosphatase activity by 111.88%. In conclusion, PSB inoculation, particularly with the mixed strain, promoted growth and nutrient uptake photosynthetic efficiency and stress resistance in P. chinensis seedlings, offering a promising biotechnological solution for improving seedling performance.

Parashorea chinensis, an endemic tree species in China’s tropical rainforests, holds ecological and economic importance. Challenges like low resistance, poor quality, and low survival rates hinder its successful cultivation. This study explores the potential of autumn potassium fertilization on Parashorea seedlings from two provenances (Napo and Tianyang). The treatments included no fertilizer (CK-1), a single application of 160 mg K·plant−1 (CK-2), and various potassium levels K1, K2, K3, K4, K5, and K6 (corresponding to 0, 40, 80, 160, 320, and 640 mg·K·plant−1, respectively) combined with nitrogen (200 mg·plant−1) and phosphorus (80 mg·plant−1) fertilization. The findings indicate that autumn potassium application, in conjunction with nitrogen (N) and phosphorus (P) fertilization, significantly enhances seedling height and biomass in both provenances, resulting in an average increase of 101% and 89% under the K4 treatment compared to CK-1 and CK-2, comparatively. Both Napo and Tianyang provenances exhibited distinct responses in photosynthetic rate (2.70 μmol·m−2·s−1 and 1.97 μmol·m−2·s−1, respectively) and stomatal conductance (0.042 mol·m−2·s−1 and 0.029 mol·m−2·s−1, respectively) to the K4 treatment, which proved most effective. The chlorophyll content was significantly higher for Napo provenance with the K3 treatment (74.31%, 58.99%), while for Tianyang, it was higher with the K4 treatment (41.48%, 17.36%), compared to CK-1 and CK-2, respectively. Antioxidant enzymes activity, osmoregulatory capacity, and malondialdehyde content all exhibited variations with potassium application levels, with the K4 treatment offering significant benefits. In Napo provenance, lignin (199.82 mg·g−1) and cellulose (252.38 mg·g−1) peaked at K4, while Tianyang exhibited variation, higher lignin (184.25 mg·g−1) at K3, and cellulose (257.73 mg·g−1) at K4. Nutrient content analysis demonstrates that the K4 treatment enhances nutrient absorption and storage, increasing total N (21.56 mg·kg−1), P (4.69 mg·kg−1), and K (13.49 mg·kg−1) content. A comprehensive analysis reveals that the K4 treatment yields the highest quality scores (1.87, 1.85) and membership values (0.82, 0.68) for both Napo and Tianyang seedlings, with Napo seedlings outperforming their Tianyang provenance. Thus, treatment K4 underscores the effectiveness of autumn potassium applications for robust seedling cultivation and adaptation, offering valuable insights for sustainable cultivation practices.

Xylem vessels and parenchyma cells perform functions such as water transport and nutrient storage in trees. However, they are highly variable in different trees. Therefore, this study aimed to explore the structural change patterns in vessels and parenchyma cells in the sapwood, transition wood, and heartwood of tree species with different degrees of evolution. The structural characteristics of the two types of cells in the sapwood, transitional wood, and heartwood were measured in six species with different levels of evolution, namely, Michelia macclurei Dandy, Cinnamomum camphora (L.) presl, Erythrophleum fordii Oliv, Melaleuca leucadendron L., Parashorea chinensis Wang Hsie and Tectona grandis L.F. The results showed that the more evolved species had larger earlywood vessel lumen diameters, thicker walls, and wider hydraulic diameters, as well as smaller latewood vessel densities, reflecting better water transport effectiveness and higher safety. From the sapwood to the transition wood and heartwood, the earlywood vessel lumen diameter of the more primitive species tended to be stable and then decrease, while that of the more evolved species gradually decreased. The latewood vessel density of the more primitive species tended to be stable and then increase, while that of the more evolved species tended to be stable. Additionally, the starch grains of the more primitive species were mainly distributed in the axial or ray parenchyma cells of the sapwood, while those of the more evolved species were abundantly distributed in the axial and ray parenchyma cells of the sapwood, and the distribution of the starch grains was reduced in the transition wood and heartwood. From the sapwood to the heartwood, the ray parenchyma cell fraction tended to be stable in the more primitive species, and tended to be stable before decreasing in the more evolved species. The pit density in the horizontal wall of the ray parenchyma cells tended to be stable and decrease in the more primitive species, while in the more evolved species it tended to be stable or decrease before stabilizing. Overall, trees’ vessels have gradually undergone the optimal selection of vessels during evolution, and the structural variation in the parenchyma cells contributes to their nutrient storage and transport.