The findings of this study reveal that a species（Petrocosmea condorensis Pellegr.）， described in Petrocosmea one hundred years ago， in fact represents an independent genus in Gesneriaceae. This species is characterized by a flat-faced corolla， suborbicular leaf blades， linear filaments， and conical-ovoid capsules dehiscing into two valves， exhibiting a series of unique morphological characters. Molecular phylogenetic analyses demonstrated that this species belonged to the subtribe Loxocarpinae（Tribe Trichosporeae） within the subfamily Didymocarpoideae of Gesneriaceae and is sister to a clade comprising several other genera. Based on morphological and molecular phylogenetic evidence， we here elevated this species to a new genus， Zhenyuenes， with the establishment of a new combination.

To establish an efficient polyploid induction protocol for Primula filchnerae， seeds and shoot apices were treated with colchicine using the seed immersion method and the cotton ball dropping method. The effects of different colchicine concentrations and treatment durations on germination rate， mortality rate and tetraploid induction rate were compared. Flow cytometry and root-tip chromosome counting were used for ploidy detection and verification. The results showed that colchicine treatment generally suppressed seed germination and increased seedling mortality rate， but it significantly increased the tetraploid induction rate at the optimal concentration. For seed treatment， the highest germination rate（77.67±3.51）% occurred under 0.02 g⋅L^-1 colchicine treatment for 24 h， while the lowest mortality rate（2.16±0.93）% and the highest tetraploid induction rate （30.12±4.02）% occurred under 0.05 g⋅L^-1 colchicine treatment for 24 h. For the shoot apex treatment， 0.05 g⋅L^-1 colchicine treatment had the highest tetraploid induction rate of （40.00±10.00）%. Flow cytometry analysis revealed that the G₀/G₁ peak of tetraploid plants was significantly shifted from that of diploids， and chromosome counting confirmed that the diploid chromosome number was 2n=2x=24 and the tetraploid chromosome number was 2n=4x=48. Morphological and cytological comparative analysis indicated that the leaf and flower-related traits such as growth potential and ornamental value of tetraploid plants were significantly superior to that of diploid plants. In addition， tetraploids had an increased stomatal size and a decreased stomatal density compared to diploids， which is consistent with typical cytological features of polyploids. In summary， this study established an efficient colchicine-induced polyploidization and ploidy identification protocol for P. filchnerae， and provides technical support for polyploid breeding and germplasm innovation in the species.

Photoperiod serves as the key environmental cue governing seasonal growth and growth cessation in forest trees. Within the perception and transduction of photoperiodic signals， LUX ARRHYTHMO（LUX）， a core component of the circadian clock Evening Complex（EC）， plays a pivotal role. In the present study， a total of 47 BpLUX homologous genes were identified through genome-wide analysis in the reference genome of Betula platyphylla. Bioinformatic analyses revealed that BpLUX1， BpLUX5， and BpLUX18 harbor typical Evening Element（EE） cis-acting elements. All three genes possessed characteristic MYB conserved domains， while BpLUX1 and BpLUX5 additionally exhibited typical circadian rhythmic expression patterns. Using CRISPR/Cas9-mediated genome editing， loss-of-function mutants for BpLUX1（bplux1） were successfully generated， whereas targeted knockout of BpLUX5 proved unsuccessful. Phenotypic characterization demonstrated that under short-day（SD） conditions， wild-type birch ceased growth almost entirely by day 19 in response to shortened photoperiods， whereas bplux1 mutants remained actively growing. Furthermore， while no significant difference in plant height was observed in wild-type plants， bplux1 mutants displayed significantly increased height， exhibiting a delayed growth cessation phenotype. These findings indicate that BpLUX1 is a key gene mediating short-day responses and growth cessation in birch. Transcriptome analysis further revealed that under SD conditions， eleven differentially expressed genes（DEGs） were down-regulated in bplux1 mutants， including BpRCAR1 （Regulatory Component of ABA Receptor 1） involved in ABA （abscisic acid） signaling， whereas seven DEGs were up-regulated， including BpRGL1（RGA-Like1） associated with GA （gibberellin） signaling. Notably， potential binding sites between BpLUX1 and key DEGs in ABA and GA signaling pathways were identified， suggesting that BpLUX1 may influence growth cessation through modulation of phytohormone signaling. Collectively， this study provides a theoretical basis for understanding the role of BpLUX1 in photoperiod-regulated growth cessation in birch.

In the present study， the glutathione S-transferase gene（MiGST） from Meconopsisintegrifolia was cloned， and the biological function through Arabidopsisthaliana transformation was characterized. This study could provide the theoretical basis for flavonoid development and utilization in different tissues of M. integrifolia. The MiGST gene cloned was analyzed by using bioinformatics methods. Then， the tissue expression patterns were examined by real-time fluorescence quantitative polymerase chain reaction（RT-qPCR）. Subsequently， A. thaliana was transformed using the floral dip method， and the total flavonoid content in T₁ transgenic lines was determined by the Al（NO₃）₃ colorimetric assay. The results showed that the coding sequence（CDS） of MiGST was 702 bp in length， which encoded a 234-amino acid protein. The protein molecular weight was 25 861.91 Da with a theoretical isoelectric point of 5.84. Phylogenetic analysis showed that MiGST protein was the most closely related with GST protein from Papaver somniferum. Meanwhile， MiGST gene exhibited the tissue-specific expression， with the highest level in flowers and the lowest in stems. Besides， the total flavonoid contentwithin A. thaliana overexpressing MiGST gene was a 1.27-fold of that of the wild-type one. In conclusion， this study confirmed that overexpression of MiGST gene significantly enhanced the total flavonoid content in transgenic A. thaliana， suggesting that MiGST gene played an important role in the transmembrane transport and accumulation of flavonoids in M. integrifolia.

NAC（NAM， ATAF， and CUC） transcription factors are plant-specific transcriptional regulators that play crucial roles in plant growth， development， and responses to abiotic stresses. To systematically characterize the molecular evolutionary features of theNAC gene family in Catalpa bungei and elucidate its regulatory mechanisms under cold stress， NAC gene family members were comprehensively identified based on the whole-genome sequence of C. bungei. Comprehensive analyses were performed， including physicochemical properties， phylogenetic topology， gene structure conservation， cis-acting elements in promoter regions， cold-responsive expression patterns， and weighted gene co-expression network analysis（WGCNA）. The results demonstrated that a total of 65 CbuNAC genes were identified in the C. bungei genome and classified into four highly conserved subfamilies based on phylogenetic analysis. Chromosomal mapping revealed that these genes were unevenly distributed across 16 chromosomes， displaying a distinct clustered distribution pattern. Gene structure and conserved motif analyses indicated that members within the same subfamily exhibited highly similar intron-exon organization and conserved motif composition，which not only supported the reliability of the phylogenetic classification but also implied potential functional redundancy and evolutionary divergence within subfamilies. Collinearity analysis indicated that segmental duplication， rather than tandem duplication， was the predominant driving force for the expansion and evolutionary divergence of the CbuNAC gene family. Time-series transcriptome analysis under cold stress revealed that CbuNAC15， CbuNAC30， and CbuNAC36 were significantly upregulated， exhibiting strong and temporally dynamic responses to low-temperature stress. Furthermore， WGCNA revealed that the three core genes not only coordinately regulated the classical ICE1-CBF cold-signaling pathway but were also closely associated with downstream genes involved in osmotic adjustment and hormone metabolism. In summary， this study systematically characterized the genomic features of the NAC gene family in C. bungei and identified three key candidate genes associated with cold-tolerance， thereby providing valuable theoretical insights and candidate targets for elucidating abiotic stress adaptation mechanisms in woody plants and advancing marker-assisted breeding.

The stem， as one of the main storage organs of trees， plays a crucial role in wood production； enhancing its storage capacity（sink strength） is of great significance for increasing wood yield. WOX4 belongs to the WUSCHEL-related homeobox（WOX） transcription factor family and functions in maintaining vascular cambium stem cell activity and promoting cell proliferation， thereby regulating secondary growth in stems and roots. It is highly expressed during xylem development in stems and roots. In this study， RT-qPCR was used to analyze the relative expression levels of the PxWOX4a gene in different tissues. In addition， transgenic plants harboring the pPxWOX4a：：GUS construct were subjected to GUS staining to further analyze the expression pattern of the PxWOX4a promoter. The results showed that WOX4a was highly expressed in the stems of Populus×xiaohei. The upstream 1 742 bp promoter region was cloned， and cis-acting element analysis revealed that it contained multiple light-responsive elements， including G-box， I-box， and Box4. A reporter vector（pBI121-pPxWOX4a：：GUS） was generated and transformed into P. alba×P. glandulosa ‘84K’. Molecular analysis confirmed stable integration of the transgene into the genome. RT-qPCR and GUS histochemical staining demonstrated that the PxWOX4a promoter drove strong expression of the GUS gene in stems. These results indicated that the PxWOX4a promoter cloned from Populus × xiaohei exhibited stem-specific and high activity. It therefore provides a useful tool for stem-targeted genetic engineering to regulate wood formation and improve biomass yield in poplar and other forest trees.

This study aimed to optimize the preparation methods of protoplasts from cotyledons and root callus of Andrographis paniculata， and to investigate the key factors affecting their transient transformation， thereby laying a technical foundation for subsequent genetic transformation and gene function research in A. paniculata. The effects of different mannitol concentrations， enzyme concentrations， and enzymatic hydrolysis time on protoplast yield and viability were studied using the enzymatic hydrolysis method. The PEG-mediated transformation method was employed to examine the influence of factors such as PEG concentration and transformation time on transient transformation efficiency， and a transient transformation system for A. paniculata root callus protoplasts was established. The optimal conditions for protoplast preparation from A. paniculata cotyledons were as follows： 0.2 g cotyledons were enzymatically hydrolyzed in a solution containing 4.0% cellulase R-10， 1.5% macerozyme R-10， and 0.6 mol⋅L^-1 mannitol at 26 ℃ and 55 r⋅min^-1 in darkness for 4 h. Under these conditions， the protoplast yield reached 3.32×10⁵ cells⋅mL^-1， with a viability of 90.73%. For root callus protoplasts， the optimal conditions were： 0.4 g 15‑day‑old callus was enzymatically hydrolyzed in a solution containing 4.0% cellulase R-10， 1.0% macerozyme R-10， and 0.8 mol⋅L^-1 mannitol under the same conditions for 9 h， yielding 2.18×10⁶ cells⋅mL^-1 with a viability of 94.19%. In PEG-mediated transient transformation， the optimal conditions were determined to be 40% PEG 4000 treatment for 30 min， 10 μg of plasmid DNA， and 0.6 mol⋅L^-1 mannitol. Under these conditions， the transformation efficiency reached 58.03%. Significant differences existed in the optimal preparation conditions for protoplasts derived from different tissues of A. paniculata， emphasizing the need for tissue-specific optimization. This study established an efficient protoplast preparation and transient transformation system forboth cotyledons and root callus of A. paniculata， providing a reliable technical platform for future gene function analysis and cell biology research in this medicinal plant.

To elucidate the establishment of combinational dormancy in Euscaphis konishii seeds from a developmental perspective， seeds collected from trees at the full fruiting stage were used to systematically examine seed growth and developmental progression at different post-anthesis stages. Dynamic changes in water uptake capacity， hardseededness， major storage reserves， and endogenous phytohormone contents were also analyzed. The results showed that： （1）During the early developmental stage（30-60 days after anthesis， DAA）， seed volume increased rapidly， whereas growth stabilized during the middle（60-120 DAA） and late stages（120-150 DAA）. Embryo structural differentiation became evident at 90 DAA， accompanied by gradual lignification of the seed coat and continued endosperm accumulation. At 120-150 DAA， seed size and external morphology were largely stabilized； however， embryo cells remained densely organized. （2）Throughout development， dry matter content increased steadily， while moisture content progressively declined. Hard seededness rose sharply after 90 DAA and exceeded 50% at 150 DAA. （3）Soluble sugar content was relatively high during early development but remained low after 90 DAA. In contrast， soluble protein， crude fat， and starch accumulated significantly during the later stages. Activities of α- and β-amylase exhibited a “decrease-increase-decrease” pattern， whereas peroxidase（POD） activity increased markedly after 90 DAA. （4） Abscisic acid（ABA）， brassinolide（BR）， and gibberellic acid（GA₃） displayed a biphasic pattern characterized by “increase-decrease-increase-decrease” during seed development. Auxin（IAA） and zeatin riboside（ZR） content increased significantly during the middle stage， and the ratios of IAA/ABA and ZR/ABA peaked at 90 DAA then declining with the subsequent re-accumulation of ABA. （5）Principal component analysis（PCA） indicated that early seed development was primarily associated with moisture content， soluble sugar content， and ABA content， whereas the middle-to-late developmental stages were mainly correlated with starch content， crude fat content， soluble protein content， POD activity， and IAA content. Overall， hardseed formation， shifts in carbon and nitrogen storage reserves， and coordinated hormonal regulation collectively contributed to the establishment of combinational dormancy in E. konishii seeds during development.

To explore the alleviative effect of exogenous gibberellin（GA₃） on the inhibition of seed germination of Agastache rugosa under salt stress， seeds of wild A. rugosa were used as materials to analyze the effects of salt stress simulated by NaCl solution on seed germination. Furthermore， transcriptome sequencing was performed on seeds at germination stages with significant physiological changes to elucidate the molecular mechanism of exogenous GA₃ regulating the response of A. rugosa seeds to salt stress from the gene expression level. The results showed that NaCl stress significantly inhibited seed germination， aggravated membrane lipid peroxidation and osmotic imbalance， induced oxidative damage， and disrupted normal physiological and metabolic processes. Treatment with 150 mg⋅L^-1 GA₃ alleviated membrane lipid peroxidation and osmotic stress， regulated the antioxidant system， and thus mitigated the inhibitory effect of salt stress on seed germination. Transcriptome analysis revealed that under salt stress， differentially expressed genes were significantly enriched in plant hormone signal transduction， starch and sucrose metabolism， and mitogen-activated protein kinase（MAPK） signaling pathway， indicating that these pathways play key roles in plant salt stress responses. Under GA₃ treatment， differentially expressed genes were mainly enriched in photosynthesis， phenylpropanoid biosynthesis and carbon fixation pathways， suggesting that GA₃ may alleviate salt stress by promoting energy metabolism and secondary metabolism. In addition， GA₃ significantly reduced salt stress-induced oxidative damage and metabolic imbalance by inhibiting ROS-related genes such as WRKY33， OXI1 and CALM， and regulating the ABA signaling pathway gene PP2C and jasmonic acid signaling pathway gene JAR1-4-6. This study confirmed that exogenous GA₃ could enhance salt tolerance and improve germination rate of A. rugosa seeds through synergistic effects of multiple pathways， such as alleviating oxidative damage and regulating key genes and metabolic pathways.

Horned galls constitute the primary variety of Chinese gallnuts and are typically harvested before dehiscence. Investigating the dehiscent mechanism of horned galls provides theoretical support for optimizing Chinese gallnut harvesting strategies and enhancing horned galls yield and quality. Using horned galls as experimental material， comprehensive analyses on paraffin section histological structure， hormonal （gibberellic acid and abscisic acid） levels， and transcriptional and metabolomic correlations were conducted on indehiscent and dehiscent horned galls at early-（C）， mid-（Z）， and late stages（M）. Results showed that indehiscent horned galls exhibited smaller parenchyma cells （mean diameter（31.40±2.38） μm）， more upper epidermal cells， and thicker epidermis. Dehiscent horned galls showed significantly enlarged parenchyma cells（mean diameter （93.60±7.10） μm）， reduced vascular bundles， and smaller schizogenous duct. In plant hormones within horned galls， both ABA and GA levels increased with gall dehiscent progression. Indehiscent horned galls exhibited lower contents（9.20 and 5.41 ng⋅g^-1）， while galls in the late dehiscent stage（M） showed higher levels （16.35， 10.94 ng⋅g^-1）. Transcriptome analysis revealed 2 064 differentially expressed genes between indehiscent and dehiscent horned galls， primarily enriched in the pathways such as plant hormone signaling and starch/sucrose metabolism. Significant differences were observed in the expression of GA20OX， ZEP， NCED and AAO genes during ABA and GA synthesis. Metabolomics identified 99 significantly differentially expressed metabolites（74 up-regulated， 25 down-regulated）， predominantly enriched in polyketide sugar biosynthesis and terpenoid skeleton biosynthesis pathways. Integrated analysis revealed that horned galls dehiscence involved in the coordinated action of multiple genes and metabolites， with differentially expressed genes and metabolites significantly enriched in pathways including phenylpropanoid biosynthesis and plant hormone signaling. Changes in cell volume and vascular bundle size occurred during horned galls dehiscence. Multiple pathways collectively drived horned galls dehiscence， with significant contributions from phenylpropanoid biosynthesis， flavonoid biosynthesis， starch and sucrose metabolism， and plant hormone signaling.

By investigating metabolite levels， enzyme activities， and gene expression associated with polysaccharide synthesis in the leaves and roots of Codonopsis pilosula under moderate drought conditions， this study amied to reveal the differential regulatory mechanisms governing polysaccharide synthesis in the tissues. During the flowering period， plants were subjected to two treatments：normal moisture（CK， 0% PEG-6000） and moderate drought（DH， 15% PEG-6000）. Samples were collected at 7， 14， and 21 days post-treatment. Using ultraviolet spectrophotometry， high-performance liquid chromatography（HPLC）， and high-throughput sequencing， we quantified the levels of metabolites involved in the polysaccharide synthesis pathway， enzyme activities， and gene expression in root and leaf tissues of C. pilosula. Results indicated that under moderate drought conditions， the levels of upstream metabolites—sucrose， fructose， and glucose—differred between leaves and roots. Specifically， the proportion of glucose increased in roots， whereas it decreased in leaves. Enzyme activities in the polysaccharide synthesis pathway also exhibited distinct tissue-specific responses： sucrase activity increased in both tissues， while the activities of monosaccharide conversion-related enzymes（galE， GAE， UXS1， and UER1） increased in leaves but decreased in roots. Moreover， significant changes in sucrase activity occurred earlier in leaves than in roots. Gene expression analysis further revealed tissue-specific differences in the regulation of polysaccharide synthesis. Among the 10 sucrose invertase regulatory genes， 2 were upregulated and 3 downregulated in leaves， whereas 6 were upregulated and 1 downregulated in roots. For the 14 genes encoding monosaccharide conversion enzymes， 7 were upregulated and 2 downregulated in leaves， compared to 2 upregulated and 5 downregulated in roots. Pearson correlation analysis showed that under moderate drought， the number of genes positively correlated with enzyme activity significantly increased in both tissues. Specifically， gene expression in leaves was positively correlated with monosaccharide conversion enzyme activity， whereas gene expression in roots was positively correlated with sucrose transferase activity. Collectively， moderate drought differentially regulated polysaccharide synthesis in C. pilosula leaves and roots by modulating upstream metabolite levels， sucrose transferase activity， and monosaccharide conversion-related gene expression， thereby controlling tissue-specific polysaccharide synthesis and accumulation.

To investigate the chemical composition and diversity of floral scent volatiles in plants of the genus Calycanthus，the floral scent compounds of nine Calycanthus species or varieties were analyzed using a combination of headspace solid-phase microextraction（HS-SPME） and static headspace（HS） coupled with gas chromatography-mass spectrometry（GC-MS）. Principal component analysis（PCA） and cluster analysis were employed to compare and evaluate the diversity of volatile compounds in the flowers of Calycanthus plants. The results showed that the numbers of volatile compounds detected in the flowers of C. chinensis， C. floridus and C. floridus ‘Athens’ were 16， 21，and 23（by SPME） and 5， 21，and 23（HS）， respectively. The volatile profile of C. chinensis was dominated by alkanes（HS-SPME） or terpenes（HS）， while that of C. floridus consisted mainly of esters， especially ethyl acetate. The volatile compositions of C. floridus ‘Athens’ were more diverse， including ethyl acetate， ethyl isobutyrate， ethyl butyrate and ethyl isobutyrate. Among the hybrid varieties， except for ‘Meixia’ which was rich in terpenes， the others contained relatively high levels of esters. The order of ester content from high to low was ‘Hongyun’， ‘Venus’， ‘Hongxiao’， ‘Fencan’， ‘Xiaodie’ and ‘Meixia’.PCA revealed that the volatile compounds of C. chinensis were the most distinct from those of the other Calycanthus plants， whereas the hybrid varieties showed greater similarity to the female parents（C. floridus and C. floridus ‘Athens’）. Cluster analysis of the volatile compounds obtained by the two methods indicated that the static headspace approach corresponded more closely to the genetic relationship among the tested Calycanthus plants.Specifically，hybrids from the same cross combination（‘Fencan’， ‘Xiaodie’， ‘Meixia’ and ‘Hongyun’ ） clustered together with their parents C. chinensis and C. floridus， while they were separated from C. floridus ‘Athens’ and its hybrid offspring（‘Hongxiao’ and ‘Venus’）. Based on the floral volatile composition results， C. floridus and C. floridus ‘Athens’ were rich in ester volatile compounds， suggesting their potential for development of fragrance chemicals and applications in aromatic gardens.

Phyllosphere microorganisms play crucial roles in host plant growth and development， disease resistance， stress tolerance， and ecosystem functions. However， the differences in phyllosphere microbial communities among different hosts and their underlying mechanisms remain unclear. This study focused on three plant species within the Inner Mongolia grassland ecosystem： Leymus chinensis（Poaceae）， Vicia sativa（Fabaceae）， and Aster altaicus（Asteraceae）. The diversity and community structure of bacteria and fungi in the phyllosphere were analyzed by using high-throughput sequencing technology. Additionally， the influence of key leaf traits-total carbon， total nitrogen， total phosphorus， chlorophyll content， and specific leaf area on these microbial communities was investigated. Results indicated significant host species specificity in phyllosphere microbial community structure. The α-diversity of both bacterial and fungal communities was highest on L. chinensis. The phyllosphere of L. chinensis was dominated by potentially beneficial bacteria such as Bacillus species， with relatively low abundance of pathogenic bacteria， although it also harbored potential pathogenic fungi. In contrast， the phyllosphere of V. sativa was enriched with nitrogen-fixing bacteria such as Sphingomonas and Methylobacterium-Methylorubrum. The fungal community in the phyllosphere of A. altaicus simultaneously contained pathogenic fungi such as Alternaria， and biocontrol fungi such as Epicoccum. Redundancy analysis revealed that leaf total phosphorus content significantly influenced both bacterial and fungal communities， whereas total nitrogen content and specific leaf area primarily affected fungal community variation. In conclusion， host leaf structural and nutrient traits are key determinants shaping phyllosphere bacterial and fungal communities. This study provides theoretical support for understanding the relationship between grassland plants and their phyllosphere microbiome， as well as their ecological adaptation strategies.

To address the breeding challenges of simultaneous selection for yield and quality， along with the high costs and low efficiency of full phenotypic identification in processing potatoes， this study established an efficient comprehensive evaluation system and a simplified early-generation prediction model. An F₁ population comprising 267 individuals， derived from the cross of ‘Atlantic’בLucinda’， was utilized to conduct phenotypic measurements and genetic analysis of 24 traits over two consecutive years. The results indicated that all traits in the population exhibited extensive variation—with coefficients of variation（C_V） ranging from 14.68% to 100.97%—and followed a continuous normal distribution， conforming to the quantitative genetic patterns controlled by minor polygenes. Notably， starch content and yield demonstrated significant positive heterosis and high broad-sense heritability. Through principal component analysis（PCA）， nine comprehensive indicators were extracted（cumulative variance contribution rate of 84.80%）. Combined with fuzzy membership function and hierarchical cluster analysis， 17 elite clones with high processing potential were successfully identified， five of which reached stringent processing quality standards. Moreover， the least absolute shrinkage and selection operator（LASSO） regression algorithm was introduced to precisely screen five core indicators， including cohesiveness and reducing sugar content， from the 24-dimensional dataset to construct a simplified model for efficient early-generation screening. This study provides reliable methodological support for the efficient breeding and germplasm evaluation of processing potato varieties.

Phosphorus（P） predominantly exists in forest soils as insoluble forms（such as inorganic and organic phosphorus）， and its low availability is a major factor limiting tree growth. Pinus sibirica， a key constructive species of the cold-temperate coniferous forest， faces challenges when its seedlings are transplanted to the acidic soils of the Greater Khingan Mountains， where insufficient available phosphorus adversely affects seedling survival and growth. To explore the adaptation mechanisms of P. sibirica to insoluble P， a pot experiment was conducted using 2-year-old seedlings as test material. Treatments included a control（no P addition） and three P addition levels-50% （17.40 mg⋅kg^-1）， 100% （34.80 mg⋅kg^-1）， and 200% （69.60 mg⋅kg^-1）-applied via four different P sources： calcium phytate， lecithin， aluminum phosphate， and iron phosphate. Seedling responses in biomass allocation， root morphology， and whole-plant phosphorus use efficiency（PUE） were analyzed. The results showed that： （1）Different P sources significantly affected seedling growth（P<0.05）. The iron phosphate treatment -particularly at 200% P addition level-significantly promoted biomass accumulation in all organs and total seedling biomass， whereas organic P sources（calcium phytate and lecithin） had no significant promoting effects. （2）PUE was significantly influenced by the interaction between P source type and level（P<0.05）. The highest PUE occurred under the 50% iron phosphate-addition level and declined with increasing levels； in contrast， PUE remained low and showed no significant trend under organic P source treatments. （3）Root morphology exhibited plasticity in response to insoluble P stress. Compared with the control， all P application treatments increased the specific root length and specific surface area of first-order roots but reduced their tissue density. Low-level iron phosphate induced a resource-acquisition strategy（characterized by high specific root length and low tissue density）， whereas a conservative strategy predominated at high P-addition levels. （4）A comprehensive evaluation indicated that the 200% iron phosphate treatment achieved the highest composite score， followed by 200% aluminum phosphate- and 100% lecithin-addition level， indicating that inorganic P sources-especially iron phosphate-are more conducive to P. sibirica seedling growth. In conclusion， P. sibirica enhanced its phosphorus acquisition capacity by modulating root morphological traits， adjusting biomass allocation patterns， and optimizing PUE， with iron phosphate being the dominant P form efficiently utilized by this species. In future afforestation and tending practices， iron phosphate is recommended as the preferred phosphorus fertilizer for P. sibirica seedlings， and fertilization strategies should adhere to the principle of “low concentration for root development promotion and high concentration for aboveground growth promotion”. This study provides scientific guidance for improving seedling quality and afforestation survival rates of P. sibirica in acidic soil regions.

The temporal dynamics of forest growth processes have become a critical component in evaluating terrestrial carbon cycle feedbacks. However， a systematic understanding of the coupling-decoupling patterns between intra-annual normalized difference vegetation index（NDVI） and radial growth phenology， as well as their response mechanisms to environmental factors， remains lacking. To address this， the present study focused on Pinus koraiensis plantations and Larix gmelinii plantations in Northeast China， employing continuous stem radial growth（SRG） monitoring， UAV-derived NDVI data， and meteorological observations to analyze the phenological characteristics and differential environmental responses of the two species during 2023—2024. The results demonstrated that L. gmelinii exhibited an “acquisitive” growth strategy， with SRG onset occurring 13-37 days earlier than that of P. koraiensis， and peak growth rates （22.40-32.34 μm⋅d^-1） consistently exceeding those of P. koraiensis （18.06-25.40 μm⋅d^-1）. In contrast， P. koraiensis displayed a “conservative” strategy characterized by a relatively concentrated growth period. SRG and NDVI phenology were highly synchronized in P. koraiensis， with a time lag of only 6-7 days between their onsets. Conversely， a pronounced decoupling was observed in L. gmelinii， where SRG initiated substantially earlier than NDVI but also ceased considerably sooner. Furthermore，the environmental response patterns of SRG and NDVI in P. koraiensis were highly consistent， both showing significant correlations with soil moisture and temperature， air temperature， and atmospheric humidity（r≥0.4， P<0.01）. In L. gmelinii， however， the responses diverged： NDVI was predominantly driven by air temperature（r≥0.4， P<0.01）， while SRG was jointly constrained by soil moisture， soil temperature， and atmospheric humidity（r≥0.4， P<0.01）. Collectively， this study reveals functional divergence between evergreenand deciduous conifer species in the coupling mechanisms between growth rhythms and NDVI dynamics， as well as in their sensitivity to environmental drivers， indicating that the coupling between canopy phenology and structural growth is species-specific.