Ancient trees in urban areas are affected by their own and environmental factors， resulting in growth restriction. Inoculation with indigenous dominant arbuscular mycorrhizal（AM） fungi in the rhizosphere soil of ancient trees may be a new method of ancient tree rejuvenation. Two indigenous AM fungal mycorrhizal agents（Claroideoglomus lamellosum and Funneliformis mosseae） were screened and propogated from the rhizosphere soil of Celtis sinensis trees in Shanghai， and were verified by inoculation into pots of C. sinensis seedlings. The results showed that plant height， stem diameter and leaf area of the inoculated seedlings increased significantly compared to the control， and the number of leaves also increased significantly. The mixed inoculation had a significant effect on the biomass of the whole plant and number of root tips. The accumulation of nitrogen（N） and phosphorus（P） nutrients， photosynthetic capacity and chlorophyll content of the seedlings were improved as compared with that of the control， respectively. Inoculation with both strains enhanced the activities of superoxide dismutase （SOD）， peroxidase （POD）， and catalase （CAT） in leaves and enhanced the resistance of live seedlings. Based on a comprehensive evaluation of the fuzzy membership function， an optimal inoculation strategy for promoting the growth of ancient C. sinensis seedlings was identified as FM+CL. This work provided a valuable reference for the application of indigenous AM fungi agents in the rejuvenation of ancient trees.

Germin-like proteins （GLPs） are a class of highly conserved stress-responsive proteins that can specifically respond to symbiotic interactions. This study， based on the whole-genome information of maize B73， used bioinformatics approaches to identify and analyze the characteristics of the ZmGLP gene family. The expression patterns of ZmGLP genes during arbuscular mycorrhizal fungi（AMF） symbiosis were examined by using transcriptome data. This study identified a total of 45 ZmGLP genes， which were distributed across nine chromosomes， with 25 of the genes being tandem duplications. By analysis of a phylogenetic tree， ZmGLP genes were classified into five distinct subfamilies. Notably， there were significant differences in tissue expression patterns among different ZmGLP genes. Promoter cis-element analysis showed that ZmGLP promoters contained elements responsive to light， stress， and growth and development. Interestingly， the promoter of ZmGLP4-8 contained the mycorrhiza-responsive element MYCS， and 20 ZmGLP promoters contained the potential mycorrhiza-responsive element GCCGGC. Analysis of transcriptome data from maize roots at different days after inoculation with AMF revealed that the expression of 12 ZmGLP genes was significantly changed following inoculation with AMF. Among them， ZmGLP3-3， ZmGLP4-8， ZmGLP4-16， ZmGLP4-20， ZmGLP5-1， and ZmGLP6-1 were significantly upregulated in expression during the late stage of symbiosis. These genes were located in different evolutionary branches compared to the reported symbiosis-related GLP genes， suggesting that these genes may be involved in functions related to the late stage of mycorrhizal symbiosis. Functional studies of ZmGLP3-3 showed that， compared to wild-type maize plants， the mycorrhizal symbiosis rate of the mutant zmglp3-3 was significantly reduced. In summary， this study provided a comprehensive theoretical basis for the exploration of symbiosis-related ZmGLP genes in maize， offering insights into their potential roles and functions in plant-fungal interactions.

This study aimed to explore the influence of changes in soil physicochemical properties caused by arbuscular mycorrhiza（AM） symbiosis on carbon component accumulation in Karst rocky desertification soils. Native tree species Fraxinus malacophylla was selected as the host plant. Four AM inoculation treatments were set up as following： Funneliformis mosseae+agro-bio-fertilizer（FM）， Claroideoglomus etunicatum+agro-bio-fertilizer（CE）， Rhizophagus intraradices + agro-bio-fertilizer（RI）， and control（CK， only agro-bio-fertilizer and without AM fungi inoculation）. The coupling relationship between the temporal-spatial dynamics of carbon components（total organic carbon， microbial biomass carbon， and readily oxidizable organic carbon） contents and soil physicochemical properties under inoculation treatments was explored. The results showed that：（1） AM fungal inoculation significantly increased the accumulation of soil carbon components（P<0.05）. Compared with the control， the average increment of soil carbon components under inoculation treatments was ranked as： RI（38.05%-139.34%）>CE（19.96%-88.52%）>FM（9.56%-22.95%）.（2）The seasonal changes of each carbon component content under inoculation treatments presented a “single peak” pattern， with the maximum peak appearing in June. The content of each carbon component decreased along with soil profile， and the amplitude of CE was the largest（15.70%-67.44%）.（3）AM fungal inoculation significantly affected the accumulation of organic carbon components due to significant changes in soil temperature and water content（P<0.05）. Compared with the control， the ratio of increase in soil temperature and water content under inoculation treatments was listed in a decreasing order of RI>CE>FM. Polynomial regression analysis indicated that total organic carbon content in soils significantly increased with the increase of soil temperature and water content（P<0.05）. The explanatory powers of soil temperature and water content on the changes of soil carbon pool were different under different inoculation treatments， of which the explanatory power of soil temperature was listed in a decreasing order： RI（94.55%）>CE（93.47%）>FM（90.49%）； that of soil water content： RI（95.01%）>CE（90.06%）>FM（88.11%）.（4）Under inoculation treatments， soil organic carbon content was correlated negatively with soil pH and bulk density， and significantly positively with soil carbon components， soil temperature， water content， content of ammonium nitrogen and nitrate nitrogen， colonization rate， and hyphal lodge density（P<0.05）. The principal component results indicated that soil carbon components， soil water content， and soil temperature were the main factors affecting accumulation of soil organic carbon content. Therefore， AM fungi symbiosis with F. malacophylla mainly significantly regulated the temporal-spatial dynamics of carbon pool accumulation in rocky desertification soil by mediating changes in soil carbon and nitrogen contents.

This study evaluated the antioxidant， antimicrobial， UV radiation resistance properties， and secondary metabolite content of fermented extracts from 20 endophytic fungi of diverse plant origins to assess their potential in cosmetic applications. ABTS and DPPH radical scavenging rates of fermentation broths and mycelial extracts were measured using microplate reader colorimetry， while ferric ion reduction capacity was determined via FRAP assay. Antimicrobial activity was assessed using the Oxford cup method. The results indicated strong antioxidant activity in fermentation broths of strains XY1， YZ6， ZJ29， XG4-2， and ZBS49. ZJ29 exhibited the highest DPPH radical scavenging rate （93.62%）， while XY1 showed the highest ABTS radical scavenging rate （90.47%）. ZJ29 fermentation broth also demonstrated an ABTS radical scavenging rate >50% and the highest FRAP value （2 974.55 μmol⋅L^-¹）. Tyrosinase inhibition by ZJ29 and ZL18-1 mycelial extracts reached 60.62% and 98.10%， respectively， with ZJ29 fermentation broth showing the strongest inhibition（69.78%）. ZJ29 fermentation broth exhibited the highest inhibition against Staphylococcus aureus. The UVA and UVB absorbance of YZ6 and ZJ29 was higher than 2.8， and the UVA absorbance of YZ6 and ZJ29 was higher than 2.0 and 1.5， respectively. YZ6 mycelial extract also showed strong resistance to UVB and UVA， with absorbance of 1.5-2.5. YH3 and XY1 mycelial extracts contained the higher polyphenol （18.47 and 15.36 mg⋅g^-¹） and flavonoid （4.35 and 7.15 mg⋅g^-¹） content， respectively. ZL23 and ZJ29 had the higher triterpene content （16.79 and 11.20 mg⋅g^-¹， respectively）. In conclusion， ZJ29 mycelial extracts had superior antimicrobial， UV radiation resistance， and antioxidant activities， followed by YZ6 and XY1， highlighting their significant potential for daily chemical products.

Mixed-species plantations can promote soil nutrient cycling， productivity， and ecosystem functions. Mycorrhizal associations play important roles in affecting species coexistence and nutrient cycling in mixed plantations. However， our understanding on the effects of mixed tree species with different mycorrhizal types on soil microbial community associated with soil nutrients of Eucalyptus plantations remains limited. In this study， we conducted metagenomic sequencing to investigate the changes in soil microbial community structure and functions， co-occurrence networks between bacteria and fungi， and their relationships with soil nutrients for one monospecific Eucalyptus plantation and three mixed Eucalyptus plantations with different mycorrhizal tree species， including Dalbergia odorifera（arbuscular mycorrhizal and N₂-fixing， AM-NF）， Michelia macclurei（arbuscular mycorrhizal， AM）， and Quercus acutissima（ectomycorrhizal， ECM）. The results indicated that the mixed stands significantly increased the richness of soil microbial community， enhanced the abundance of genes related to soil nutrient cycling， and increased the complexity of microbial co-occurrence networks. The mixed plantations of Eucalyptus with D. odorifera had the highest soil microbial richness， relative abundance of bacterial community associated with aerobic chemoheterotrophy and fermentation， and the modularity of fungal-bacterial co-occurrence network； meanwhile， either the bacterial or fungal communities were significantly different from the other three plantations. The mixed Eucalyptus plantations with M. macclurei or Q. acutissima species had the highest abundance of microbial functional genes such as hydrocarbon degradation， nitrogen fixation， and methanotrophy. In addition， the microbial co-occurrence networks in the mixed Eucalyptus plantations with Q. acutissima have the highest number of edges， average degree， and network stability. The richness of key microbes in co-occurrence networks was closely correlated with soil \mathrm{N}{\mathrm{O}}_{\mathrm{3}}^{-} level. However， the richness of microbial community of the networks in the mixed Eucalyptus plantations with D. odorifera and M. macclurei was largely associated with soil \mathrm{N}{\mathrm{H}}_{\mathrm{4}}^{+} level.

This study investigated the effects of Lepista nuda inoculation at different doses on the growth of Pinus koraiensis seedlings and rhizosphere soil enzyme activity， aiming to provide technical support for cultivating mycorrhizal P. koraiensis seedlings and forestation. Four-year-old P. koraiensis seedlings were treated with four doses of L. nuda inoculant. Growth parameters， soil nutrient content， and rhizosphere soil enzyme activity were measured and analyzed. Correlation analysis was conducted to elucidate the responses of seedling growth and soil enzyme activity to L. nuda colonization. Key findings were that： （1）L. nuda colonization significantly enhanced seedling growth， at an optimal dose of 150 g⋅plant^-1， plant height， ground diameter， fresh weight， and dry weight increased by 29.07%， 25.69%， 38.16%， and 57.44%， respectively， compared to the control. Mycorrhizal colonization rate and root activity increased significantly in the inoculation treatment compared to the control. （2）Inoculation treatments exhibited higher soil nutrient content than the control， at a dose of 150 g⋅plant^-1， the content of soil organic matter， available nitrogen， total nitrogen， total phosphorus， and available phosphorus increased by 60.67%， 31.46%， 35.23%， 72.22%， and 35.91%， respectively. （3）All doses of L. nuda inoculationenhanced rhizosphere soil enzyme activity， with the maximum increment at a dose of 150 g⋅plant^-1. （4）Correlation analysis revealed significant positive relationships between mycorrhizal colonization rate and root activity， biomass（dry/fresh weight）， growth parameters（height/diameter）， the contents of soil organic matter， total nitrogen/phosphorus， available nitrogen， and activities of sucrase， urease， and phosphatase. Soil available phosphorus content was positively correlated with phosphatase activity， while available nitrogen content was positively correlated with content of soil organic matter， and activities of urease and phosphatase. In conclusion， L. nuda inoculation markedly promoted P. koraiensis growth by regulating soil enzyme activity and nutrient cycling， with 150 g⋅plant^-1 identified as the optimal inoculation dose. The findings of this study provided valuable references for the cultivation of mycorrhizal P. koraiensis seedlings and improvement of forest soil quality.

In this study， 10 lily species collected from 30 areas were used as materials to determine the polyphenols content and antioxidant activity in lily bulbs by colorimetry， and the contents of nitrogen， phosphorus and potassium in lily bulbs and soils were determined by Kjeldahl method and atomic absorption spectrometry method， respectively. The environmental conditions of collection areas were investigated to explore the application prospect of wild lily in the development of antioxidant functional foods. This work provided the reference for further development of lily resources. The results showed that the contents of polyphenols， flavonoids， total flavanols and total anthocyanins in 10 lily bulbs collected from 30 areas were significantly different（P<0.05）. The content of polyphenols in bulbs of the same lily species collected from different areas were significantly different（P<0.05）， indicating the differences in lily quality of provenances among the ecological regions. There were significant differences in DPPH radical scavenging ability， copper ion reduction ability， metal chelation ability and lipid peroxidation inhibition ability of 10 lily bulb extracts（P<0.05）， and the antioxidant ability of polyphenol extracts from wild lily bulb was better than that from cultivated Lilium davidii var. unicolor. The antioxidant activity of polyphenol extracts from the same lily bulbs collected from different areas were significantly different（P<0.05）， which indicated that the antioxidant capacity of lily origin was obviously “authentic”. The contents of N， P and K in 10 lily bulbs were significantly different（P<0.05）， and the contents of N， P and K in soils collected from collection areas were significantly different（P<0.05）. Correlation analysis showed significant or extremely significant correlations between polyphenols content and copper ion reduction ability， DPPH free radical scavenging ability and lipid peroxidation inhibition ability of lily bulbs. Polyphenol content and antioxidant capacity of 10 lily bulbs were correlated with environmental factors to different extents. The environmental factors of the collection areas had different effects on the content of polyphenols and antioxidant activity of lily bulbs， the annual precipitation and annual average temperature were dominant factors. The polyphenols content was significantly positively correlated with the annual minimum temperature， annual precipitation and annual average temperature（P<0.05）. The total anthocyanins content was significantly positively correlated with annual average temperature and wind speed（P<0.05）. The comprehensive evaluation of antioxidant properties of lily polyphenols by using the functional analysis showed that the antioxidant quality of wild lily bulbs was better than that of traditional edible L. davidii var. unicolor. Among them， L. sargentiae in Xinhua Village， Yanjing Township， Baoxing County， Sichuan Province， L. leucanthum in Hongyang Township， Zhenping County， Shaanxi Province and L. lancifolium in Chengguan Town， Ganggao County， Shaanxi Province showed the best comprehensive performances， the bulb extracts of lily species could be used as natural antioxidants for development and utilization.

Paeonia lactiflora is a perennial herbaceous plant of Paeonia genus in the Paeoniaceae family， widely distributed in northeast， north and northwest China， but its germplasm resources sharply decreased due to human destruction and environmental changes. To explore the rule of phenotypic variation and the phenotypic diversity， 256 individual plants from 12 natural populations of P. lactiflora in Great Khingan Mountains were used as materials， and the data on 23 phenotypic characteristics were collected， and the methods of Nested analysis of variance， Pearson correlation analysis， principal components analysis and cluster analysis were used， respectively. The results showed that the coefficient of variation and the mean Shannon-Wiener index of 15 quantitative traits such as plant height and crown width were 25.88%（12.34%-92.78%） and 1.843， respectively. The mean Shannon-Wiener index of eight quality traits such as leaflet type， the degree of leaflet retraction and flower color was 1.146. There were significant differences in 11 phenotypic traits among and within populations （P<0.01）， and the average phenotypic differentiation coefficient between populations was 25.72%. The correlations indicated that most of the 15 quantitative traits were significantly or extremely significantly correlated with each other. The flower diameter was negatively correlated with latitude， humidity and precipitation， but positively correlated with altitude， annual average sunshine hours and temperature； the number of petals was positively correlated with latitude， but negatively correlated with the average annual sunshine hours. The length of compound leaves was positively correlated with the average annual precipitation. The above results indicated that temperature and geographical factors had more impact on flower phenotypic traits than on stem and leaf phenotypic traits of P. lactiflora. Four principal components were extracted by principal component analysis and accumulative contribution rate was 88.678%. The 12 natural populations were divided into three categories by cluster analysis， the first category was P3 population and characterized by multi heads and large flowers type with highly ornamental value； the second category， including two populations P7 and P9， had bigger stem and leaf traits such as plant height， stem diameter， number of scape， compound leaves， and apical leaflets， compared to other populations， indicating the population had vigorous growth. The nine populations in the third category were characterized by compound leaves， short and narrow apical leaflets， wide flower diameter， and short flower stalks. The phenotypic diversity and variation levels of P. lactiflora in Great Khingan Mountains were high， and intra-populations variation was the main sources. In conclusion， this study analyzed the phenotypic diversity of P. lactiflora in Great Khingan Mountains and explored its phenotypic variation patterns， which provided a basis for better protection and utilization of P. lactiflora resources.

To explore the pollen morphological characteristics of Nymphaea and their taxonomic significance， the pollen of 113 species or cultivars from five subgenera and two trans-subgeneric hybrids of Nymphaea were used as materials and their pollen morphological characters were observed by scanning electron microscope. The results showed that： （1）The pollen of Nymphaea were all single grains， radially symmetric， and medium size（10.05-37.04） μm×（21.96-64.83） μm. （2）Among them， the pollen germination troughs of Nymphaea in 86 samples were zonoporate， 23 samples were anazonoporate， and 4 samples were anacolpate. （3）The pollen exine ornamentation included smooth， micro verrucous， rough， nodular， baculate， and caveola type. （4）The 113 samples of Nymphaea germplasms were clustered into five groups， of which the subgenus Nymphaea was characterized primarily by anazonoporate germination trough and nodular and baculate exine ornamentation， distinguished it from other subgenera. In conclusion， there were some differences in pollen size， germination trough type， and exine ornamentation among different subgenera and trans-subgeneric hybrids of Nymphaea， which might serve as auxiliary reference indicators for classification and provided palynological evidence for the study of genetic and phylogenetic relationship of Nymphaea.

To explore the environmental adaptation mechanisms of Caragana halodendron in leaf traits， to provide a theoretical basis for breeding superior varieties of C. halodendron， and protection of species diversity in desert areas， soil and water conservation， and desertification mitigation， the phenotypic variations among different populations and their relationships with environmental factors were analyzed respectively. The 108 individuals from 18 natural populations of C. halodendron were used as research materials， and 11 leaf-related traits and 28 environmental factors were collected. Pearson correlation analysis and principal component analysis were utilized to explore the variation patterns of leaf traits and their correlations with environmental factors. The results showed that： （1）There were remarkably significant differences in the leaf traits of C.halodendron among different populations. The variation coefficient of leaf traits ranged from 9.42% to 83.12% among the populations and 1.58% to 59.07% intra-populations. Through a detailed comparison of the variation coefficient of traits within and among populations， it was evident that the average coefficient of variation among populations（31.17%） for all traits was higher than that within populations（21.86%）. （2）Correlation analysis of leaf traits revealed significant positive correlation between traits related to leaf shape （leaf length， leaf width， leaf area， specific leaf area）（P<0.05）， and leaf water content showed a significant positive correlation with leaf shape traits（P<0.05）. （3） Four principal components extracted from trait principal component analysis accounted for a cumulative contribution rate of 91.13%. （4）The correlation analysis between leaf traits and environmental factors showed that leaf shape， rachis length， stipular spine length， and the number of leaflets were extremely significantly correlated with multiple environmental factors such as drought， precipitation， temperature， and soil（P<0.01）， whereas specific leaf area was only extremely significantly correlated with multiple environmental factors（P<0.01）. The variation in leaf traits reflects the adaptability of this species to arid and saline-alkali environments and the strategy of C. halodendron adapting to environmental pressure by adjusting traits such as leaf shape， rachis length， and leaf water content. This work provided important insights for understanding the adaptation mechanism of desert plants.

The characteristics and influencing factors of heart rot in ancient elm trees in Hohhot were studied， and protection strategies for ancient elm trees were proposed to provide a theoretical basis for their conservation. In this study， Picus³ stress wave trunk cross-sectional scanner and TRU tree radar detection system were used to determine the heart rot characteristics of 44 ancient elm samples in Hohhot by 1∶1 stratified random sampling method. Linear regression model was used to analyze the relationship between heart rot of ancient elm trees and health indicators， morphological indicators and environmental indicators， and to explore the related factors influencing heart rot of ancient elm trees. The results showed that the quantity proportion of heart rot grades of ancient elm trees in Hohhot was ranked from large to small as grade Ⅱ>Ⅲ>Ⅰ>Ⅳ， and the frequency of the beginning point of trunk heart rot was ranked from high to low as pith（S， 36 times）>trunk sapwood（B， 25 times）>middle trunk（Z， 14 times）. The distribution of root density in the vertical and horizontal directions was consistent， indicating that the closer to the trunk， the greater the root density. Among the influencing factors， trunk diseases（R²=0.302）， trunk pests（R²=0.234）， bark damage（R²=0.225）， soil compaction（R²=0.248） and heart rot index were significantly correlated（P<0.01）. Root growth space（R²=0.187）， crown growth space（R²=0.103） and root density（R²=0.121） were significantly correlated with heart rot index（P<0.05）. There was no significant correlation between trunk inclination（R²=0.011）， crown shape（R²=0.013） and heart rot index（P>0.05）. The heart rot of ancient elm trees in Hohhot initially occurred mainly in the pith and sapwood areas of the trunk， the heart rot was mainly caused by damage to the sapwood of the trunk in the early stage of heart rot， but the heart rot in the pith was more serious. The trunk health of the ancient elm trees gradually declined with the growth of the trees， and the decline rate accelerated when the trunk appeared rot or cavities. The heart rot of ancient elm trees had a significant correlation with health indicators and environmental indicators， but not with the morphological indicators of ancient trees. Root density was also an important factor affecting the heart rot of ancient trees. Therefore， the health status of ancient elm trees should be assessed in time， and intervention treatment and repair should be done timely， the tree body should be protected from damage， and internal damage detection in the trunk should be strengthened， the physical space required for the growth of ancient trees should be reasonably planned， and the soil should be loosened in time to ensure its sufficient growth space and nutrient supply， attention should be paid to the prevention and control of diseases and insect pests and the repair of bark damage of ancient elm trees， the occurrence of external environmental violations should be reduced， and the conservation effect of ancient trees should be improved.

Clarifying the relationship between the radial growth and neighborhood structure of trees is helpful to understand the subtleties of stand structure and to make forest management more quantitative and precise. The Larix olgensis and Quercus mongolica forests in Xiaobeihu Nature Reserve were taken as materials， and the radial growth and neighborhood structural parameters of different diameter classes of dominant and associated tree species were calculated respectively. The direct and indirect effects of neighborhood structure on the radial growth of trees with different diameter classes were explored by path analysis. The results showed that： whether as dominant or associated tree species， the radial growth of small diameter class trees of L. olgensis and Q. mongolica was lower than that of medium and large diameter classes. The radial growth of L. olgensis was lower than that of Q. mongolica in the small diameter class， but higher than that of Q. mongolica in the medium and large diameter classes. The radial growth of small and medium diameter trees was significantly correlated with neighborhood structure， but not for large diameter trees. Open comparison（O_P） and competition index（C_I） were the main factors affecting the radial growth of L. olgensis and Q. mongolica， and the effect of associated tree species was higher than that of dominant tree species. The effect of neighborhood structure on radial growth gradually decreased with the increase of diameter class. In addition， the indirect interaction between O_P and C_I also affected the radial growth of L. olgensis and Q. mongolica. Therefore， when forest management was carried out in this area， the small and medium diameter class trees should be selected to adjust neighborhood structure， mainly by improving O_P and reducing C_I.

To reveal the carbon fixation mechanism of poplar plantations with different ages and to investigate the relationship between carbon storage and environmental factors in the Yellow River Floodplain， the distribution patterns and influencing factors of carbon storage in the tree layer， herb layer， litter layer， and soil layer of grassland （CK） and four distinct-aged （10， 30， 40， 50 a） poplar plantations in the Yellow River Floodplain were examined by field surveys and indoor analysis， respectively. The results showed that the proportion of biomass in the herb layer of the poplar plantation decreased gradually， and the proportion of biomass in the tree and litter layers progressively increased with the increase of stand age. The ratio of biomass in the tree layer to total biomass was the highest （93.21% to 96.17%）， followed by the litter layer （3.99% to 3.20%）， and in the herb layer was the lowest（2.84% to 0.63%）. The average carbon content of the poplar plantations was the highest in tree layer of 50-a plantation（420.40 g⋅kg^-1）， in herb layer of 10-a plantation（365.86 g⋅kg^-1）， and in litter layer of 30-a plantation（398.67 g⋅kg^-1） and the average carbon content of soil layer increased significantly with the increase of stand age. The carbon storage of poplar plantation increased with age， and the distribution pattern was tree layer（975.81 t⋅hm^-2）>soil layer（275.06 t⋅hm^-2）>litter layer（38.01 t⋅hm^-2）>herb layer（19.19 t⋅hm^-2）， the soil layer and tree layer were the main components of carbon storage of poplar plantation， accounted for 95.31% to 97.46% of the total carbon storage. Correlation and redundancy analysis showed that tree height（H）， soil organic matter（SOM）， diameter at breast height（DBH）， and stand density （SD） were the main environmental factors influencing carbon storage in poplar plantations. The results can provide a theoretical basis and data support for the carbon sink function of poplar plantation forests and the management strategy of plantation forests in the Yellow River Floodplain.

Acer mandshuricum is a colourful leafy tree species with great ornamental value in Northeast China， but it is difficult to reproduce. The aim of this study was to improve the rooting rate of A. mandshuricum softwood cuttings and to clarify the relationship between stumping treatment and rooting of softwood cuttings. In 2023， the cross-sectional anatomical structure and growth index of twigs， the physiological and biochemical index of leaves， and the rooting index of softwood cuttings of Pc-2（stumped in 2022）， Pc-1（stumped in 2023） were observed， using the twigs of A. mandshuricum without stumping（Pc-CK） as a control. The results showed that： the rooting rate， average root length， average number of roots， and root effect index of Pc-1 softwood cuttings were higher than those of Pc-2（P<0.05） and Pc-CK（P<0.05）. The thickness of the epidermal and cortical collenchyma and the thickness of the xylem in the cross-section of their twigs from small to large were Pc-1， Pc-2 and Pc-CK（P<0.05）. The length， basal diameter， leaf area， leaf fresh weight， and water content of Pc-1 twigs were significantly higher than those of Pc-CK（P<0.05）. The net photosynthetic rate and stomatal conductance of Pc-1 leaves were significantly increased by 90% and 89%（P<0.05） respectively， compared to Pc-CK. The contents of chlorophyll a， carotenoid， soluble sugar， and soluble protein， as well as the activities of superoxide dismutase（SOD）， peroxidase（POD）， and catalase（CAT） in Pc-1 leaves were significantly higher than those of Pc-CK（P<0.05）. The contents of malondialdehyde（MDA）， total flavonoids， and total phenolics in Pc-CK leaves were significantly higher than those in Pc-1（P<0.05）. In conclusion， the stumping treatment made the twigs of A. mandshuricum rejuvenated， which promoted the rooting from softwood cuttings. The Pc-1 twigs showed better juvenile characteristics and rooting effect on softwood cuttings， which provided support for the softwood cutting propagation of A. mandshuricum.

To investigate the differences of flavor quality and soil influencing factors of Huangdu tomato（Solanum lycopersicum） produced by farmers and commercial base， the variety “Hezuo 903” of Huangdu tomato， which was planted in Nigang village of Anting Town and Baidikai base respectively， was used as experimental material， and tomato fruit and rhizosphere soil were collected separately. The fruit quality and related enzyme activities， relative expression of genes encoding the enzymes，as well as the enzyme activities， and the contents of nitrogen， phosphorus and potassium in soil were determined and analyzed respectively. The results showed that contents of soluble sugar， soluble protein and lycopene in tomato fruits grown in farmers’ planting greenhouse were increased by 62.1%-141.1%， 57.8%-66.1% and 36.6%-212.6%， respectively， compared with those grown in Baidikai base. The fruit titrable acid content was reduced by 51.2%-71.9%， but there was no significant difference in Vc content between the two groups. The activities of soil urease and sucrase in farmers’ planting greenhouse were significantly increased by 3.9%-106.9% and 28.1%-47.5%， but the acid phosphatase activity was significantly decreased by 33.3%-56.1%. The contents of total nitrogen and available potassium in soil of farmers’ planting greenhouse were decreased by 34.1%-44.8% and 76.5%-84.5%， respectively， and the content of available phosphorus in soil of farmers’ planting greenhouse 2 was significantly lower by 63.1% than that in B091 greenhouse. In addition， compared with other greenhouses， the sucrose synthetase activity in tomato fruits of farmers’ planting greenhouse 1 was significantly increased by 36.5%- 140.5%， and the fructokinase activity in fruits of farmers’ planting greenhouse 2 and B091 was significantly increased by 29.2%-73.1% and 40.7%-88.5% respectively. The expression levels of LeSS， LeFRK2， LeHXK3 and LeME genes in tomato fruits from farmers’ planting greenhouse 1 were significantly higher than those in Baidikai base， but the expression level of LePFK gene was the highest in the B077 greenhouse of Baidikai base. The expression of LeLYCB gene was the highest in the farmers’ planting greenhouse 2， the expression of LeLYCE gene was the highest in B085， and the expression of LePSY gene was the highest in farmers’ planting greenhouse. In conclusion， with the changes of soil enzyme activities， the contents of available nitrogen， phosphorus and potassium in soil were regulated， and the enzyme activities and the expression of genes coding the enzymes related to tomato fruit flavor quality were changed， which led to the differences in flavor quality of Huangdu tomato.

The floral bud development of Polygonatum cyrtonema was examined at various stages using paraffin sectioning techniques， the characteristics of megasporogenesis and microsporogenesis and the development process of male and female gametophytes were explored respectively， the fundamental data for the genetic improvement and breeding of P. cyrtonema was provided.The results showed that： （1）The anther wall was composed of epidermis， endothecium， middle layer and tapetum layer. The tapetum layer was secretory， with mature tapetal cells exhibiting binucleate or multinucleate structures. The mature endothecium displayed fibrous thickened. （2）During the meiosis of microspore mother cell， cytokinesis occurred through a continuous type， resulting in tetrads arranged symmetrically in a linear pattern. Most mature pollen grains were two-cell type， occasionally three-cell type. （3）Meiosis of the megaspore mother cell produced a linear tetrad， and the development of the embryo sac followed the Polygonum type. The reproductive cellular development in P. cyrtonema demonstrated similarities to other members of the Polygonatum genus. Notably， the presence of a secretory tapetum and the three-celled pollen grain suggests that P. cyrtonema might have a relatively advanced evolutionary status.

This study aimed to establish a system of the protoplast preparation in Pinus massoniana for the transient transformation of genes， so as to promote the study of gene function and the development of genetic transformation system in P. massoniana. The explants were selected from different developmental periods of P. massoniana， including needle leaf， hypocotyls and callus tissues. The effects of different enzymatic conditions on the isolation efficiency of protoplasts were explored. The protoplasts preparation process involving different types of tissues， different osmotic pressures and enzymatic hydrolysis time were optimized. The results showed that pine needle tissue in 0.5 mol⋅L^-1 mannitol osmotic solution for 6 h was the optimal condition for protoplasts extraction. Based on this， a transient transformation system of exogenous genes expression in P. massoniana protoplasts was constructed by comparing different transformation conditions. The optimized protoplast preparation and transformation system could significantly improve the quality and transformation efficiency of protoplasts， and the transformation efficiency of protoplasts was as high as 47.83% when using a polyethylene glycol （PEG）-mediated transformation method in P. massoniana. In summary， this study successfully constructed an effective protoplast isolation system for P. massoniana， which provides a reliable transient expression platform for analyzing gene functions in coniferous species.

GROWTH-REGULATING FACTOR（GRF） is a specific transcription factor widely found in plants， which plays an important role in plant growth and development and stress response. In this study， bioinformatics analysis of the birch（Betula platyphylla） GRF gene family revealed that the birch reference genome contained nine GRF gene family members with conserved WRC and QLQ structural domains， and prediction analysis of promoter cis-acting elements in the BpGRFs family genes revealed that it contained abundant elements related to growth and development， hormone metabolism and stress response. The qRT-PCR results showed that BpGRF4 was highly expressed in all tissues of birch， and Agrobacterium-mediated method was used to obtain birch overexpressing BpGRF4 lines（OE-1，OE-2，OE-3） and the role of BpGRF4 in the birch development was explored， and the BpGRF4 overexpression lines were significantly elevated in plant height， diameter of the ground， internode length， and branching length respectively. In addition， the area of cortex， phloem and core of OE-3 line were significantly increased， and the leaf epidermal cells were about 51.6% larger than that of the wild type. In conclusion， the growth and development of birch overexpressed BpGRF4 were positively regulated， which provided the theoretical basis for clarifying the GRF gene family function in the growth and development of birch.

Thermomorphogenesis is defined as a series of morphological changes that occur in higher plants when the temperature is higher than an optimal temperature and lower than the stress temperature. Among these morphological changes， hypocotyl elongation induced by high temperature has received the most attention and has been studied most deeply. SMALL AUXIN UP RNA（SAUR） gene family plays a key role in promoting growth and cell elongation. However， little is known about the molecular mechanism of high temperature regulation of SAURs. In this study， Arabidopsis Col-0 wild type， pif4-2 mutant and four transgenic plants were used as research materials. Real-time Quantitative PCR（qPCR）， chromatin immunoprecipitation（ChIP）， double luciferase reporter gene detection and phenotypic analysis were used to explore the molecular mechanisms of high temperature regulated SAUR1-SAUR4. The results were as follows： high temperature promoted SAUR1-SAUR4 transcription and this promotion required transcription factor PHYTOCHROME-INTERACTING FACTOR 4（PIF4）； transcription factor PIF4 binded to the E-box region in the promoter regions of SAUR1-SAUR4， and mild-high temperature enhanced these binding； auxin was downstream of PIF4 in the thermomorphogenesis signaling pathway； auxin signaling pathway was required for the regulation of SAUR1-SAUR4 by PIF4. These results indicated that high temperature regulated the transcription of these four genes by influencing the binding strength of PIF4 and SAUR1-SAUR4 promoter chromatin. This research deepens our understanding of the molecular mechanism underlying hypocotyl elongation downstream genes regulated by high temperature during thermomorphogenesis， thus enriching the theoretical basis of heat-resistant breeding.

The response of soil microbial community functions to land use changes is of key importance in the prediction of soil ecological functions. In order to clarify the effects of different land use patterns on bacterial communities in the black soil region， the soil bacterial community structure， co-occurrence network structure and functional genes in cropland， forest land and grassland in the northeastern black soil region were analyzed， respectively， and the interaction mechanisms among land use patterns， soil physicochemical properties， bacterial diversity， bacterial community structure， co-occurrence network and functional genes were explored using structural equation modelling. The results showed that there were significant differences（P<0.05） in soil physical and chemical properties and bacterial community structure among different land use patterns， and that the Shannon index and the average degree of co-occurrence network of forest land and grassland were significantly higher than that in cropland（P<0.05）. The proportion of positive correlation edges of bacterial co-occurrence network in forest land was higher than that in other treatments， there was a stronger synergistic effect between soil bacteria in forest land. Functional gene results showed that different land use patterns significantly altered functional gene abundance（P<0.05）. Structural equation modelling indicated that bacterial community structure had the greatest direct effect on functional genes， and land use practices had the greatest indirect effect on functional genes. In conclusion， this study further confirmed the effects of different land use patterns on bacterial communities， which provided a scientific basis for land management in the black soil area.