This study aimed to clarify the spatiotemporal heterogeneity of carbon stocks in black soil regions and the influencing factors，and reveal how land use change affected carbon storage，so as to enrich carbon stock estimation methods and provide reference for formulating appropriate carbon sequestration policies.

Harbin City，a representative black soil region，was the study area. The land use data and multi-source spatial carbon density data in 2000，2010，and 2020 were employed to reveal the change pattern of carbon stock using time series analysis. The center of gravity migration model，exploratory spatial data analysis，and coldspot/hotspot spatial statistical method were used to characterize spatial differentiation. The geographical detector model was applied to identify the intensity and interaction of influencing factors for carbon stock in the study area.

From 2000 to 2020，cropland and forestland were the dominant land use types in the study area，with pronounced changes occurred，and the areas of land conversion were from cropland and forestland （only second to land conversion from water area），mainly into construction land and unused land. These land use changes shaped the spatiotemporal distribution of carbon stocks，which decreased overall from 6.92×10⁸ t in 2000 to 6.60×10⁸ t in 2020. The center of gravity of carbon stock under land use change shifted 548.61 m southeastward in the study area，with the most pronounced migration distance between 2010 and 2020，reaching 451.36 m. Carbon stock hotspot areas based on land use changes were concentrated and became increasingly expanded，while coldspot areas remained relatively scattered and shrank. Carbon stock under land use change in the study area was commonly influenced by natural environmental and socioeconomic factors，with elevation，land use intensity，distance from county center，and slope exhibiting strong explanatory power. Factor interactions were predominantly characterized by dual-factor enhancement，and interactions between natural and socioeconomic factors explained change in carbon stock more effectively than interactions among factors within a single category.

Between 2000 and 2020，carbon stock under land use change in the study area generally declines，and carbon stock loss is primarily due to the conversion of high-carbon-sink land use types （water areas and forestlands） into low-carbon-sink land use types （unused land，cropland，and construction land），indicating that human-driven land use change has become a key factor influencing carbon stock. Furthermore，carbon stock change shows clear spatial clustering，underscoring the scale-dependent impact of human activities on spatial reorganization of carbon pools. The interaction between natural constraints and human disturbances is a dual-engine dri-ving model for carbon stock change，with elevation，distance from county center，slope，and land use intensity as critical influencing factors of spatial differentiation. Accordingly，it is recommended that cropland retirement should be prioritized in high-risk areas identified by the slope-distance coupling model.

This study aimed to investigate the effects of different plant Jiaosu nutrient solutions on yield and quality of Orah，providing reference for Orah production and fruit and vegetable waste valorization.

Diffe-rent plant Jiaosu nutrient solutions were uniformly sprayed on leaves of Orah trees at the fruit expansion-ripening stage. Plant Jiaosu nutrient solutions used on treatment A and treatment B were made from cull Orah fruits and discarded cabbage leaves，with an equal spray of purified water as the control treatment （CK）. Relative chlorophyll content （SPAD value），nitrogen content，phosphorus content，potassium content，amino acid content in leaves and fruits，fruit yield traits，and quality indicators under different treatments were determined. Correlation analysis was conducted on leaf indicators，fruit mass，and fruit quality indicators.

The two treatments of spraying plant Jiaosu nutrient solutions effectively increased the SPAD value of leaves，single fruit weight，and total amino acid contents in leaves and fruits，which were significantly higher than those of CK （P<0.05，the same below）；the treatment A exhibited better effects than treatment B. Spraying plant Jiaosu nutrient solutions significantly increased the nitrogen content of leaves，but had little effects on nitrogen content，phosphorus content，and potassium content in Orah fruits. Vitamin C content，soluble sugar contents，total sugar content，and sugar-acid ratio were positive indicators affecting fruit quality. The four indicators of treatment A were significantly higher than those of treatment B and CK；for treatment B，only the sugar-acid ratio was significantly higher than that of the CK，whereas the other three parameters showed no significant differences compared with CK （P>0.05）. In terms of the negative indicators affecting Orah fruit quality （total acid content and crude fiber content），treatment A had the lowest values of both indicators，which were significantly lower than CK. The correlation network diagram of indicators showed that spraying Jiaosu nutrient solutions might affect the yield and quality of Orah fruits indirectly by influencing SPAD value，nitrogen content，potassium content，and amino acid content of leaves.

Foliar spraying the two Jiaosu nutrient solutions increase yield and quality of Orah by influencing indicators such as chlorophyll content，amino acid content，and Jiaosu nutrient solutions prepared from fruits of the same plant species show better efficacy.

This study aimed to analyze the effects of different improvement measures on physicochemical properties and bacterial diversity of peach rhizosphere soil，providing theoretical basis for peach continuous crop obstacle alleviation and sustainable development of peach cultivation.

Replanted peach rhizosphere soil was used as the research object. Three treatments were established：deep tillage of original soil followed by rice rotation + natural grass （DR+NG），deep tillage of original soil followed by rice rotation + alfalfa grass （DR+PA），and deep tillage of original soil + natural grass （DT+NG）. Soil physicochemical property determination and high-throughput sequencing were used to analyze the composition and diversity of bacterial communities of rhizosphere soil in peach orchard under different improvement measures，and function prediction was performed.

The analysis results of soil physicochemical pro-perty showed that，compared with the DT+NG treatment，the DR+NG treatment significantly increased soil pH，alkali-hydrolyzable nitrogen，and organic matter content （P<0.05，same below），and significantly decreased electrical conductivity and available potassium content. Compared with the DR+NG treatment，the DR+PA treatment significantly decreased soil pH，electrical conductivity，alkali-hydrolyzable nitrogen content，and organic matter content while significantly increased available potassium content. Bacterial community analysis showed that，compared with the DT+NG treatment，the relative abundance of Bacteroidota，Crenarchaeota，Latescibacterota，NB1-j，and Nitrospirota significantly or extremely significantly （P<0.01） increased；compared with the DR+NG treatment，the relative abundance of Actinobacteriota，Desulfobacterota，Firmicutes，and Chloroflexi significantly or extremely significantly （P<0.01） increased. Soil microbial diversity showed significant differences among treatments. Compared with the DT+NG treatment，the ACE and Chao indexes under the DR+NG treatment increased by 7.30% and 6.90% respectively，the Simpson index extremely significantly increased by 44.09% （P<0.001），and the Shannon index extremely significantly decreased by 2.27% （P<0.001）；compared with the DR+NG treatment，the ACE，Chao，and Shannon indexes under the DR+PA treatment extremely significantly increased by 13.50%，13.30%，and 2.80% （P<0.001） respectively，and the Simpson index extremely significantly decreased by 25.68% （P<0.001）. Function prediction results showed that rice rotation and grass treatments significantly affected carbon and nitrogen cycling-related functions，and compared with the DT+NG treatment，relative abundance of nitrification function under the DR+NG treatment extremely significantly increased by 103.6% （P<0.01）；compared with the DR+NG treatment，relative abundance of chemoheterotrophy，aerobic chemoheterotrophy，and nitrogen fixation functions under the DR+PA treatment extremely significantly increased by 17.3%，22.0%，and 88.3% respectively （P<0.01）.

Deep tillage followed by rice rotation combined with alfalfa grass treatment can improve soil physicochemical properties and provide an ideal microbial environment for early peach growth. Compared with conventional natural grass and deep tillage alone，it shows better comprehensive improvement effects and can be applied in the renewal of old peach orchards.

This study aimed to investigate overall structure，key components，and working parameters of 4GL-KC98.6 whole-stalk sugarcane harvester，providing reference for optimizing operation performance of the whole-stalk sugarcane harvester.

A special leaf stripping channel test platform was built，and different sugarcane varie-ties were selected to carry out systematic experiments to analyze the effects of sugarcane morphology and environmental humidity on leaf stripping of 4GL-KC98.6 whole-stalk sugarcane harvester and determine the optimal parameter interval of leaf stripping roller rotation speed. Based on the self-designed automatic profiling mechanism，an adaptive ground cutting system was constructed，and the automatic lifting control of the cutterhead was discussed. The working performance of 4GL-KC98.6 whole-stalk sugarcane harvester was evaluated by field experiment.

The physical morphology of sugarcane markedly affected the operation performance of the leaf stripping device. When harvesting sugarcane in upright state and bending state，the leaf stripping roller rotation speed was controlled at 600-800 r/min and 700-900 r/min respectively，which could maintain low impurity rates and loss rates，thus achieving good leaf stripping performance. Environmental humidity also affected leaf stripping performance. The leaf stripping roller rotation speed was controlled at 400-600 r/min under low humidity conditions and 800-1000 r/min under medium and high humidity conditions，which could keep low impurity rates and loss rates. Based on the optimal stubble height in the sugarcane-growing areas of Guangxi，the automatic control scheme for cutterhead lifting was set as follows：when the distance between the cutterhead and the ground was 1-3 cm，the height of the cutterhead remained unmoved；when the distance was < 1 cm，the height of cutterhead was raised；when the distance was > 3 cm，the height of cutterhead was lowered. The field experiment results showed that，for the 4GL-KC98.6 whole-stalk sugarcane harvester，the average impurity rate was 2.71%，the average stump breaking rate 6.34%，the average loss rate 2.98%，the qualified cane rate 94.10%，and the qualified cutting height rate 95.80%. The overall operation performance indicators of the machine met the requirements of JB/T 6275-2019 Sugarcane Combine Harvester. Compared with the conventional manual harvesting efficiency （1.0-1.5 t/d），the average harvesting efficiency of 4GL-KC98.6 whole-stalk sugarcane harvester was 5.31 t/h，and the daily harvesting capacity was equivalent to the workload of about 40 workers.

By controlling the key working parameters of leaf stripping process of 4GL-KC98.6 whole-stalk sugarcane harvester and formulating the automatic control scheme of cutterhead lifting，the impurity rate and loss rate of sugarcane harvesting process can be effectively controlled，and the quality and efficiency of sugarcane harvesting can be improved.

This study aimed to predict the potential suitable habitats of Alpinia oxyphylla Miq. in China，clarify the correlation between climate change and its distribution，thereby providing a theoretical basis for its artificial cultivation，introduction，development，and utilization.

Based on the 62 distribution points of Alpinia oxyphylla Miq. and 19 environmental factors，the maximum entropy model （MaxEnt） was used to predict its potential suitable habitats under current and future （2050s and 2090s） climate change scenarios （SSP1-2.6 and SSP5-8.5）. The actual suitable habitats were calculated through overlay analysis with land use types. Key environmental factors were screened based on their contribution rates and response curves. Based on changes in suitable habitat area and centroid migration，the chan-ging trends in potential suitable habitats of Alpinia oxyphylla Miq. under future climate change were determined.

The current total suitable habitats of Alpinia oxyphylla Miq. in China was 37.59 × 10⁴ km²，mainly distributed in Guangdong，Guangxi，Hainan，Fujian，Taiwan，and Yunnan. The area of lowly suitable habitat was 24.67 × 10⁴ km²，the area of moderately suitable habitat was 10.09 × 10⁴ km²，and the area of highly suitable habitat was 2.83 × 10⁴ km² respectively. Overlay analysis was performed on geographical layers of forestland and shrubland，which showed that the actual suitable habitats of Alpinia oxyphylla Miq. was 21.56 × 10⁴ km². The four key environmental factors affecting the growth of Alpinia oxyphylla Miq. was in the order of contribution rate as minimum temperature of coldest month （73.5%） > precipitation of driest month （9.7%） > annual precipitation （6.2%） > mean diurnal temperature range （4.0%），with minimum temperature of coldest month being the dominant environmental factor. Under the SSP1-2.6 scenario，the suitable habitats of Alpinia oxyphylla Miq. generally showed an overall expanding trend. Under the SSP5-8.5 scenario，although the lowly suitable habitats continued to increase by the 2090s，the moderately and highly suitable habitats shrank sharply，resulting in a declining trend in the total suitable habitats. In addition，under the SSP1-2.6 scenario，the centroid of the suitable habitats of Alpinia oxyphylla Miq. in China showed no obvious east-west migration but exhibited a continuous northward migration trend. Under the SSP5-8.5 scenario，the centroid of suitable habitats rapidly migrated westward and then remained relatively stable in longitude，while continuously migrating northward in latitude.

Under future climate change scenarios，the distribution trends and area changes of suitable habitats of Alpinia oxyphylla Miq. in China will show different response patterns. The suitable habitats of Alpinia oxyphylla Miq. in Guangdong and Guangxi will continue to increase under the low radiative forcing scenario but shrink severely under the high radiative forcing scenario. Therefore，meteorological monitoring and artificial intervention should be strengthened，and changes in crop varieties should be considered in a timely manner. The suitable habitats of Alpinia oxyphylla Miq. in Fujian，Yunnan，and Guizhou will continue to increase. Planting trials should be conducted before introduction and cultivation in newly suitable habitats，while economic viability and feasibility should also be considered. The suitable habitats of Alpinia oxyphylla Miq. in Hainan and Taiwan remain relatively stable，but attention should be paid to the decline in suitable habitat levels caused by climate change. Artificial intervention measures should be taken in a timely manner based on environmental factors and meteorological monitoring results to ensure the quality of medicinal materials.

This study aimed to analyze the genetic diversity of phenotypic traits of tea germplasm resources from Jiuwan Mountain，Guangxi，providing theoretical reference for tea origin and evolution studies，superior gene mining，and germplasm innovative utilization and conservation.

A total of 120 tea germplasm resources from Jiuwan Mountain，Guangxi were taken as research materials. A total of 19 phenotypic traits of them （including 13 qualitative traits and six quantitative traits） such as tree architecture and leaf morphology were determined，and genetic variation analysis，correlation analysis，principal component analysis，and cluster analysis were performed to systematically evaluate the major phenotypic traits and their genetic diversity.

Most tea germplasm resources from Jiuwan Mountain，Guangxi，were shrubs （61.67%） and semi-arbors （35.00%）；semi-spreading type accounted for the largest proportion （45.00%），followed by erect type （30.00%） and spreading type （25.00%）. Leaf insertion angle was mainly flat type （70.00%）. Leaf color was dominated by green （74.17%），followed by light green （19.16%）. Leaf apexes were mainly acuminate （38.33%） and acute （36.67%）. Leaf bases were mostly cuneate （74.17%）. Leaf blades were mainly flat （57.50%） and involute （39.17%）. Leaf surfaces were mainly slightly convex （38.34%） and relatively smooth （30.00%）. Leaf margins were mainly flat （87.50%）. Leaf texture was relatively soft or brittle （each accounting for 34.17%）. Leaf serration density were mostly moderately （55.84%） and intensely （38.33%） dense；leaf serration depth was moderate （58.33%） or shallow （25.00%）；leaf serration sharpness was mainly sharp （47.50%） or moderately sharp （45.83%）. The average Shannon-Wiener diversity index （H'） of 13 qualitative traits was 1.31，with coefficients of variation ranging from 25.01% to 45.07%. The average H' of six quantitative traits was 2.03，and the coefficients of variation ranged from 13.83% to 38.63%. Correlation analysis showed that 11 pairs of traits had extremely significant positive correlations，nine pairs had significant positive correlations，10 pairs had extremely significant negative correlations，and 10 pairs had significant negative correlations. Principal component analysis extracted the first seven principal components with a cumulative contribution rate of 67.29%，and five superior germplasms with high comprehensive scores for leaves were screened according to principal component scores. Cluster analysis showed that the 120 germplasm resources were divided into seven groups at a Euclidean distance of 5.38：Group Ⅰ and Group Ⅱ had more germplasms，making up 75.83% of all materials；LZ099 and LZ110 in Group Ⅴ，along with LZ034 and LZ081 in Group Ⅲ，could serve as vital materials for tea breeding for their good characteristics such as big leaves and double buds.

Phenotypic traits of tea germplasm resources from Jiuwan Mountain，Guangxi show rich genetic diversity，with great development potential for breeding new distinctive tea varieties and innovative utilization of germplasm. Rare group conservation and exploration and utilization of core germplasms should be strengthened.

This study aimed to perform identification，subcellular localization，and expression analysis of the longan FLOE gene family members，explore the mechanism underlying the FLOE gene family during longan somatic embryogenesis and stress response，providing theoretical reference for molecular breeding of stress-tolerant longan.

Using the Arabidopsis thaliana FLOE family protein sequences as reference sequences，DlFLOE gene family members were identified from longan genome. Bioinformatic methods were employed to analyze their sequence characteri-stics. Real-time fluorescence quantitative PCR was utilized to analyze different early stages of somatic embryogenesis and expression patterns under hormones and abiotic stresses of DlFLOE gene family.

Three DlFLOE gene family members were identified and named DlFLOE1，DlFLOE2，and DlFLOE3 according to their positions on chromosomes. The number of amino acids encoded by DlFLOE family members ranged from 440 to 559，with relative molecular mass ranged from 48.36 to 61.25 kD，and theoretical isoelectric points of 5.51-6.16，indicating that they were all hydrophilic and unstable proteins. The DlFLOE2 protein located in the vacuole，while DlFLOE1 and DlFLOE3 proteins were located in nucleus. Phylogenetic analysis results showed that the DlFLOE3 gene clustered with the LITCHI022451.m1 gene of Litchi chinensis，indicating that the homologous genes of Sapindaceae were conserved. According to results of gene and protein structure analysis as well as collinearity analysis，the DlFLOE2 gene had five intron，and the rest genes contained two introns，with intron length showing difference between species；most members contained DUF1421 domain；a colli-near relationship was found between DlFLOE2 and DlFLOE3 genes，with the two genes located on different chromosomes and the Ka/Ks=0.261，suggesting that they had been under purifying selection during evolution. Promoter cis-element analysis and subcellular localization results showed that the promoters of DlFLOE family members contained elements responsive to light and drought stress；the DlFLOE1 gene had a strong positive response to high-concentration PEG and was located in nucleus，which was consistent with predictions from online software. Real-time fluorescence quantitative PCR detection results indicated that DlFLOE genes family members responded to different hormones and abiotic stress treatments，but their expression patterns varied.

The three FLOE gene family members identified from the longan genome exhibit functional differentiation and clear spatiotemporal specificity，showing important roles in stress response and hormone regulation for longan. The DlFLOE1 gene shows a strong positive response to high-concentration PEG，thus，it is suggested to be involved in drought-responsive pathways.

This study aimed to evaluate the breeding potential of the main cultivated sugarcane YZ0551 and YZ081609 in Yunnan and identify superior hybrid progenies，providing material and technological reference for germplasm resource utilization and new variety selection in sugarcane breeding.

A total of 437 materials from YZ0551，YZ081609，and their hybrid progenies were taken as research objects. Genetic variation analysis，correlation analysis，principal component analysis，cluster analysis，and comprehensive evaluation were performed for eight traits （six agronomic traits and two technological traits）.

The coefficients of variation of the eight traits ranged from 3.68% to 44.84%. The coefficients of variation for sugar yield and cane yield were the largest，which were 44.84% and 44.23% respectively. The genetic transmitting ability was 71.69%-104.49%，and the broad-sense heritability was 61.35%-96.72%. Correlation of different degrees was found among eight traits，among which cane yield and sugar yield had extremely significant positive correlations with single-cane weight and effective cane number （P<0.01，the same below），and cane yield had an extremely significant positive correlation with sugar yield，indicating that relationship between yield traits shall be considered comprehensively during breeding. Principal component analysis extracted yield factor 1，yield factor 2，and sugar factor，with a cumulative contribution rate of 84.966%. A total of 437 materials were divided into three groups：Group I was characterized with high yield and high sugar content，Group II had advantages in single-cane weight and cane diameter，and Group III had rich genetic variation but mediocre comprehensive performance. According to the comprehensive evaluation D value to evaluate performance of materials，the D value of the female parent YZ0551 was 0.4753，and the D value of male parent YZ081609 was 0.7102. Among the progeny materials，the number of materials with a D value greater than that of YZ0551 was 242；the number of materials with a D value greater than that of YZ081609 was four （V-315，V-317，8-292，and 8-208）；the D values of these four materials，along with other three materials （8-149，V-307，and V-309） were greater than 0.7000. The above seven materials all belonged to Group I，showing characteristics of high yield and high sugar content.

The traits of high sugar content and high yield of YZ0551 and YZ081609 are genetically stable，showing high breeding value，thus，they can be used as important parents for sugarcane breeding. The hybrid progenies of the two exhibit rich genetic variation for agronomic traits，among which V-315，V-317，8-292，8-208，8-149，V-307，and V-309 have superior comprehensive performance and can be used as parents for high yield and high sugar content. At the same time，variety comparison trials can be carried out to further breed superior new varieties. After years of field trials，the hybrid progeny 8-57 demonstrates superior characteristics of high yield，high sugar content，and lodging resistance；it is named YZ19519 and will participate in regional trials for new sugarcane varieties.

This study aimed to investigate the response characteristics of liver metabolism of Gymnocypris przewalskii under salt stress，so as to provide theoretical basis for enhancing environmental adaptability of Gymnocypris przewalskii after artificial proliferation and release and improving resource contribution rate.

Untargeted liquid chromatography-tandem mass spectrometry （LC-MS/MS） was employed to profile the liver metabolomic changes in juvenile Gymnocypris przewalskii exposed to different salinity （10‰，15‰，and 20‰），with individuals under 5‰ salinity stress as control group. Multivariate statistical methods were applied to screen differential metabolites and identify key metabolic pathways.

The survival rate statistics showed that juvenile Gymnocypris przewalskii maintained a survival rate ≥ 96% within 48 h of 5‰，10‰，and 15‰ salinity stresses，exhibiting robust tolerance，whereas all individuals died within 48 h of 20‰ salinity stress，suggesting that this salinity exceeded their tolerance limit. Principal component analysis （PCA） revealed that a clear separation in metabolic profiles between each salinity stress group and control group，with the separation degree of samples at the first and the second principal components intensifying as salinity increased. Within the tolerable salinity range （10‰-15‰），the metabolic pathways included biosynthesis of unsaturated fatty acids，glyoxylate and dicarboxylate metabolism，glycerophospholipid metabolism，choline metabolism in cancer，pyruvate metabolism，vitamin B6 metabolism，propanoate metabolism，and arginine and proline metabolism in liver of Gymnocypris przewalskii were significantly enriched （P<0.05，same below）. Under 20‰ salinity stress，the pathways included protein digestion and absorption，aminoacyl-tRNA biosynthesis，central carbon metabolism in cancer，biotin metabolism，carbon metabolism，pyruvate metabolism，and nicotinate and nicotinamide metabolism significantly enriched.

Gymnocypris przewalskii exhibits a clear metabolic threshold dependence in response to salt stress. Within the tolerable salinity，the organism primarily employs active regulation to maintain homeostasis through remode-ling lipid，energy，and amino acid metabolism；once the threshold is exceeded，the organism is forced to activate glutathione-centered antioxidant defense，accompanied by concurrent purine metabolic disturbances. Under extreme stress，Gymnocypris przewalskii faces a metabolic trade-off dilemma between “homeostasis maintenance and stress defense”.

This study aimed to comprehensively evaluate Bougainvillea germplasm resources in the dry-hot valley of the Jinsha River，providing theoretical reference for superior variety selection and new variety breeding of Bougainvillea in the dry-hot valley of the Jinsha River.

A total of 18 Bougainvillea germplasms were taken as research objects to measure 11 cultivar traits and five pigment content indicators. Public scoring and grouping by color category were performed. Comprehensive evaluation of Bougainvillea germplasms was conducted based on analysis of coefficient of variation （CV），cluster analysis，correlation analysis，principal component analysis （PCA），and membership function analysis.

The 18 Bougainvillea germplasms were divided into purple group，red group，orange-yellow group，pink group，and white group，and the CV of quantitative traits ranged from 28.05%-39.93%，with the largest CV for leaf width at 39.93% and the smallest CV for bract width at 28.05%. The CV of pigment content ranged from 26.52% to 46.62%，with the largest CV for procyanidin content at 46.62% and the smallest CV for chlorophyll a content at 26.52%. Correlation analysis results showed that the procyanidin content had extremely significant negative correlations with betacyanin content and flower color （P<0.001），with the coefficient of correlation of -0.87；flower color had an extremely positive correlation with betacyanin content （P<0.001），with the coefficient of correlation of 0.88；public scoring had significant （P<0.05） or extremely signficant （P<0.01） correlations with flower color，leaf length，procyanidin content，and betacyanin content，with the most pronounced correlation with flower color. Cluster analysis results showed that the 18 germplasms into four major groups，among which Group Ⅱ only included Bougainvillea cv. Miss Manila，demon-strating that this cultivar showed greater uniqueness compared with other germplasms；the 11 cultivar traits and five pigment content indicators were divided into four major categories：the first and second categories showed trait characteristics，and the third and fourth categories showed pigment content characteristics. Principal component analysis（PCA） showed that，six principal components from the first to the sixth principal component were extracted at the standard of eigenvalue greater than 1，with the cumulative contribution rate of 82.85%，and the traits that exhibited the highest factor loadings across the six principal components （PC1-PC6） were flower color，bract width，leaf length，leaf width，leaf color，and chlorophyll a content. By calculating the membership function values，Bougainvillea cv. Killie Campbell had the highest score. According to calculation combined comprehensive PCA with membership function method，the 18 Bougainvillea germplasms were divided into four grades，and the Grade I included Bougainvillea cv. Miss Manila，Bougainvillea cv. Mrs. Butt，and Bougainvillea cv. Killie Campbell.

According to comprehensive evaluation of PCA and membership function method，three Bougainvillea cultivars （Bougainvillea cv. Miss Manila，Bougainvillea cv. Mrs. Butt，and Bougainvillea cv. Killie Campbell） have high scores. As they have big bracts，big leaves，and bright bracts，they are suitable to be popularized and cultivated in the dry-hot valley of the Jinsha River.