Six different germplasms of Aquilaria sinesis (Lour.) Spreng. (three approved improved varieties: Haixiang 1, Haixiang 2 and Haixiang 3, and three pre-varieties: Piyou type, Big leaf type and Nangpao type) were used as the research objects. Among them, Piyou type came from Jieyang city, Guangdong province, Big leaf type species came from Ding'an county, Hainan province, and the rest came from Wenchang city, Hainan province. The pH, starch content, soluble sugar content, soluble protein content and cellulose content of the wood from trunk were determined by GB/T 6043—2009 (Determination of wood pH), anthrone colorimetric method, Coomassie bright blue method and nitric acid-ethanol method respectively. SPSS 26.0 was used to conduct variance analysis, multiple comparison analysis (Waller-Duncan method, LSD method) and Pearson correlation analysis on the measurement results of the above five indicators. The test results indicated that the wood from the trunk of six different A. sinensis germplasms were acidic, and the pH ranged from 5.40 to 6.06. The pH of the trunk was the highest in Haixiang 3 and the lowest in Big leaf type. The starch content ranged from 13.16 to 33.85 mg/g. Among them, the trunk starch content of Big leaf type was the highest, and that of Haixiang 3 was the lowest. The soluble sugar content ranged from 3.60 to 20.16 mg/g. Among them, the trunk soluble sugar content of Big leaf type was the highest, and that of Haixiang 1 was the lowest. The soluble protein content ranged from 0.17 to 0.25 mg/g. Among them, the trunk soluble protein content of Haixiang 1 was the highest, and that of Piyou type was the lowest. The cellulose content ranged from 0.46 to 0.61 g/g. Among them, the trunk cellulose content of Haixiang 1 was the highest, and that of of Haixiang 2 was the lowest. The analysis results indicated that there were significant differences in pH, starch content, soluble sugar and cellulose content among different A. sinensis germplasms (P<0.05), but no significant differences in soluble protein content. There was a very significant negative correlation between pH and soluble sugar content, starch content (P<0.01). There was a very significant positive correlation between starch content and soluble sugar content (P<0.01). The content of soluble protein and cellulose content had no significant correlation with other physiological traits. This study could provide basic data for varieties breeding, upgrading and adjustment of planting industrial structure, DUS test guidelines and so on.

Salt damage is a common factor that hinders the normal growth of plants in agriculture. The southern end of Guangxi has a long coastline facing the South China Sea. Bananas are widely planted on the coastline. Seawater is often poured into the land, causing high concentrations of salt stress. Every year from August to September is the high-incidence period of typhoons. The water vapor formed from the South China Sea enters the inland with the typhoon, which will cause low-concentration salt stress. In this paper, taking Pisang Awak as the research material, the nutrient elements and soil components of each part of the Pisang Awak plant under salt stress were measured, the absorption and distribution characteristics of the elements were studied, and the mechanism of salt tolerance was analyzed. The results showed that: when the salt concentration of soil was 0.01%, the nutrient element content of each part was not significantly different from that of the control; when the salt concentration was greater than 0.01%, with the increase of the salt concentration, the total nitrogen, total phosphorus, total potassium, total magnesium and total calcium showed a decreasing trend, indicating that the higher concentration of salt stress reduced the ability of Pisang Awak to absorb nutrients from the soil, but the total magnesium and total calcium content of leaves decreased more slowly than those of other parts, and the proportion of the decline was lower. It was also lower than those of other parts, indicating that the leaves might have the ability to selectively absorb Ca²⁺ and Mg²⁺; when the salt concentration was greater than 0.01%, the Cl and Na contents of roots and pseudostems increased rapidly, and the increase speed and amplitude were much greater than those of leaves and bulbs. Therefore, it is believed that the mechanism of salt tolerance of Pisang Awak is that more Cl and Na were stored in the root and that Cl and Na were absorbed by the stem during the transportation to the leaves. When the salt concentration was greater than 0.2%, the contents of alkaline hydrolyzable nitrogen, available phosphorus and available potassium in the soil showed a decreasing trend, indicating that the high concentration of salt hindered the flow of mineral ions in the soil to the root surface. The research results could provide a data basis for the changes of elements in various parts of Guangxi Pisang Awak and the changes of soil components when they are subjected to seawater inversion and typhoon weather.

Based on the survey data in 2003 and 2019, the diversity of wetland vascular plants in Jianhu Provincial Nature Reserve in Yunnan was studied. The wetland plants were determined according to the standards issued by the State Forestry Administration and the division of relevant literatures. The results showed that there were 129 species of wetland vascular plants belonging to 83 genera and 34 families in Jianhu wetland, which could be divided into 12 distribution types and 12 forms. The temperate species accounted for 75.19% of the total number of wetland vascular plants in the reserve; There were 13 species endemic to China, accounting for 10.08% of the total number of wetland vascular plants in the reserve, including 4 species endemic to Yunnan, accounting for 3.10% of the total number of vascular plants in the wetland reserve. According to the classification and statistics of life forms, 92 species of hygrophytes, 19 species of submerged plants, 9 species of emergent plants, 5 species of floating plants and 4 species of floating leaf plants were obtained. The wetland vegetation consisted of 5 vegetation subtypes, hygrophyte type, emergent plant type, floating plant type, floating leaf plant type and submerged plant type, and 17 formations, for example, Polygonum hydropiper, Oenanthe javanica and Carexbolting sp. formation and Polygonum hydropiper, Polygonum amphibium and Polygonum strindbergii formation. According to the species habits, morphological characteristics, habitats and sources in the field investigation, it is determined that there were 4 categories and 63 species of secondary vascular plants in Jianhu wetland, and the floristic secondary degree was 48.84%. There were 39 species of wetland vascular plants in Jianhu Lake and Lashihai in Northwest Yunnan, with a species similarity of 22.29%, and 18 species of wetland vascular plants in Chenghai in Central Yunnan Province, with a species similarity of 10.00%, with a higher similarity with Lashihai. The results show that the vascular plants in Jianhu wetland are characterized by high species richness, significant temperate components, extremely low endemic rate, complete life forms, diverse community types, high floristic secondary degree and obvious components in Northwest Yunnan. The main reasons for the diversity of wetland vascular plants in Jianhu Lake are the high altitude, north latitude and serious human impact on Jianhu Lake, which are directly related to the characteristics of Jianhu Lake, such as shallow water, fast water replacement, low pollution, gentle lake bed inclination, large bank curvature and thick sludge at the bottom.

In order to clarify the difference of jasmonic acid (JA) synthesis and signal pathway genes expression in pepper before and after aphid feeding, the molecular mechanism of JA pathway-mediated resistance to aphid in pepper was preliminarily clarified based on the effects of aphid densities and infestation time. The aphid-resistant pepper variety ZDC and aphid-susceptible pepper variety DYJJ were used as the materials. The expression changes of JA synthesis pathway genes (LOX2, AOS, AOC and OPR3) and signal pathway genes (COI1 and JAR1) related to plant defense were analyzed by real-time quantitative PCR after aphid density (20, 30, 40, 50 and 60 aphids/leaf) and feeding time (6, 12, 24, 48 and 72 h). The results showed that under different aphid population densities and infestation time, the expression levels of the four genes in JA synthesis pathway in ZDC were generally significantly higher than those in DYJJ, while the expression levels of the two genes in signal pathway were generally significantly lower than those in DYJJ. Under the condition of low aphid damage level, there were significant differences in the expression levels between resistant and susceptible pepper varieties, and the peak and trough time of some gene expression were basically the same under the same aphid population density. Under high level of damage, the difference between resistant and susceptible pepper varieties decreased significantly. The above results showed that JA synthesis and signaling pathways AOS, AOC and JAR1 genes might have the potential to be used as molecular indicators for the identification and evaluation of aphid resistance in pepper, which could provide a theoretical basis for the evaluation and innovative utilization of aphid-resistant germplasm resources in pepper in the future.

In this study, 20 phenotypic traits of 81 Capsicum annuum germplasm resources were analyzed by genetic diversity, correlation, principal component analysis and cluster analysis. The result showed that the genetic diversity index (H´) of the 20 phenotypic traits was 5.91-6.32, Shannon-Wiener diversity index of leaf shape was the highest, and one quantitative trait had the coefficient of variation (CV) of 29.28%, indicating that rich genetic diversity in the phenotypic traits of 81 C. annuum germplasms. The correlation analysis indicated that there were 65 correlation coefficients between traits reaching significant or extremely significant level, indicating that most phenotypic traits influenced and promoted each other. The results of principal component analysis showed that the cumulative contribution rate of the first four principal components was 57.526%, and represented the main information of phenotypic traits of C. annuum, indicating that the four principal components could reflect the basic characteristics of 20 phenotypic traits. Based on the eigenvalue and contribution rate, fruit shape, fruit shoulder shape, leaf shape, nodal position of first flower, spicy taste, fruit color, cotyledon color, main stem color, anther color, hypocotyl color and style color were the main factors causing phenotypic differences of C. annuum germplasms. The cluster analysis results showed that the 81 C. annuum germplasms were divided into 5 groups at a genetic distance of 16.0 which effectively distinguished the germplasm of different genetic relationships. Group Ⅰ contained 21 germplasms that were C. chinense Jacquin, which had light green cotyledon, flat lantern fruit shape and extremely spicy taste. Group Ⅱ contained 38 germplasms which were mainly based on C. annuum var. lgrossum, and the main characteristics were no stem hair, medium branching, lantern fruit shaped and no spicy taste. Group Ⅲ contained 20 germplasms that were mainly based on C. annuum var. longum, which were mainly characterized by no shoulder shape, purple hypocotyl and spicy taste. Group Ⅳ and Group Ⅴ were composed of one germplasm, indicating that the two germplasm (L206 and L508) were far related to other germplasms and could be used for parental selection in C. annuum breeding. The research would provide an important reference for the utilization, innovation of C. annuum germplasm resources and variety breeding.

Simple sequence repeats (SSR) and single nucleotide polymorphism (SNP) markers have been confirmed to be high sensitivity and specificity. Development of molecular markers related to different types of fruit quality traits of Canarium album (Lour.) Raeusch. can provide reference for its molecular assisted breeding to a considerable extent. The fully mature fruits of C. album cv. Changying and Huiyuan were collected to use as materials. After total RNA extraction and cDNA library construction, the transcriptome was sequenced on the Illumina Novaseq platform, and the SSR, SNP and InDel loci characteristics of the transcriptome were analyzed by MISA 1.0 and GATK3 software. Results showed that a total of 13 935 SSR loci were identified from 10 124 unigenes of C. album fruit transcriptome, the average 1 kb sequence appeared 0.25 SSR loci, the frequency and average length was 22.98% and 14.34 bp, respectively. Among them, the single base repeat type had the largest number of SSR loci (accounting for 66.80%), with a length of 10-64 bp, and an average length of 12.85 bp, the repeat times of repeat motifs were concentrated in 9-12, and the motif with the highest frequency was A/T (accounting for 66.67%). The number of SSR loci of six base repeat motif type was the least (0.47%), the length was 30-54 bp, which average length was 31.76 bp, the number of motif repeats was concentrated in 5-8 times, and the motif with the highest frequency was AGATGG/ATCTCC (0.04%). A total of 284 992 SNP loci were detected in the transcriptome of C. album fruit, the average 1 kb sequence contained 5.21 SNP loci; Among them, the number of SNP loci of transformation type was 166 162, including C/T and A/G. The number of SNP loci of transversion type was 118 830, including A/T, A/C, T/G and C/G. In addition, 18 548 InDel loci were found in the transcriptome of C. album fruit, the average 1 kb sequence existed 2.95 InDel loci. The number of unigenes containing one InDel locus was the largest. It was predicted that the unigene containing the most InDel loci might be the callose synthase gene. These results showed that SSR and SNP/InDel markers could be effectively developed through RNA-seq. The SSR loci and SNP/InDel loci were widely distributed in C. album fruits with different quality traits. The results would provide a data basis for the development of identification markers of C. album fruit traits.

Zanthoxylum motuoense is a characteristic spice plant produced in Metok, Tibet, with high economic value and development potential, but the lack of seedlings is the main factor restricting its industrialization development. Therefore, it is very important to solve the problem of artificial breeding of Z. motuoense. As a common method to expand seedlings, the seed planting method has the advantages of high propagation coefficient, convenient operation and convenient transportation and storage, which is more conducive to the application of production practice. The seeds of Z. motuoense has dormancy characteristics, and it is difficult to germinate under natural seeding condition. Therefore, it is imperative to explore the dormancy characteristics, germination limiting factors and methods to break seed dormancy of Z. motuoense seeds to provide scientific basis for the production of Z. motuoense seedlings. Using Z. motuoense seeds as materials, the reasons of dormancy, dormancy types and methods to break dormancy were studied by water absorption and germination inhibitors, low temperature stratification, chemical immersion. The seed coat was thick, the outer layer was smooth oil layer, and the seed empty shell rate was 25.67%. The seed coat had obvious mechanical hindrance to the water absorption of seeds. Both the methanol extract from the intact seeds and seed coat of Z. motuoense had inhibitory effect on the germination of Brassica pekinensis seeds, and the inhibition degree of the methanol extract from the intact seeds was higher than that of the seed coat, indicating that the embryo and endosperm had germination inhibitors. Under appropriate temperature conditions, the combination of concentrated sulfuric acid + GA₃ could effectively break the dormancy of the seeds. Among them, the highest germination rate was 83.33% by soaking in concentrated sulfuric acid for 10 min + 1500 mg/L GA₃ soaking for 48 h + constant temperature culture at 30 ℃. Under the constant temperature of 30 ℃, the seed germination effect was better than that of 25 ℃ and 15 ℃/25 ℃. Conclusion: Water absorption barrier caused by seed coat and the endogenous inhibitors in the seeds are the main reasons for seed dormancy, and its dormancy type belongs to compound dormancy (PY+PD). Concentrated sulfuric acid treatment for 10 min + 1500 mg/L GA₃ soaking seeds for 48 h + 30 ℃ constant temperature culture can effectively break seed dormancy and improve seed germination rate.

The evaluation index system of heat resistance of Camellia gauchowensis Chang was studied to screen out varieties with strong heat resistance, and to provide theoretical basis for the breeding and cultivation of heat resistant varieties. Using six Camellia gauchowensis Chang clones as the test materials, 14 leaf morpholog, anatomical structure and leaf stoma related indexes were measured by image software analysis, paraffin section and nail polish blotting methods. Cluster analysis and correlation analysis were performed by SPSS software to screen out the main indicators related to heat resistance. The average membership function was calculated by EXCEL software for comprehensive evaluation of heat resistance and ranking. The leaves of C. gauchowensis Chang were composed of upper and lower epidermal cells, mesophyll tissue cells and leaf midribs. The leaf was ectopic leaves, the thickness of the upper epidermis was greater than that of the lower epidermis, the stomata was distributed in the lower epidermis, the palisade tissue was closely arranged 1-2 layers, and the spongy tissue was loosely arranged. leaf midribs were mainly composed of upper and lower epidermis and closely arranged vascular bundles. There were significant differences in leaf morphology and anatomical structure among the six clones (P<0.05). The 14 indicators were divided into four categories by systematic clustering. Leaf length, leaf width and leaf area were in the first category, leaf thickness, palisade tissue thickness, leaf structure compactness and palisade-sea ratio were in the second category, thickness of the upper epidermis, the thickness of the lower epidermis, leaf structure porosity, sponge tissue thickness and stomatal density were in the third category, and thickness of the leaf midrib and the thickness of the vascular bundle were in forth category. Leaf area, palisade tissue thickness, spongy tissue thickness and vascular bundle thickness were found to be the typical indicators of heat resistance of C. gauchowensis Chang by correlation coefficients analysis. The membership function formula was used to calculate the four typical indicators, and the comprehensive calculation and sorting were carried out according to the average membership degree. The heat resistance ranking of the six C. gauchowensis Chang clones was A16>A5>HMZ24>A11>HM19>HMZ25. The leaf indicators affecting the heat resistance of C. gauchowensis Chang are mainly leaf area, palisade tissue thickness, spongy tissue thickness and vascular bundle tissue thickness. There is a big difference in the analysis of a certain index, and the comprehensive comparative analysis through the membership function method can reflect the difference in heat resistance of Camellia gauchowensis Chang.

Phalaenopsis is the most popular Spring Festival pot flower in China. In order to accurately regulate the flowering stage and excavate the key flowering gene in the production and cultivation of Phalaenopsis, this paper studied the effects of growth regulators GA₃ and 6-BA on the flowering of Phalaenopsis Big Chilli, and the PhPIF4 gene selected from transcriptome data was cloned, and its bioinformatics analysis and response to growth regulator GA₃ were studied. The results showed that PhPIF4 had a typical conserved domain of the bHLH_SF super family (cl00081) homobox family. PhPIF4 of Big Chilli is closely related to Phalaenopsis equestris, followed by Cymbidium ensifolium, C, sinense and Dendrobium catenatum. The protein encoded by PhPIF4 was localized in non-chloroplast organelles. GA₃ treatment increased stalk length and the maximum stalk length of the treatment group was 200 mg/L GA₃. GA₃ could bring forward flowering 9-11 d. 6-BA significantly increased the number of flowers, and the treatment group with the most flowering amount was 300mg/L 6-BA, but 6-BA had no significant effect on flowering time and stalk length. When the two growth regulators were mixed to spray, the effect on flowering time and flowering time of Phalaenopsis was between the two. PhPIF4 was closely related to the development of flowering, and its expression gradually increased with the development of flowering. After spraying GA₃, the expression of PhPIF4 in flower buds, leaves and roots increased, and the increase was the largest in flower bud stage, suggesting that the expression of PhPIF4 might be affected and regulated by GA₃, and PhPIF4 might participate in the gibberellin flowering pathway. In this paper, the effects of GA₃ and 6-BA on reproductive growth of Phalaenopsis were studied, and the expression of PhPIF4 in response to GA was investigated, which would lay a foundation for revealing the role of PhPIF4 in gibberellin regulation of growth and development regulatory network.

Based on the investigation of communities, the community type, species composition, diversity, succession degree and diameter breast-high structure of alpine wetland from wet herbaceous to woody plant stage in alpine wetland of Mao'er Mountain, Guangxi and exploring the succession process and trends of plant communities were analyzed using the quadrat method. 136 vascular plant species, belonging to 103 genera and 62 families, were recorded in the survey area. The proportion of single family and single species was large. Simpson index was high and the species diversity was rich. It had important status and high research value in the alpine wetland of Mao'er Mountain. The geographical composition of species was complex, with transitional characteristics of tropical, subtropical and north temperate zones, which containing the endemic genera of Latouchea, Notoseris and Tsuga chinensis. Wetlands of T. chinensis was rare, and the wetlands in this area remained pristine, which had great conservation significance. It was a composite structure which including grass, scrub and tree layers. Flora was divided several different communities by calculating the importance values of the species. Plant species richness was not an accurate measure of community succession. The number of plant species generally increased and then decreased as succession progresses. And the maximum value occurred in the middle and late period of succession. It can be inferred that the succession sequence from wet herbaceous plant stage to woody plant stage is Juncus prismatocarpus grass→Carex nemostachys grass→Rubus caudifolius shrub→Acer sinense shrub→Fargesia nitida shrub→theropencedrymion of T. chinensis community→laurilignosa of Cyclobalanopsis stewardiana + Bennettiodendron leprosipes community→Mixed evergreen deciduous forest of Gamblea ciliata var. Evodiaefolia community. It was the forward succession under natural conditions. By analyzing the DBH structure of the dominant species in tree communities, the community succession was in process. T. chinensis community was large fluctuations, C. stewardiana and B. leprosipes was stable community, and there was a tendency of decline in population development of G. ciliata var. Evodiaefolia community. The end result of succession was formed a climax community. So it's still in the progress of succession in alpine wetland of Mao'er Mountain, the final stable forest community had not been formed so far.