In order to clarify the effects of tropical organic materials on the physicochemical properties and microbial community structure of latosol, pineapple leaves, banana stems, coconut husk and organic fertilizer were selected as the test materials in this study and carried out organic materials-soil mixture incubation experiment with 90-day. After that, the effects of organic materials on soil pH, available phosphorus, aggregate, microbial community structure change and enzyme activity were compared with those of CK. The results showed that banana stems and organic fertilizer could increase soil pH value and available phosphorus content, and pineapple leaf aggravated soil acidification in the short term. Pineapple leaves and banana stems were helpful to promoting the formation of diameter > 0.25 mm aggregates. Pineapple leaves, banana stems and organic fertilizer increased the activities of soil xylanase, cellulase and leucine aminopeptidase, as well as the G⁺ strains, G^- strains, eukaryotes and fungi in soil. The average proportion of G⁺ strains in banana stems and pineapple leaves was 27.8% higher than that in CK (21.4%). Compared with CK, the proportion of fungi in banana stalk, pineapple leaf, coconut bran and organic fertilizer increased by 300.2%, 232.1%, 165.0% and 51.9%, respectively. The application of organic fertilizer significantly increased the proportion of AM fungi, while pineapple leaves and banana stems helped to increase the number of eukaryotic organisms in soil.

Erigeron annuus, a member of the Asteraceae family, is widely distributed in tropic, subtropical and temperate regions of China. It is a plant native to North America, which was introduced to China at the end of the nineteenth century as an ornamental plant. E. annuus has great medicinal value. Its whole plant has been used in folk medicine for the treatment of indigestion, enteritis, epidemic hepatitis, lymphadenitis, hematuria, acute inflammation, malaria and obesity. E. annuus could be a phytoremediator for metal- and metalloid-contaminated soils. It can degrade diesel effectively, has strong tolerance and accumulation for uranium, cadmium, zinc, lead, and antimony, and can be distributed in soils with high pollution levels. Hence, In this study, it was to explore the characteristics of chloroplast (cp) genome and its phylogenetic relationship, laying a foundation for the further development of species identification, control and full utilization of E. annuus. The complete cp genome of E. annuus was assembled and sequenced by Illumina Nova Seq 6000 Sequencing platform and SPAdes v3.10. software. Taking the cp genome of E. canadensis (MT806101.1) as a reference, the genome feature and phylogenetic analysis study were investigated. The cp genome of E. annuus was a circular and quadripartite structure with a total length of 153 283 bp. The GC and AT content of the cp genome was 36.77%and 63.23%, respectively. The cp genome of E. annuus had four typical regions, containing a pair of inverted repeats (IRs, 25 019 bp) that were separated by the large single-copy (LSC, 84 833 bp) and small single-copy (SSC, 18 412 bp). In total, 132 genes were predicted, consisting of 88 protein-coding genes, 36 transfer RNA genes, and 8 ribosomal RNA genes. The genes were divided into 4 categories according to the functions, including 45 photosynthesis genes, 73 self-replication genes, 6 other genes and 8 genes of unknown function. SSR site analysis revealed that the cp genome sequence contained 200 SSR loci in total, which were spaced disproportionately through the genome with the largest number of SSRs distributed in the LSC region, followed by the SSC and IR regions. LSC, SSC and IR regions had 126, 40, and 34 SSRs, respectively. The number of SSRs in LSC, SSC and IR regions was accounted with 63%, 20% and 17%, respectively. The SSRs were mononucleotides, especially for A/T. The second most abundant motif type was the trinucleotide type, especially TAA, TAT and TTA. Phylogenetic analysis showed that E. annuus was closely related to the plant of E. canadensis. This study revealed the cp genomic information of E. annuus and would provide essential data for further studies on genetics, phylogeny, utilization and prevention of this species. This study revealed the chloroplast genome information and identified the phylogenetic branches of E. annuus, which would provide molecular theoretical support for further research on population genetics, phylogenetic geography, adaptive mechanism and management of E. annuus.

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.

It is normally difficult to distinguish germplasms of Kadsura coccinea with morphological traits before they bear fruits because the evaluations on the specificity are mainly based on fruit and economic traits. Establishing DNA fingerprinting profile is useful for rapid and accurate identification of K. Coccinea germplasms. SSR analysis for 20 clones of K. coccinea was conducted using 15 pairs of primers, the clones were clustered based on Nei's (1972) genetic distance by UPGMA clustering method, and SSR fingerprinting profile was established through combinations of some markers. 15 pairs of primers produced 75 alleles at 15 loci from 20 clones of K. coccinea, with two to 15 alleles per locus, the Shannon diversity index varied from 0.199 to 2.456, polymorphic information index from 0.095 to 0.894, and genetic similarity coefficient from 0.328 to 0.891. The 20 clones could be divided into two groups by the UPGMA clustering method. All the 15 loci could not distinguish 20 clones separately, among which KCZ023 showed the strongest ability to distinguish. Two-loci combinations of KCZ023 with KCZ135, KCZ100 or KCZ147 as well as 28 three-loci combinations could distinguish all the 20 clones separately. The 20 clones of K. coccinea show abundant genetic diversity, and can be fully distinguished by any of three two-loci combinations or 28 three-loci combinations. The findings would provide evidences for germplasm identification and hybrid parent selection.

In order to research the biological characteristics of the pathogen and fungicide screening for Sedum morganianum of Corynespora cassiicola, the effects of temperature, pH, light condition and different carbon and nitrogen sources on mycelial growth were studied with the mycelial growth rate method, and the toxicity measurement of six fungicides to C. cassiicola was determined. The results showed that the optimum temperature for the mycelial growth of the pathogen was 30 ℃, the optimum pH for mycelial growth was 7, light was conducive to mycelial growth, the optimum carbon was glucose and nitrogen source was peptone. Toxicity measurement results showed that the six fungicides had different toxicity on the pathogen of C. cassiicola. Among them, the toxicity of mefentrifluconazole was the best, with EC₅₀ 0.0129 mg/L, followed prochloraz, with EC₅₀ 0.0135 mg/L. The toxicity of difenoconazole and fludioxonil were strong, with EC₅₀ 0.0273 mg/L and 0.0296 mg/L respectively. The toxicity of pyraclostrobin was mild, with EC₅0 0.0768 mg/L. The toxicity of carbendazim was the weakest, with EC₅₀ 0.9353 mg/L. The study could provide a theoretical basis and guidance for the cultivation of succulent plants and the comprehensive management of black rot.

Lagerstroemia speciosa Zichan is a new variety of Lagerstroemia speciosa. In order to provide theoretical basis for its cultivation and promotion application, the physiological characteristics would been explored. The paper used the Li-6400 XT photosynthetic apparatus to determine the light response curves, diurnal variation and chlorophyll of biennale L. speciosa Zichan and L. speciosa sapling. The results showed that: (1) The contents of chlorophyll a (Chla), chlorophyll b (Chlb), carotenoid (Car), chlorophyll content (Chl) and chlorophyll a/b (Chla/Chlb) of L. speciosa Zichan were higher than those of L. speciosa, and there were significant differences in the above indexes. (2) Diurnal change of photosynthetic rate of L. speciosa Zichan displayed a unimodal curve, and the peak appeared at around 10:00 am, which was 17.11 μmol/(m²·s); diurnal change of stomatal conductance and transpiration rate showed unimodal curves as well. The diurnal variation of intercellular CO₂ concentration was high in the morning and evening, low at noon, and the diurnal variation of stomatal limitation value was low in the morning and evening, high at noon. (3) Diurnal change of photosynthetic rate of L. speciosa displayed a bimodal curve, and the peak appeared at around 8:00 am or 12:00 am, which was 14.41 μmol/(m²·s) and 13.16 μmol/(m²·s); diurnal change of stomatal conductance showed bimodal curve as well, and the peak appeared at around 8:00 am or 12:00 am. The diurnal variation of transpiration rate showed unimodal curve, and the peak appeared at around 10:00 am. The diurnal variation of intercellular CO₂ concentration was high in the morning and evening, low at noon, and the diurnal variation of stomatal limitation value was low in the morning and evening, high at noon. (4)Grey relational analysis showed that the order of correlation degree between P_n and environmental factors of the two materials was PAR>C_a>RH. The order of correlation between P_n and physiological factors was T_r>G_s>T_a>C_i, while G_s>T_r>T_a>C_i. (5) The light saturation point of L. speciosa Zichan was 2388.729 μmol/(m²·s) and the light compensate point was 55.590 μmol/(m²·s); The light saturation point of L. speciosa was 2080.597 μmol/(m²·s) and the light compensate point was 29.871 μmol/(m²·s). Compared with L. speciosa and L. indica, L. speciosa Zichan showed the strong photosynthetic assimilation ability, but its adaptability to low light environment was weak. L. speciosa Zichan needs plenty of light, which is suitable for planting in the region with abundant light supply.

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.

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.

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.

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.