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.

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.

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.

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.

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.

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.

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.

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.

The effects of mixed silage of Stylosanthes Guianensis Reyan No. 2 and Pennisetum purpureum × P. glaucum cv. Reyan No. 4 on fermentation quality and nutrient composition were studied to screen out the appropriate proportion of mixed silage, and provide theoretical basis for the preparation of high-quality silage. The experiment was divided into 4 groups. The mixed silage ratios of Reyan No. 4 and Reyan No. 2 were 100∶0 (CK), 85∶15 (A₁), 70∶30 (A₂) and 55∶45 (A₃), respectively. Ensilage was unsealed for 30 days and sampled for detection. A₂ had the best sensory evaluation. With the increase of the ratio of Reyan No. 2, pH and NH₃-N/TN values gradually increased, and there were significant differences between A₁, A₂, A₃ and CK (P<0.05). The lactic acid (LA) content of A₃ was significantly lower than that of CK (P<0.05). The lactic acid/acetic acid (LA/AA) value was greater than 2.6 in all experimental groups. Butyric acid (BA) in A₂ was significantly lower than that in other groups (P<0.05). With the proportion of Reyan No.2 increasing, the content of crude protein (CP), dry matter (DM) and ether extract (EE) in all groups increased, and were significantly higher than those of CK (P<0.05). Water-soluble carbohydrate (WSC) content showed an increasing trend, and there was no significant difference among groups (P>0.05). Neutral detergent fiber (NDF) decreased gradually, and there was no significant difference among all groups (P>0.05). Acid detergent fiber (ADF) in all groups was significantly decreased (P<0.05). The ash content of each group decreased, and there was no significant difference among A₁, A₂ and A₃ compared with CK (P>0.05). In conclusion, the mixed silage of Reyan No. 2 and Reyan No. 4 can improve the fermentation quality and nutritional value of silage. Considering the fermentation quality and nutritional value, it is suggested that A₂ is suitable for silage.