The above-ground biomass (AGB) is an important indicator to reflect the productivity, carbon sequestration capacity, and carbon storage of rubber tree. However, the AGB models of individual rubber tree with high estimation efficiency and accuracy are still needed to develop. In the present study, an 8-year-old forest established for rubber tree breeding trial was scanned to obtain the point cloud data by using Unmanned Aerial Vehicle-Light Detecting and Ranging (UAV-LiDAR), meanwhile, the actual AGB of every tree in this forest was measured experimentally. Four individual tree structure parameters, such as tree height, crown width, crown projected are, and crown volume, were extracted from the point cloud data, and then, used as predictors to establish the individual rubber tree AGB model. The multiple nonlinear regression and random forest regression were both applied to establish the model, and the estimation accuracy, generalization ability and reliability were evaluated by five-fold cross-validation. The tree height and crown width values extracted by special algorithms from individual tree point clouds data were highly correlated with the values manually measured on point clouds, the Pearson correlation coefficients of the two parameter wase 0.999 and 0.951 respectively, and the root mean square errors (RMSE) was 0.109 m and 0.452 m respectively. The correlations between the four structure parameters and the AGB of individual rubber tree was significant. Especially, the parameter of crown volume had the highest Pearson correlation coefficient (0.904). All four parameters had good explanations for AGB. Both established AGB models based on the four individual tree structure parameters could achieve good fitting results. However, the method of random forest regression had a better performance compared with multiple nonlinear regression. The coefficient of determination (R²) of the random forest regression model was 3.64% higher than that of the multiple nonlinear regression model, and the relative root mean square error (rRMSE) of the random forest regression model was 2.66% lower than that of the multiple nonlinear regression model. In general, there is higher goodness of fit and stronger generalization ability of the random forest regression model which can more accurately estimate the rubber tree AGB.

In order to select urban greening plants with excellent dust retaining capability, seven species of shrubs, including Allamanda cathartica, Duranta erecta 'Golden Leaves', Ficus microcarpa 'Golden Leaves', Hibiscus rosa-sinensis, Ixora chinensis, Pittosporum pentandrum var. formosanum and Heptapleurum arboricola, growing in the road green belt of University Road in Nanning, were studied to observe the leaf morphology and the ultrastructure characteristics of leaf epidermis, and collected and measured the dust retaining capability per unit leaf area at the same time. The results revealed that the plant leaves had more dust retaining in winter than in summer in this section of the road studied, and that dust particles greater than PM₁₀ were accumulated more than PM₁₀ or PM_2.5. Among the species studied, D. erecta GL had the most outstanding ability of dust retaining, I. chinensis and H. rosa-sinensis were more dust retaining capability with particle diameters more than PM₁₀, while F. microcarpa GL and P. pentandrum var. formosanum had more clear advantage in dust retaining with fine particles such as PM₁₀ and PM_2.5. According quantified principal component analysis, the five characteristic including: whether the leaf blade was hairy or not, leaf margin type, the number of primary lateral veins, the netting status of the terminal lateral veins and the distribution status of the leaf veins on the leaf surface contained most of the information on the relationship between leaf morphological traits and dust retaining capability. Among the ultrastructure features of the leaf epidermis, projecting anticlinal wall of the upper epidermal cell and granular ornamentation of waxy layer contributed to stronger dust retaining than flocculent ornamentation of waxy layer. Striped ornamentation of cuticle that was too thick or too thin and neatly arranged were not benefit to dust retaining. And the cuticle of the outer edge of stomatal outer arch of the lower epidermis of the leaf had a multilayered ring structure which facilitating the adhesion of more dust particles. The findings of this study could help to provide a reference for the selection of plants for greening and air purification in different types of atmospheric pollution environments and give us a theoretical basis for the study of plant dust retaining. In the strategy of dust retaining, seven plants showed some differences in the macro-morphological characteristics of leaves and ultrastructure of epidermis. D. erecta GL had the largest dust retaining capability, various leaf colors and outstanding landscape effects, so it is worth popularizing. In the dust environment dominated by large particulate matter, I. chinensis and H. rosa-sinensis are recommended, while in the environment with fine dust particles, F. microcarpa GL and P. pentandrum var. formosanum can be planted more.

The constituents of the fruiting body of Fuscoporia punctata (Fr.) Cunn were isolated and purified by different column chromatography and HPLC method to study the the pharmacological basis, chemical constituents and biological activity. The structures of the compounds were identified by spectral data analysis including-NMR and MS. The inhibitory activity of α-glucosidase and protein tyrosine phosphatase 1B (PTP1B) for the compounds were evaluated by PNPG and pNPP methods, respectively. The DPPH scavenging activity of the compounds was determined by the DPPH method. The results preliminarily identified the main chemical composition types of F. punctata (Fr.) Cunn. 12 compounds, including 7 polyketides, were isolated from the EtOH extract of the fruiting body of F. punctata and were identified as inoscavin A (1), inoscavin C (2), phellibaumin A (3), phellibaumin D (4), inonotusin B (5), phellifuropyranone A (6), phelligridin D (7), protocatechualdehyde (8), catechol (9), pyrogallol (10), p-hydroxybenzoic acid (11), and 4-hydroxybenzylideneacetone (12). Compounds 4, 5 and 7 had definite PTP1B inhibitory activity with the IC₅₀ values of (60.83±2.01), (56.33±1.57), (66.89±0.96) μmol/L, respectively. Compounds 2 and 7 exhibited inhibitory activity againstα-glucosidase with the IC₅₀ values of (127.77±0.56), (122.99±1.39) μmol/L, respectively. The IC₅₀ value of compounds 4, 7, 2 and 6 scavenging DPPH radical was (6.71±0.69), (25.79±1.59), (30.45±1.67), (32.90±1.59) μmol/L, respectively. All the compounds were obtained from these fungi for the first time. Most of the polyketides had PTP1B inhibitory activity, α-glycosidase inhibitory activity and DPPH scavenging activity, which would provide theoretical basis for the further development and utilization of F. punctata (Fr.) Cunn.

This paper aimed to clarify the effect of different microbial agents on pepper blight and the influence of rhizosphere soil bacterial community structure, and to provide a green prevention technical basis for reducing the occurrence of pepper blight. Six microbial agents, including Bacillus subtilis, Trichoderma harzianum, Pseudomonas fluorescens and Streptomyces enissocaesllis were selected as the main research objects to study the effects on the control of pepper blight and the bacterial community structure in rhizosphere soil under pot experiment by high-throughput sequencing. A₁ (1×10⁸ CFU/g of B. subtilis microcapsule) and A₂ (1×10⁸ CFU/g of T. harzianum water-dispersed granule) had the best control effect, and the control effect was 85.58% and 81.97%, respectively, and others the control effects of A₃ (5×10⁸ CFU/g Pseudomonas fluorescence granules). The best control effect of A₄ (4×10⁹ CFU/g S. enissocaesllis NBF715 powder), A₅ (1×10¹⁰ CFU/g B. subtilis wettable powder), A₆ (3×10⁸ CFU/g T. harzianum wettable powder) and A₇ (50% carbendazim wettable powder) was 47.17%, 49.12%, 30.60%, 39.86%, 25.83%, respectively. Based on the high-throughput sequencing analysis, the bacterial community composition of pepper rhizosphere soil at phylum level, different microbial agents increased the proportion of Proteobacteria and Bacteroidota, especially A₁ and A₂ significantly increased the richness of Proteobacteria and Bacteroidetes. At the family level, the richness of Chitinophagaceae, Steroidobacteriaceae and Micrococcaceaee were improved by microbial agent treatment, and significant difference was found between A₁ and A₂ treatments. The total number of bacterial OTUs and the number of unique bacterial OTUs in the rhizosphere soil of Capsicum treated with A₁, A₂, A₇, A₈ (treatment of inoculated P. capsici) and CK (water) were analyzed by Venn diagram. The total number of bacterial OTUs and the number of unique dominant bacteria in the rhizosphere soil of capsicum increased in the A₁ and A₂ treatments, while the richness and diversity of soil bacteria decreased in the A₇ treatment. In conclusion, the control effect of A₁ and A₂ on pepper blight was more than 80%, and the richness and diversity of unique dominant bacteria in the rhizosphere soil of pepper increased, and the ability of pepper to resist P. capsici infection was enhanced. A₁ and A₂ could be used as agents to control pepper Phytophthora blight. At the same time, the use of carbendazim reduced the richness and diversity of soil bacteria, and the pathogen could invade the root of pepper more quickly after the reduction of microbial diversity.

In this experiment, Pandanus amaryllifolius Roxb. plantlets in vitro were used as detected material. In order to investigate the most suitable fertilization formula for increasing aroma of P. amaryllifolius Roxb. plantlets in vitro. And the volatile components of P. amaryllifolius Roxb. plantlets in vitro were separated and identified by gas chromatography-mass spectrometry (GC-MS), and the results were analyzed by principal component analysis (PCA) and cluster heatmap analysis. The results showed that the volatile components were similar in seven different treatments, but their volatile contents were different greatly (P<0.05). A total of 21 volatile components were detected, including alcohols, pyrroles, esters, ketones, furans, furans, acids, olefins and phenols, and squalene, phytol. Among them 2-acetyl-1-pyrroline (2AP), neophytadiene, 3-methyl-2-(5H)-furanone, 2,3-dihydrobenzofuran were the main volatile components. The average content of the characteristic aroma component 2AP were (48.07±13.14)μg/g of P. amaryllifolius Roxb. plantlets in vitro, and the treatment 6 (zinc+fertilizer combinations) was hightest to 72.03 μg/g; however the treatment 1 (IBA+zinc+fertilizer combinations) was the lowest to 31.96 μg/g, and the treatment 6 could significantly increase the content of the characteristic aroma component 2AP. The results of principal component analysis showed significant difference between the fertilizer combinations treatment (ammonium bicarbonate + calcium superphosphate+potassium chloride) and the water treatment, and the main volatile components of the treatment 2 and the treatment 6 were phytol, 2AP, 3-methyl-2-(5H)-furanone, 2,3-dihydrobenzofuran, neophytadiene; and the main volatile components of the treatment 1 and the treatment 5 were ethyl oleate-based esters, 2,4-di-tert-butylphenol-based phenols, acetol-based ketones. The volatile components were mainly squalene in the treatment 3, treatment 4 and treatment 7. Cluster analysis showed that higher volatile component in the treatment 6 (zinc+fertilizer combinations), and the volatile component were significantly lower in the treatment 1 (IBA+zinc+fertilizer combinations). There were no obviously differences in other treated groups. The conclusion indicated that zinc sulfate immersion and ammonium bicarbonate+calcium superphosphate+potassium chloride fertilizer can improve aroma than other groups.

The fungal secretory expression vector p74HSP-EGFP constructed in a previous study can express the target gene in fungal pathogens and secrete the target protein into plants during fungal infection and colonization, thus verifying the function of the target gene. However, the promoter of toxin A gene (ToxA) driving the target gene in p74HSP-EGFP is not a endogenous promoter of Fusarium oxysporum f.sp. cubense (Foc). For more efficient expression of target genes in Foc, the promoter of secreted in xylem 1d (Six1d), which is highly expressed in Foc, was cloned using the genomic DNA of Foc race 1 (Foc1) as a template, replacing the ToxA promoter in p74HSP-EGFP, and the newly constructed fungal secretory vector was named pSix1d74HSPG. Foc tropical race 4 (Foc TR4) was transformed by p74HSP-EGFP and pSix1d74HSPG. The transformed strains were cultured in potassium salt liquid medium (KK) containing 100 μg/ml hygromycin for 5 days, respectively. The fluorescence intensity and the abundance of EGFP protein secreted outside the cell were detected. The results showed that the expression intensity of EGFP driven by Six1d promoter in pSix1d74HSPG was 1.6-1.7 times of that driven by ToxA promoter in p74HSP-EGFP, which could replace the p74HSP-EGFP vector for more efficient expression and secretion of target proteins in Foc for functional characterization. Our work provides an important experimental tool for the study of the molecular mechanism of resistance and susceptibility to banana fusarium wilt.

Paphiopedilum venustum, an endangered wild resources, has high ornamental value and conservation biological value. Chloroplast genome (cpDNA), small with stable structure and high conserved in nature, has been widely used in plant phylogeny and species identification. Understanding the chloroplast genome structure of P. venustum is of great significance in revealing the phylogenetic relationship of Paphiopedilum. In this study, the whole chloroplast genome of P. venustum was sequenced by the Illumina sequencing technology, the chloroplast genome was annotated using GeSeq, BLAST and hmmer, the genome structure, gene number, repeats, codon usage bias, phylogenetic development were analyzed using the bioinformatics softwares such as MISA, codonW and Fasttree. The chloroplast genome of P. venustum had a conserved quadripartite structure, with a pair of inverted repeats (IRs) separated a large single copy (LSC) region and a small single copy (SSC) region from the small single-copy region (SSC), with a total length of 158 298 bp. The guanine and cytosine (GC) content of chloroplast protein coding genes was 35.4%, and 129 genes were annotated, including 79 protein coding genes, 38 tRNA genes, 8 rRNA genes, and 4 pseudogenes. 78 simple sequence repeat (SSR) loci were detected, most of which were mononucleotide repeats and dinucleotide repeats, accounting for 84.62% and 10.26% respectively. There were no pentanucleotide repeats, and most of the repeats were composed of A or T base. 32 high-frequency codons were identified, and 90.6% of them ended in A or U, preferred codons ending in A or U. The codon encoding leucine (Leu) had the highest frequency of use, while the codon encoding cysteine (Cys) had the lowest frequency of use. Phylogenetic tree was constructed by comparing the chloroplast genomes of 18 orchidaceae plants. It was found that the two species of Cypripedilum calceolus and C. tibeticum were separated from 16 species of Paphiopedilum and clustered into a single branch, and the genus of Paphiopedilum was divided into two groups, among which P. venustum and P. purpuratum were closely related. SSR and nucleotide polymorphisms can be used as molecular markers for germplasm identification and genetic diversity analysis of Paphiopedilum, which could provide a theoretical basis for germplasm identification and phylogeny of rare and endangered plant Paphiopedilum and its relatives, and lay a foundation for population restoration, biodiversity protection, innovative utilization and new variety breeding of Paphiopedilum.

Chinese cabbage Sclerotinia rot is caused by Sclerotinia sclerotiorum, which seriously endangers the yield and quality of Chinese cabbage. In this study, the transcription level of resistance genes to the infection of S. sclerotiorum were explored at the molecular level and provided candidate genes for further study of disease resistance mechanism. The leaves of resistant inbred line H72 and susceptible strain Y26 were inoculated for transcriptome sequencing analysis. The results show that a total of 121.77 Gb clean reads were obtained by transcriptome sequencing analysis. Filtering the raw sequencing data, the clean reads of each sample were over 6 Gb, Q₂₀ ranged from 97.21% to 97.99%, and the average percentage was 97.61%, Q₃₀ ranged from 92.59% to 93.98%%, and the average percentage was 93.20%, indicating that the sequencing quality could be used for subsequent analysis. The number of common differentially expressed genes were 13 and 11 after inoculation for 36 h and 48 h, respectively. After removing the common differentially expressed genes at each time point, we obtained 18 differentially expressed genes. Combined with gene function annotation, 11 genes involved in defense response. MYB34 transcription factor was up-regulated, while ERF003 was down-regulated, which might negatively regulate the infection of S. sclerotiorum. Gretchen hagen 3.3 (GH3.3), PR proteins (TLP1), F-box, amino acid transporter (ANT1), caffeoyl-CoA O-methyltransferase (Cco AOMT), aspartyl protease (AED3), chaperone protein (DnaJ 11) were up-regulated, which were proposed to response to Chinese cabbage pathogen. The expression of epithiospecifier protein (ESP) and calcineurin B-like protein gene (CBL1) were down-regulated, and the disease resistance function in Chinese cabbage needs further analysis and verification. A further qPCR analysis was used to verify the transcriptome, The expression trends of differentially expressed genes ERF003, CBL1, GH3.3, MYB34, ANT1, TLP1 were consistent with that of transcriptome sequencing. These results will be helpful for further research the resistance mechanism to S. sclerotiorum.

Polyploidy can be accompanied by some super character, such as enhanced stress resistance, larger organ size, and increasing biomass. Polyploidy provides an important way for cassava varieties breeding. The single-node axillary buds of cassava variety SC12 were used as the explants to observe the effect of the different colchicine concentrations on autotetraploid induction rate. The morphology, anatomy and agronomic characteristics of autotetraploid and the diploid parents were compared. The highest efficiency of inducing autotetraploid of SC12 was 7.78% at the concentration of 0.03 g/L colchicine. The ploidy of 20 plants was identified by the flow cytometry and chromosome numbers counts in root tip cells. Consequently, a total of 11 tetraploid plants as well as 5 chimeric plants were obtained. Positive autotetraploid cassava lines accounted for 55% of all the tested lines, and the variation rate was 80% of the tested lines. Significant differences in morphology and anatomy were observed between the autotetraploid and the diploid parents. In morphology, the tetraploid plants became shorter, the stem became thicker, the leaf tip became shield, the leaves changed from lanceolate to arch, the cleft leaf length/cleft width decreased significantly, and the chlorophyll content increased significantly. The length, width and chloroplast number of tetraploid guard cells was significantly increased by 2.33%, 28.99% and 117.79%, respectively, compared with that of diploid parent. Stomatal density was decreased by 40.06% compared with the control. The guard cells of tetraploid variant were oval, while those of diploid variant were cylindrical. The leaf thickness and palisade tissue thickness of tetraploids were significantly higher than those of diploids, and increased by 24.41% and 43.88% compared with the control, respectively. The palisade tissue/sponge tissues of autotetraploid plants were 1.9 times as large as the diploid line, indicating that the palisade tissue of tetraploid leaves was closely arranged, but the spongy tissue was not well developed. The results of yield detection showed that the tubers weight per plant and harvest index of polyploid line SC12-11 was 3.30 kg and 0.43, respectively, which was significantly higher than that of the control.

Areca palm yellow leaf (AYL) disease caused by phytoplasma is a devastating disease of areca palm plantation. It is of great significance to clarify the genetic variation of phytoplasmas and the natural hosts in the garden of areca with yellow leaf diseases for the purpose of fully reveal the circulation path and epidemic law of the disease. In this study, the plant samples showing typical disease symptoms associated with phytoplasma were investigated and sampled from the diseased areca garden distributed in different areas of Hainan provinve, China. The target sequences of phytoplasma were amplified and sequenced with universal primers, revealing genetic variation and phylogeny of the phytoplasma. The results showed that 16S rRNA and secA gene fragments specific for phytoplasma was amplified from six plant sample of Trema tomentosa, which were all identical. The 16S rRNA gene fragment of phytoplasma was obtained from one plant sample of Chinaberry. Sequence analysis based on the 16S rRNA gene sequences indicated that the T. tomentosa witches'-broom phytoplasma (TtWB) strains identified in the study were in 100% similarity with TtWB phytoplasma reported previously. Chinaberry witches'-broom (CWB) phytoplasma strains identified in the study were in 100% similarity with CWB phytoplasma strains reported previously. Phylogenetic analysis indicated that TtWB phyto plasma strains identified in the study were clustered into one evolutionary branch with the phytoplasmas belonging to 16SrⅩⅩⅩⅡ group, CWB phytoplasma strain identified in the study were clustered into one evolutionary branch with the phytoplasmas belonging to 16SrⅠ group. 16S rDNA sequence similarity of phytoplasma was 100% among the strains of CWB and AYL. It is perfectly important for effective prevention and control of areca palm yellow leaf disease to timely clean up the natural hosts of phytoplasma such as chinaberry in areca diseased garden, eliminating the infection source and cutting off the transmission routes of the phytoplasma.