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.

Southwest Guizhou Autonomous Prefecture is a typical mountainous area with low latitude and high altitude and has abundant water resources. The specific climate and geographical environment of this region enables the appearance of abundant wild sugarcane germplasm resources. In order to enrich the wild germplasm resources and genetic diversity of National Germplasm Repository of Sugarcane (NGRS), and reveal the distribution of wild sugarcane germplasm resources in the region, the wild sugarcane resource investigation team of Sugarcane Research Institute of Yunnan Academy of Agricultural Sciences conducted a survey and collection for 14 days in 4 cities of the region from May 9 to May 22, 2020. Four cities, Xingyi, Xingren, Qinglong and Pu'an, were selected as the main collection areas, and a total of 92 wild sugarcane resources were collected. We collected 6 materials of Erianthus rockii, 16 of Sacchuram spontaneum, 25 of Micanthus sinensis, 13 of Erianthus arundinacius and 32 of Erianthus fulvus. The results revealed that there were abundant phenotypic variation in the species collected from this region with variation coefficient ranging from 11.4% to 78.0% and the average over 30%. Cluster analysis showed that Sacchuram spontaneum group Ⅲ (Sp-2), Micanthus sinensis Group Ⅱ (Ma-8), Erianthus arundinacius Group Ⅲ (Ea-2, Ea-9), Erianthus fulvus Group Ⅲ (Ef-10, Ef-11), Erianthus fulvus Group Ⅴ (Ef-26) and Erianthus rockii (Er-1, Er-3, Er-4) had good yield and quality characters, and were recommended to be used as sugarcane breeding materials in further research. The germplasm collections changed the situation of CNNSGR collection system without collections from southwest Guizhou Autonomous Prefecture, and some specific materials had unique excellent characters that other wild sugarcane resources did not have, which might serve as the genetic resources for sugarcane breeding.

In this study, four stabilizers including potassium hydroxide (KOH), ammonia, sodium dodecyl sulfate (SDS) and potassium laurate were added to concentrated natural rubber latex (CNRL). The performance of the CNRL film was most affected by the amount of KOH. With the increase of KOH content, the Mooney viscosity of the film increased and the shrinkage rate decreased. The tensile strength, tensile stress, elongation at break, tear strength and hardness all decreased rapidly. With the increase dosage of potassium laurate, the Mooney viscosity and the shrinkage rate of the raw rubber film decreased to a certain extent. The tensile strength had a tendency to increase first and then decrease. With the increase of ammonia consumption, there was also a trend of first rising and then falling. More dosage of sodium dodecyl sulfate (SDS) would lead to lower tear strength of the raw rubber film. The performance of the vulcanizate film was also most affected by the amount of KOH. With the increase of KOH dosage, the M_L and M_H of the vulcanizate film would increase. The t₁₀, t₅₀ and t₉₀ would be shortened, and the film shrinkage was reduced. In addition, the tensile strength and elongation at break of the rubber film decreased. The tensile stress and tear strength had a trend of increasing first and then decreasing. As the amount of ammonia increased, the t₉₀ of the vulcanizate film would increase. The shrinkage rate of the film increasesd, and the tensile stress first increased and then decreased. With the increase of the amount of SDS, the t₉₀ of the vulcanizate film would be prolonged and the film shrinkage was reduced. With the increase of potassium laurate dosage, the M_L and M_H of the vulcanizate film would increase, the film shrinkage was reduced, and the tear strength showed a trend of increasing first and then decreasing. It could be seen from the hardness change that the film would become soft after adding KOH and the hardness would be greatly reduced. The Mooney viscosity of the film was greatly improved. After the addition of potassium laurate, the Mooney viscosity of the film decreased significantly, but the hardness of the film did not change much. From the perspective of vulcanization, after adding KOH, the vulcanization degree of the rubber film increased, and the vulcanization time decreased. KOH had a certain promotion and promotion effect on the vulcanization degree of the film. However, combined with the mechanical properties of the vulcanized film. The tensile stress of the film increased after adding KOH, but the tensile strength, tear strength and elongation were significantly reduced. However, the film strength changed little when the other three stabilizers were added.

Cassava (Manihot esculenta Crantz) is an important food crop in tropical and subtropical areas. SWEETs participate in a variety of plant activities, including sugar transport, reproduction and development, plant stress, and interaction with pathogens, which play an important role in plant development. In order to clarify the function of SWEET in the growth and development of cassava, sugar transporter MeSWEET18 was cloned from Cassava South China 9 (SC9) for bioinformatics analysis and verified sugar transport capacity by yeast experiment in this study. The expression trend of MeSWEET18 in cassava in different organ, different developmental stages and under abiotic stress were determined via qRT-PCR method. MeSWEET18 contained a 714 bp open reading frame (ORF) encoding a protein of 237 amino acids residues with predicted molecular mass of 25.94 kDa and theoretical isoelectric point of 6.57. Through instability index (II) analysis by ProtParam, the instability index (II) of the protein encoded by MeSWEET18 was 37.50, indicating the protein of MeSWEET18 as stable. MeSWEET18 was a typical membrane protein with a conserved domain MtN3_slv at the N-terminal and a PQ-Loop Super family conserved domain at the C-terminal and seven transmembrane domains. ProtScale predicted that MeSWEET18 was a hydrophilic protein. Phylogenetic tree analysis revealed that MeSWEET18 belonged to Clade IV. MeSWEET18 was in the same evolutionary tree as AtSWEET16 and AtSWEET17. Alignment of amino acid sequences revealed 53.23% homology between MeSWEET18 and AtSWEET16, and 56.05%homology between MeSWEET18 and AtSWEET17. Yeast functional complementarity tests showed that MeSWEET18 primarily transported fructose. qRT-PCR analysis showed that MeSWEET18 was highly expressed in tuberous roots during the expansion and decreased sharply at maturity of cassava tuberous roots, while the expression levels in leaf, petiole and stem increased with the development of cassava, and reached the maximum at the maturity stage of cassava. qRT-PCR analysis showed that MeSWEET18 was significantly affected by fructose when the hydroponic seedlings of SC9 were treated with sucrose, glucose and fructose solutions under dark conditions. The hydroponic seedlings of SC9 were subjected to abiotic stress including high salt (8 g/L NaCl) stress, drought (100 mmol/L mannitol) stress, oxidation (10% H₂O₂) stress and low temperature (15 ℃ for 24 h, then reduced to 4 ℃ for 24 h) stress. The results show that MeSWEET18 is expressed differently in leaf, petiole, stem and root under abiotic stress. It can be speculated that MeSWEET18 play an important role under abiotic stress in cassava.

Vertical greening is a technology that uses a new substrate to plant plants on the structure facade and vertical surface, which has been widely used in various urban scenarios. The performance of vertical greening substrate has fundamental research significance for three-dimensional greening cultivation. The effect of water and fertilizer maintenance effect of the substrate is the key factor to determine whether the vertical greening planting plants can survive and grow well. Curing soilless matrix is a cultivation material processed by artificial waste. It has the advantages of clean hygiene, stable nature and good cultivation performance. It is an ideal material for vertical greening cultivation. Retention effect of water and fertilizer is the key factor to determine whether survival and growth of plants in vertical greening, this study was based on the three types of solidified soil-free substrates, which are currently commonly used in vertical greening, including the soilless substrate 'Lei Tu', the Japan solid soilless substrate 'Pafcal' and the domestic solid soilless substrate 'Tan Mian'. Peat soil was selected as the control. The physical and chemical properties, retention of water and fertility were compared, and the potted experiment was executed to verify the effect on cuttage and griwth of plants. The 'Lei Tu' bulk density was small and the water holding capacity was strong, which had advantages over the other two substrates, but the air permeability of the three substrates was poor, so it needed to keep the plant gap in the planting process. The pH value of the 'Lei Tu' and the 'Pafcal' was more suitable for plant growth. The organic matter content and nitrogen content of the three substrates were higher than the natural soil. The concentration of nitrogen and phosphate loss of the three substrates in soluble experiments was extremely low, which would hardly cause the water body to be nutritious and affect the environment. The results of the three types of matrix solidification had reached experimental expectations, which had a significant advantage over peat, the traditional substrates. The effects of cuttings and growth of Callisia repens 'Pink Lady' of the 'Lei Tu' were the best and were the most ideal vertical greening substrate among the three tested substrates. The results would provide the theory of the cultivation of vertical greening.

Cymbidium eburneum and Cymbidium insigne are species endemic to Hainan exclusively and belong to the endangered species. 23 F₁ hybrid progenies from C. eburneum and C. insigne were used to accurately verify hybrids, to clarify the genetic relationships between hybrid progenies and the parents with SSR molecular markers. Eight pairs of primers were screened out from 48 pairs of primers using PCR, and 23 hybrid progenies were confirmed to be true hybrids, with the true rate of hybrid progenies100%. 23 hybrids populations identified by primers Cym45, Hub131 and Hub8 had both parental specific loci. 23 hybrid populations identified by primers Hub125 had only father specific loci, Cym9 had a new specific loci. Primer Cym25, Hub125 and Cym47 were low polymorphi [polymorphism information content (PIC)<0.25], primer Cym45, Hub131, Hub8 and Cym9 were middle-highly polymorphi (0.25<PIC<0.5). The PIC of primer Cym172 was 0.59, indicating that it was highly polymorphi, and could be used as the preferred primer for fingerprint construction of the progenies of C. eburneum × C. insigne. UPGMA cluster analysis results showed that when the genetic coefficient was 0.8111, the studied germplasms could be divided into three categories. Among which the parents constituted two categories, and the hybrid population belonged to the third. The hybrid population could be divided into three clusters, X₇ was a clade, X₆ and X₂₁ were clustered together, and the other 20 F₁ hybrid population s were the third. This study showed that SSR molecular markers could be used in hybrid identification and genetic diversity analysis of orchids species endemic to Hainan, which could provide an effective foundation and data base for orchid breeding and new species selection in Hainan. At the same time, the PIC of SSR molecular markers was an important indicator reflecting the ability of molecular markers. The middle-highly polymorphic primers and highly polymorphic primers developed in this study could lay a foundation for the construction of Hainan wild orchid gene atlas and the establishment and development of Hainan wild orchid germplasm bank.

The problem of heavy metal pollution of crops occurs frequently, and heavy metal pollution has become one of the important factors affecting crop quality. By applying 0.75, 1.50 and 3.00 g/kg potassium sulfate into soil under cadmium (Cd) stress, the effects of potassium fertilizer on the physical and chemical properties of rhizosphere soil and cadmium accumulation in plants of Ilex asprella were studied. This study is expected to lay a foundation for the development of cadmium excess reduction technology in Ilex asprella. The result shows that, the application of high amount of potassium sulfate fertilizer could reduce the soil pH by 1.72% to 8.09%. Cadmium stress can reduce the content of soil organic matter, and the application of medium (1.50 g/kg) and high (3.00 g/kg) amount of potassium sulfate can increase the content of soil organic matter, total potassium and available potassium. In addition, the application of potassium sulfate generally increased the content of biologically available cadmium in the soil, only on the 30th day after the application of low concentration of potassium sulfate (0.75 g/kg), the content of bioavailable cadmium in the soil decreased by 1.94% compared with the Cd treatment group. Under cadmium stress, the application of potassium sulfate could increase the SOD activity in leaves of Ilex asprella, and then enhance the tolerance to cadmium stress. Low could increase the SOD activity in leaves of Ilex asprella, and then enhance the tolerance to cadmium stress. Low concentration of potassium sulfate (0.75 g/kg) inhibited the transport of cadmium from rhizome to leaf and effectively reduce the accumulation of cadmium in the root and stem of Ilex asprella. To sum up, the application of high amount of potassium fertilizer decreased the soil pH, and the application of medium (1.50 g/kg) and high (3.00 g/kg) amount of potassium sulfate could increase the content of soil organic matter, total potassium and available potassium, thus improved soil fertility. The results also showed that low concentration of potassium sulfate could reduce the content of bioavailable cadmium in soil, inhibit the transport of cadmium from roots and stems to leaves, and reduce the accumulation of cadmium in roots and stems of Ilex asprella.

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 drying characteristics of Docynia delavayi at different temperatures (40, 60, 80 and 100 ℃) were investigated and a kinetic model was established to clarify the hot air drying characteristics and appropriate drying temperature for D. delavayi and to achieve its quality control in the hot air drying process. The effect of different drying temperatures on the dried product quality in terms of color, rehydration ratio (RR), the contents of active ingredients (polyphenols, flavonoids, polysaccharides) and antioxidant capacities were evaluated. The moisture ratio curve of D. delavayi decayed exponentially during the drying process, and the drying rate curve was divided into three stages, acceleration, constant rate and decreasing rate. With the increase of drying temperature, the moisture diffusion of D. delavayi intensified, and the drying rate increased obviously, the effective diffusion coefficient of water (D_eff) and activation energy (E_a) was 0.61×10^-6-1.78×10^-6 m²/s and 17.64 kJ/mol, respectively. The data analysis revealed that the Page model fitted well, with the coefficient of determination (R²) all above 0.98, and X², SSE in the range of 0.149×10^-3-0.548×10^-3 and 0.184×10^-2-0.493×10^-2, respectively, which could better reflect the variation pattern of D. delavayi according to moisture ratio with drying temperature during the hot air drying process. The quality of the D. delavayi exhibited some differences under different drying temperatures. D. delavayi dried at 40 ℃ had good rehydration that at 60 ℃ could maintain the maximum color, and possess the highest total polyphenols, total flavonoids, total polysaccharides content and better antioxidant capacities. The results of the post-drying quality analysis showed that temperature had a significant effect on the quality of D. delavayi, and 60 ℃ was better for the retention of color and active substances content. Correlation analysis showed that there was a correlation between color, rehydration ratio (RR), active substances content and antioxidant capacities of D. delavayi, while the active substances content was negatively correlated with the total color difference value (ΔE) and positively correlated with the rehydration ratio (RR) and antioxidant capacities. In addition, it also confirmed that the antioxidant capacities of D. delavayi were the combined effect results of multiple active substances. In conclusion, the quality of D. delavayi dried at the optimal temperature of 60 ℃ was more outstanding. The present study would provide an experimental basis for the further development and utilization of D. delavayi.

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.