To confirm the characteristics and difference of the chloroplast (cp) genome of Colocasia esculenta var. Redbud and Colocasia esculenta var. Lipu, the two taros were taken as experimental materials in the study, their genomic DNA were first extracted form fresh leaves using an improved CTAB method and the two complete cp genomes were obtained using high-throughput sequencing technology and bioinformatics analysis, simple sequence repeat (SSR) identification, multiple sequence alignment, sliding window analysis on DNA polymorphism and phylogenetic tree analysis were then conducted on two complete cp genomes. The results showed that the length of the complete cp genomes of Redbud and Lipu was 162 478 bp and 162 453 bp, respectively, exhibiting the typical cyclic quadripartite structure. A total of 131 genes were annotated both in the two, including 86 protein-coding genes, 37 tRNA genes and 8 rRNA genes, of which 18 genes had two copies and 23 genes had introns. A total of 130 and 124 SSR sites were identified in Redbud and Lipu respectively, the content of A/T in the SSR repeats was 63.08% and 61.29% respectively. 15 SSR polymorphic primers were identified. A total of 236 cp single nucleotide polymorphism (SNP) sites were detected between Redbud and Lipu, of which 26.7% were in the gene coding region, which leading to 25 missense variant genes, the variation of the genes may promote the difference between the two varieties. Compared with the representative species from 13 genus of Aroideae showed that the structure, types, and numbers of gene were relatively conservative. The trnS-trnG and ndhF-rpl32 were the highest variation sites in SSC and LSC region, respectively. The phylogenetics analysis using maximum likelihood method (ML) showed that the genus Colocasia had the closest relationship with the genus Steudnera, but the farthest relationship with the genus Sauromatum in the Ariodeae. The results would provide a theoretical basis for the germplasm resource exploitation, genetic diversity evaluation and phylogenetic analysis of C. esculenta.

Paurocephala sauteri, characterized by small individuals, rapid reproduction and overlapped generations, is the most damaging pest of mulberry trees in tropical and subtropical areas. It happens in seedling period, leading to yield loss over 40%, or even out of harvest, and is very difficult to control. In order to accurately predict and efficiently control the pest, and to improve the yield and quality of mulberry leaves, the internal reproductive system of the male and female adults of the pest in different developmental periods was dissected and observed to clarify the morphological characteristics and changes of the internal reproductive system of male and female adults of the pest before and after mating. Except for 2 pairs of lateral oviducts the composition of the internal reproductive system of the female adults is similar to Trioza erytreae (Del guercio), and male adults is highly similar to Diaphorina citri (Kuwayama). Compared with the pre-mating period, the length of spermatheca in mating and post-mating periods reached nearly 1.63 times and 1.85 times, and the width increased by about 1.74 times and 1.84 times respectively, with significant differences in each period (P<0.05), the length and width of eggs increased rapidly, to mating period increased by nearly 2 times (P<0.05). At the same time, several large vesicles appeared inside the egg in mating period and disappeared in post-mating period, them should be trophoblasts, providing nutrition for oocytes. Compared with the pre-mating period, the testes of the male increased to the maximum in the mating period and shrank to the minimum in the post-mating period. There were significant differences in the three periods (P<0.05), while the length and width of the seminal vesicle both significantly increased to about twice (P<0.05) in mating and post-mating periods. This study has practical significance to precisely judge and determine the appropriate period of prevention and control, to clone reproductive-related genes, to develop new gene targeting agents, and to formulate efficient prevention and control measures of P. sauteri.

C. camphora (L.) Presl is the most effective plant for extracting natural borneol in China. In order to help determine its proper habitat, this research plans to select branches and leaves of C. camphora (L.) Presl from eight habitats in China according to its habits, natural borneol of the leaves and branches of C. camphora (L.) Presl were extracted by steam distillation. The relative content of the chemical components in the extract was determined by GC-MS. The bacteriostatic circle diameter of Escherichia coli, Salmonella typhi and Salmonella enteritidis subsp was measured by the paper method, the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) were determined by 96 micro well plates. Chemical composition determination showed that the content of natural borneol extracted from the branches and leaves from different habitats was different, among them, d-borneol, camphor, d-limonene, eucalyptol, d-α-pinene, camphene, α-humulene and terpinen-4-ol were the common components, and the content of d-borneol was the highest, then camphor. The highest content of d-borneol was found from Yuan'an, Hubei, China (82.47%), and the lowest content was found from Ruyuan, Guangdong, China (41.63%). The natural borneol extracted from various habitats showed bacteriostatic effect on the three tested strains, and the diameter range of bacteriostatic ring was 14.60 to 27.95 mm, the minimum inhibitory concentration (MIC) ranged from 250 to 1250 μg/mL, the minimum bactericidal concentration (MBC) ranged from 0 to 1000 μg/mL. The natural borneol from Yuan'an and Jishui, Jiangxi had the best bacteriostatic effect, while that from Guangdong had the worst on the whole. In conclusion, the bacteriostatic activity of the extracts from the branches and leaves of C. camphora (L.) Presl is correlated with the content of its main components, and the habitat with the highest content of d-bornol has the best bacteriostatic effect, while the other has poor bacteriostatic effect. The data obtained in this research are accurate and reliable, and would provide a basis for the quality evaluation of the extracts of C. camphora (L.) Presl branches and leaves and the development of natural borneol resources.

Solanum xanthocarpum fruits are used as the test material, and the extraction process of chlorogenic acid is studied in detail by using the ultrasonic-assisted ethanol extraction test method. Values of four group parameters for the volume solubility of ethanol aqueous solution, ratio of liquid to the material, ultrasonic time, ultrasonic temperature were adjusted, and then the proposed extraction process parameters of chlorogenic acid from single-factor experiments and the corresponding results were optimized. The optimized parameters were ethanol concentration 65%, ratio of liquid to material 50 mL/g, ultrasonic temperature 60 ℃ and ultrasonic time 40 min. On the basis of the above single factor optimization results, the final quadratic multiphase mathematical model was obtained further by optimization from the Box-Behnken response surface method. The extraction process parameters were ethanol concentration 64.7%, liquid-to-solid ratio 55.8 mL/g, and ultrasonic temperature 56.0 ℃ for 40.5 min, and the optimal extraction rate of chlorogenic acid was 6.81%. The extract of S. xanthocarpum fruits had good antioxidant capacity to DPPH and ABTS free radical scavenging with IC₅₀ values of 55.7 mg/L and 20.1 mg/L, respectively.

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.

Soaking the harvested fruit with chemical fungicides is a general method for fruit preservation. However, due to the concerns of consumers about chemical residues and the lack of postharvest treatment conditions in litchi producing areas, there is an urgent need to develop green, environment-friendly preservation techniques for litchi, which is also easy to apply. In this study,'Jingganghongnuo' litchi was sprayed with 5 mmol/L sucrose solution at the latter stage of fruit development (10 days before harvest), and stored at room temperature (20 ℃) after harvest. The results showed that, compared with the control, pre-harvest sucrose treatment reduced the browning index, disease index and decay rate of harvested litchi, decreased the chromaticity a^* value and increased the L^* and b^* values, indicating that sucrose treatment improved the appearance quality of litchi. The sucrose-treated litchi was not significantly different from the control in the content of soluble solid (TSS) and titratable acid (TA), although they were slightly lower than that of the control in the content of Vc, suggesting that it had no significant adverse effect on nutritional quality. Sucrose treatment inhibited the activities of polyphenol oxidase (PPO) and peroxidase (POD) in litchi pericarp, reduced the contents of relative conductivity (REC), malondialdehyde (MDA), hydrogen peroxide (H₂O₂) and superoxide anion (), and increased the activity of phenylalanine ammonia lyase (PAL) and total phenol content in litchi pericarp, so as to delay the browning and decay of litchi. This study shows that pre-harvest sucrose treatment, as a new litchi preservation technology, has a certain prospect for application in litchi producing areas in China.

Tobacco mosaic virus (TMV) is a major factor leading to the yield reduction of Solanaceae crops. In order to explore edible fungus-derived polysaccharide materials for the prevention and control of Tobacco mosaic virus, the control effect of six crude polysaccharides against TMV was determined by the half-leaf method, five-point injection test and systematic host infection activity evaluation. Among them, the extraction rate of crude polysaccharide from Agaricus blazei, 24.32%, was the highest, followed by Pleurotus ostreatus 18.56%, and that from Pleurotus eryngii, 10.04% was the lowest. The total sugar content of A. blazei was significantly higher than that of other species, reaching 37.71%, followed by that of P. igniarius and G. Lucidum, exceeding 32.00%. In addition, the sulfate content of A. blazei crude polysaccharide was also as high as 2.10%. In this research, the inhibitory effect of the crude polysaccharides was determined by the half leaf method. Among the 6 tested polysaccharide treatments, the polysaccharides that were inoculated after treated for 48 h had a good inhibition on TMV. The preventive effects of P. ostreatus, C. versicolor and A. blazei reached more than 60.00%. Especially, the preventive effect of 24 mg/mL A. blazei crude polysaccharide was up to 92.04%, and the number of dead spots on the leaves was significantly less than those in the clear water control group. In the five-point injection test, the inhibition rate of A. blazei crude polysaccharide was 38.18%. The brightness of the fluorescent spots was weaker than that in the control group, the fluorescent area did not change much, and did not appeared in the new leaves. A. blazei crude polysaccharide had an inhibitory effect in the early stage of virus infection, which could delay the moving speed of TMV and slow down the system invasion process. On NC-89, the control effect of agaricus antler polysaccharide on TMV was as high as 76.81%, which was better than that of 0.5% lentinan water agent and 1.8% octinamine acetate water agent. When the concentration was 48 mg/mL, the plants were damaged, and the excessive concentration of polysaccharide formed precipitation on the surface of the plants, causing the plants to yellow. Field test showed that the treatment effect of A. blazei crude polysaccharides on TMV was 70.31%. The plants with twisted, curled leaves and stopped growing had an obvious improvement. At the same time, it had a certain inhibitory effect on TMV, the onset time of sprayed tobacco was delayed, the tobacco grew well, and the leaves were extended. The results of this study would lay a foundation for further study on the action mode and mechanism of fungal polysaccharides against Tobacco mosaic virus.

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.

Mulching with plant residues is a common method used in agricultural and forestry production, which has significant effects on soil moisture conservation, soil fertility improvement, plant growth promotion and solving the problem of soil bareness. In recent years, the application of green waste to urban green land mulching is the focus of landscape industry in China and abroad and the main application and development direction of compost besides returning to soil. At present, the research and application of green waste mulch mainly focus on composting mulch and dyeing mulch, and there are few reports on the systematic comparison of the mulch effects of different components of native materials. For proven after simple processing green waste native materials mulching influence on plant growth, taking Ixora chinensis Lam. as the research object, the green wastes were collected according to turfgrass clippings (TCS), leaves (LVS), mixture of branches and leaves (MBL), branches (BCS), and then were crushed, air-dried as native mulches material to test and set up three mulching thickness (3 cm, 6 cm and 9 cm), with bare soil without mulch as the control. The effects of different treatments on growth parameters, mineral nutrients and SPAD of above-ground parts of I. chinensis Lam. were analyzed after 21 months of planting. The results showed that compared with the control, mulches significantly increased the plant height, stem diameter, biomass, SPAD and N content in stem and leaf of I. chinensis Lam. The variation trend of P content in stem and leaf and K content in stem of each treatment was different due to the difference of mulch material type and thickness, but had no obvious effect on leaf K content. The results of correlation analysis showed that there was a very significant positive correlation between the growth parameters and the N content of stems and leaves and SPAD, and the P content was significant positive correlated with the weight of fresh leaves. Comprehensive evaluation by principal component analysis indicated that mulches treatments on each index of the comprehensive performance of I. chinensis Lam. was superior to the control. Treatments could be divided into two categories according to principal component comprehensive, category one, MBL & BCS with the thickness of 3 cm, 6 cm, 9 cm LVS with 6 cm and 9 cm with better effect on promoting the growth of Ixora chinensis Lam., and category two, TCS with thickness of 3 cm, 6 cm, 9 cm and LVS with thickness of 3 cm with relatively poor growth promoting effect. This study screened out the components and mulching thickness of green waste raw materials suitable for organic mulch through comparative evaluation of the indexes affecting the growth of I. chinensis Lam., which could provide reference for the promotion and application of green waste as organic mulch.