Ganoderma lucidum polysaccharides (GLPs), the main efficacy components of G. lucidum body, have remarkable efficacy in improving immunity, anti-tumor and liver protection and so on. In order to reveal the effect of gradient ethanol precipitation process on the structural characteristics and biological activity of GLPs, the crude GLPs were extracted from G. lucidum body using anhydrous ethanol to removal impurities such as pigments and hot water extraction process. GLPs were classified by gradient ethanol (40%, 50%, 60%, 70%, 80% and 90%) precipitation, and 6 GLPs, including GLP40, GLP50, GLP60, GLP70, GLP80 and GLP90, were obtained. The structural features of GLPs such as composition, functional group characteristics, molecular weight distribution, and biological activities such as in vitro antioxidant activity and the growth effect of Lactobacillus rhamnosus LGG were characterized by GC-MS, near infrared GC-MS, NIR spectroscopy, gel chromatography and other modern instruments. The results showed that the 6 GLPs contained rhamnose, xylose, arabinose, mannose, glucose and galactose, with glucose, mannose and xylose predominating, GLP40 mainly consisted of mannose and xylose, GLP50, GLP60, GLP70, GLP80 and GLP90 mainly consisted of glucose and mannose, and the highest percentage of glucose was found in GLP80 and GLP90. The typical functional groups of the 6 GLPs fractions at 892.9 cm^-1, 1048-1084 cm^-1, etc. were intact and did not differ significantly from each other, and all of them were β-type glucan conformations. The molecular weight of the 6 GLPs was different, and the heavy average molecular weight, number average molecular weight and peak molecular weight showed positive correlations. 97-14 925, 99-49 410, 98-32 030, 3614-19 589, 3614-10 795, 4385-11 084 g/mol, with preferential precipitation of high molecular weight GLPs at low ethanol concentrations. 6 GLPs had stronger DPPH radical scavenging ability, hydroxyl radical scavenging ability, and total antioxidant capacity, and GLP90 had stronger antioxidant activity than the other fractions. The 6 GLPs helped to promote the growth of L. rhamnosus LGG. The above findings would provide data support for the study of GLPs extraction process and product development.

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.

Based on the survey data in 2003 and 2019, the diversity of wetland vascular plants in Jianhu Provincial Nature Reserve in Yunnan was studied. The wetland plants were determined according to the standards issued by the State Forestry Administration and the division of relevant literatures. The results showed that there were 129 species of wetland vascular plants belonging to 83 genera and 34 families in Jianhu wetland, which could be divided into 12 distribution types and 12 forms. The temperate species accounted for 75.19% of the total number of wetland vascular plants in the reserve; There were 13 species endemic to China, accounting for 10.08% of the total number of wetland vascular plants in the reserve, including 4 species endemic to Yunnan, accounting for 3.10% of the total number of vascular plants in the wetland reserve. According to the classification and statistics of life forms, 92 species of hygrophytes, 19 species of submerged plants, 9 species of emergent plants, 5 species of floating plants and 4 species of floating leaf plants were obtained. The wetland vegetation consisted of 5 vegetation subtypes, hygrophyte type, emergent plant type, floating plant type, floating leaf plant type and submerged plant type, and 17 formations, for example, Polygonum hydropiper, Oenanthe javanica and Carexbolting sp. formation and Polygonum hydropiper, Polygonum amphibium and Polygonum strindbergii formation. According to the species habits, morphological characteristics, habitats and sources in the field investigation, it is determined that there were 4 categories and 63 species of secondary vascular plants in Jianhu wetland, and the floristic secondary degree was 48.84%. There were 39 species of wetland vascular plants in Jianhu Lake and Lashihai in Northwest Yunnan, with a species similarity of 22.29%, and 18 species of wetland vascular plants in Chenghai in Central Yunnan Province, with a species similarity of 10.00%, with a higher similarity with Lashihai. The results show that the vascular plants in Jianhu wetland are characterized by high species richness, significant temperate components, extremely low endemic rate, complete life forms, diverse community types, high floristic secondary degree and obvious components in Northwest Yunnan. The main reasons for the diversity of wetland vascular plants in Jianhu Lake are the high altitude, north latitude and serious human impact on Jianhu Lake, which are directly related to the characteristics of Jianhu Lake, such as shallow water, fast water replacement, low pollution, gentle lake bed inclination, large bank curvature and thick sludge at the bottom.

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.

In order to reveal the mechanism of flower development and provide a theoretical basis for solving the problems of flowering in the sugar apple industry, the Auxin Response Factor (ARF) family genes were identified and the expression patterns were analyzed. Based on transcriptome sequencing, 11 AsARF genes were selected and identified. The biological functions of AsARF family genes were preliminarily analyzed by homologous evolution analysis, protein domain analysis, subcellular localization, qRT-PCR, and other techniques. The AsARFs were divided into five classes based on phylogenetic analysis. The proteins had molecular weight varying from 73.85 to 112.51 kDa and isoelectric point from 5.42 to 7.63. All the AsARFs contained two domains of DBD and MR, and, except for AsARF3a, 6a and 6b, they also all contained a CTD domain. Subcellular location prediction results showed that the AsARF members were mainly located in the nucleus. Based on amino acid enrichment in the intermediate region of the protein, AsARF5a, AsARF5b, AsARF6c, AsARF6d, AsARF7 and AsARF16 were speculated to be transcriptional activators, while AsARF2, AsARF3a, AsARF3b, AsARF6a and AsARF6b were presumed to be transcriptional repressors. Three CTD domain-deleted ARF genes were identified and they may have unique biological functions. The results of subcellular location experiments showed that AsARF2, AsARF3a and AsARF6a were localized in the cell nucleus. Real-time quantitative PCR results showed that AsARF3a, AsARF3b, AsARF5a, AsARF5b, AsARF6a and AsARF7 genes were expressed more in the inflorescent meristem. AsARF2 and AsARF6b genes were highly expressed in flower buds. AsARF2, AsARF3a, AsARF5a, AsARF5b, AsARF6b, AsARF6c and AsARF16 genes were predominantly expressed in normal flowers, while the expression of AsARF3b, AsARF6a, AsARF6d and AsARF7 genes in malformed flowers was greater than that in normal flowers. These results suggest that AsARF may play key roles in regulating the flower development in sugar apple. The high expression of AsARF6b and AsARF6c in normal flowers and AsARF6a and AsARF6d in abnormal flowers indicate that they play important roles in the normal development of flowers.

Hirschmanniella spp. are migratory endoparasitic nematodes which are parasitic in the root of rice. They are widely distributed in different types of fields and have become serious parasitic nematodes to rice. The plant-parasitic nematode Hirschmanniella mucronate is one of the most serious rice nematodes in Jiangxi, China. At present, breeding and planting other disease-resistant varieties is the most economical and effective measure to control the disease. The significant up-regulated OsECH1 gene was screened by transcriptome analysis of healthy susceptible rice 'Bawangbian' root tissues and susceptible rice 'Bawangbian' root tissues infected by H. mucronata. Phylogenetic analysis of OsECH1 and its homologous proteins showed that OsECH1 and other homologous proteins had the same structure, including the same conserved domain PLN02874. And OsECH1 belonged to the ECH protein family. Besides, five homologous genes were found in the genome of 'Nipponbare' group and OsECH1 was located in Chr1. The full length of OsECH1 was cloned and the recombinant expression vector was constructed by homologous recombination technique. Meanwhile, the transgenic rice was transformed by GV1301. RT-qPCR was used to analyze the effect of OsECH1 gene expression level on the infection of H. mucronate in rice. The results showed that overexpressing OsECH1 in rice could reduce the infection of H. mucronata, while silencing OsECH1 in rice could significantly increase the infection of H. mucronata. The results of subcellular localization of OsECH1 showed that the protein was expressed in nucleus. And the results of His-tag pull down demonstrated that the protein may interacted with five defence-related proteins. The five defense-related proteins belonged to vATP-synt_E protein family, Ricin-B protein family, catalase and B_lectin protein family respectively. Meanwhile, RT-qPCR results showed that OsECH1 had regulatory effects on the five proteins. The results would provide a basis for further understanding the function of OsECH1 gene, and for understanding the molecular mechanism of OsECH1.

As one of the characteristic spice crops in tropical areas of China, the content of aroma components is the key index to identify the quality of Pandanus amaryllifolius Roxb. (Pa). Pa is suitable for planting under shade of Hevea brasiliensisr (Hb) forest in Hainan Island, China. However, the effect of Hb and Pa intercropping on the aroma component of the leaves of Pa has not been explored. Pot experiments were set up to compare the differences of soil physical and chemical properties and the types and content of aromatic composition in Pa leaves under intercropping and monoculture treatments. The intercropping mode significantly increased the soil bulk density by 13.63%, the content of soil alkali hydrolyzed nitrogen by 59.71%, the content of soil available phosphorus by 193.03%, the content of soil available potassium by 9.78% and the soil pH reduced by 1.00 (P<0.05). A total of 10 categories and 68 aroma components were detected in the intercropping and monocropping treatments. Compared with monocropping treatment, intercropping significantly decreased the number of ketones by 56.52%, furans by 14.29%, furanones by 33.33%, hydrocarbons by 20.00% and phenols by 28.57% (P<0.05). Although furans significantly reduced the content of aroma components by 65.28%, hydrocarbons by 20.88% and ketones by 69.00%, they significantly increased the content of alcohol by 31.50%, pyrrole by 597.56%, esters by 122.78% and furanone by 96.89% (P<0.05). The decrease of soil pH was the main reason for the reduction of ketones, furans, furanones, hydrocarbons and phenols. Intercropping indirectly increased the content of alcohols, pyrroles and esters and reduced the content of furans and hydrocarbons by reducing pH, while increasing soil available phosphorus and alkali hydrolyzable nitrogen. Pyrrole compounds were the main aroma components of Pa, thus the intercropping mode could significantly promote the quality of Pa. The results of this study would have a positive effect on the optimization and promotion of the Hb intercropping Pa mode, and also conducive to promoting the income increase of farmers and the sustainable development of related industries.

Artocarpus heterophyllus is popular for its sweet fruit and has a very promising market, but conventional seed propagation makes it difficult to maintain its excellent traits and the grafting method has a very low survival rate. The technique of tissue culture and rapid propagation has been widely used in the propagation of many rare and valuable plants, but there are no reports of its application in the production of A. heterophyllus. In the process of tissue culture, it was found that the stem tip of A. heterophyllus was severely browned, which led to the difficulty of establishing asexual reproduction system. In order to effectively investigate the measures to overcome the browning, this experiment took the stem tips of A. heterophyllus 'Haida 2' as the explants and inoculated them into different concentrations of PVP medium after low-temperature pretreatment at different lengths for primary culture, the browning rate and germination rate were calculated after 15 d, and PPO activity, total phenol and total flavonoid content were determined to explore the inhibition of different concentrations of PVP on browning in stem the tip tissue culture of A. heterophyllus after low-temperature pretreatment. The results showed that the browning rate of A. heterophyllus explants was the lowest and the germination rate was the highest after 12-24 h low-temperature treatment of stem tip and then in 1/2MS medium supplemented with 2.0 g/L PVP. The experimental results showed that this method was beneficial to the proliferation of A. heterophyllus explants. The purpose of this experiment is to promote the establishment of technique of tissue culture and rapid propagation for A. heterophyllus, with a view to providing a theoretical basis for the construction of the A. heterophyllus seedling breeding technology system and its industrial production demonstration.

Thielaviopsis paradoxa is harmful to almost all palm plants, among which stem bleeding of coconut is the most serious, and no effective and safe control method is available. Among the biocontrol bacteria screened in the early stage of this study, Pseudomonas aeruginosa wrj-2-5 and Alcaligenes faecalis brj-21 were proved to have biocontrol potential against T. paradoxa. In order to determine the specific inhibitory effect of P. aeruginosa and A. faecalis on T. paradoxa, T. paradoxa was used as the target strain to determine the bacteriostatic effect, indoor control effect and fermentation conditions of the biocontrol strains wrj-2-5 and brj-21. The results showed that wrj-2-5 and brj-21 both had a bacteriostatic rate of more than 70% against T. paradoxa. In vitro experiment found that the two bacteria still had good bacteriostasis. The lesion area of the treatment group was significantly smaller than that of the control group. Earlier inoculation would lead to better effect. In addition, the strains had strong inhibitory effect on other pathogenic bacteria of coconut leaf spot, fruit rot, gray spot and heart rot. The optimal fermentation condition of wrj-2-5 was rotation speed 180 r/min, temperature 28 ℃, culture time 36 h, initial pH value 6.0-8.0, and inoculum amount 8%. The optimal fermentation condition of strain brj-21 was inoculum amount 8%, the initial pH value 6.0-8.0, rotation speed 180 r/min, temperature 28-32 ℃, and incubation time 24 h. In conclusion, wrj-2-5 and brj-21 have good control effects on the stem bleeding of coconut and fruit rot of coconut caused by T. paradoxa. They also have a certain inhibitory effect on the pathogens of other coconut diseases, which would provide an important reference for the green and biological control of T. paradoxa.