Grapefruit of Guipuyou No. 1 planted in Guangxi has high and stable yield, and the flesh is juicy, suitably acidic and sweet. The widely targeted metabolisms of flesh was determined, the differential metabolites were screened and the metabolic pathway was analyzed to understand the difference of flesh composition at different maturity stages. A total of 529 metabolites were detected from grapefruit of Guipuyou No. 1, including 159 flavonoids, 64 Phenolic acids, 64 amino acids and derivatives, 53 others (saccharides and alcohols,vitamin, others), 51 lipids, 40 lignans and coumarins, 34 nucleotides and derivatives, 29 alkaloids, 28 organic acids, 5 terpenoids and 2 tannins. The differential metabolites at different maturity stages mainly included flavonoids, phenolic acids, amino acids and their derivatives, lipids, lignans and coumarins, and most of them were down-regulated. The down-regulated types of phenolic acids, amino acids and their derivatives, lipids and other types increased, and most of them showed a continuous downward trend with the increase of fruit ripeness. Most of the down-regulated flavonoids showed a sharp decline in the early stage of fruit ripening, and then increased in the late stage of fruit ripening. The types of down-regulated flavonoids first increased and then decreased, with the most in the middle stage of fruit ripening. The relative contents of synephrine, spermidine, betaine, shikimic acid were consistently decreasing. The relative content of limonin increased in the early stage of fruit ripening, and decreased significantly in the middle and late stage of fruit ripening. The most significant enrichment pathway of differential metabolites was flavonoid biosynthesis in the early stage of fruit ripening, but it was phenylpropanoid biosynthesis during the whole ripening process. The fruit of G₂ had the best taste, with soluble solids of 12% and solid-acid ratio of 23.24, which was suitable for fresh eating. However, phenolic acids such as caffeic acid and ferulic acid, flavonoids such as isoquercitrin and hyperoside decreased significantly during this period. There were many kinds of metabolites in the pulp of grapefruit of Guipuyou No. 1, which was rich in nutritional and functional components. The best picking time for fresh food is from late October to middle November. Fruits used for health care or medicinal purposes should be picked in advance according to the efficacy requirements. This study would provide a theoretical basis for the study on the nutritional and functional components of grapefruit of Guipuyou No.1, and provide a reference for the best harvest maturity of its different uses.

Plant peroxidase (POD) plays a role in plant development, hormone signaling, and stress response, but there are few research reports on the POD gene in mango. This study used mango genome data as a reference and employed bioinformatics methods to identify members of the POD gene family from multiple aspects, including protein characteristics, phylogenetic relationships, gene structure, promoter cis acting elements, and gene expression patterns. The expression patterns of POD gene family members under enhanced UV-B irradiation through transcriptome and quantitative real-time PCR (qPCR) experiments were analyzed. The mango POD (MiPOD) gene family had a total of 77 family members, and the genes were then mapped to 17 chromosomes and 2 scaffolds, encoding amino acids with a number of 206~500 aa, Stable proteins were accountted for the majority, most of them were hydrophilic proteins. Most MiPOD were predicted to localize in subcellular within chloroplasts, and classified into seven subgroups using phylogenetic analysis. The gene structure among members of the subgroup were similar. The results of collinearity analysis indicated that the proportion of MiPOD genes involved in segmental duplication was relatively high. It was speculated that it may be related to the expansion of the MiPOD family. The selection pressure analysis indicated that the K_a/K_s values of collinear genes were far less than 1, indicating that MiPODs may be mainly subjected to purifying selection during the evolutionary process. The MiPODs promoter region contained a large number of light responsive, hormone responsive, and stress responsive elements. MiPOD had different expression patterns, which may be related to its different protein functions. MiPOD exhibited different expression patterns during fruit growth and development under enhanced UV-B irradiation, with only MiPOD7 showing significant differences in expression levels among the highly expressed members. MiPOD7 expression levels were significantly higher than those of the control under UV-B stress, suggesting that it may play an important role in the response of mango fruit to UV-B stress. In summary, members of the MiPOD gene family may have evolved through segmental duplication and intron reduction patterns, and perform different functions by sensing different types of signals, thus forming different expression patterns. This research would lay the foundation for further studying the response mechanism of mango POD genes to different signals.

Lysophosphatidyl acyltransferase (LPAT), a key enzyme which controls the production of lysophosphatidic into phosphatidic, plays an important role in phospholipid biosynthesis in plants. Hevea brasiliensis is an important source for the production of natural rubber, which has an irreplaceable role in the fields of national defense, medical treatment, high-end products, and has high social and economic value. Cloning and analysis of HbLPAT2 in H. brasiliensis would provide scientific basis for further exploration of its phospholipid biosynthesis function and the effect of phospholipid on nature rubber. In this study HbLPAT2 was cloned from the latex of the H. brasiliensis by molecular biology techniques, and the bioinformatics analysis, expression analysis and subcellular localization analysis were performed. In this study, two key genes responsible for phospholipid biosynthesis in the HbLPAT gene family were successfully cloned from the latex of the H. brasiliensis, named HbLPAT2a and HbLPAT2b, the full length coding sequence of HbLPAT2a and HbLPAT2b genes was 1161 bp and 939 bp, encoding 386 and 312 amino acids. Both HbLPAT2a and HbLPAT2b contained a PLN02380 lysopyatidyl acyltransferase functional domain and contained a highly conserved NH(X)₄D motif; HbLPAT2a protein had 3 transmembrane domains, and HbLPAT2b protein had 1 transmembrane domain, both of which had no signal peptide, were hydrophilic proteins, and contained multiple phosphorylation sites. The subcellular localization analysis showed that both HbLPAT2a and HbLPAT2b proteins were located in the endoplasmic reticulum. In different organs, the highest expression level of HbLPAT2a and HbLPAT2b was found in seeds, suggesting that they have a lipid biosynthesis function. However, in the latex of H. brasiliensis, the first and second expression level of whole HbLPAT gene family were HbLPAT2a and HbLPA2b. The result is helpful to understanding that HbLPAT2a and HbLPAT2b play an important role in the phospholipid biosynthetic pathway in latex of H. brasiliensis and to providing a scientific basis for genetic improvement of latex quality of H. brasiliensis.

Vacuolar invertase (VIN), degrading sucrose to produce glucose and fructose irreversibly, is a key enzyme in soluble sugar metabolism, and involved in plant growth and development, yield and quality formation, and stress resistance. To investigate the physiological functions of VIN genes in soluble sugar metabolism of red pitaya (Hylocereus polyrhizus), HpVIN1 gene was cloned from the fruit, and sequence comparison, phylogenetic relationship, gene expression, subcellular localization, yeast growth complementation and sucrose degradation activity were analyzed. Based on RT-PCR (reverse transcription-polymerase chain reaction) amplification, the ORF (open reading frame) of HpVIN1 gene with a length of 1935 bp was isolated, which encoded 644 amino acids. Sequence analysis showed that HpVIN1 contained key domains related to sucrose degradation activity of invertase, as well as vacuole localization sequences in the N terminal. Phylogenetic analysis suggested that HpVIN1 was closely related to VIN genes from kiwifruit, loquat, apple and grape. Real time fluorescence quantitative PCR detection revealed that HpVIN1 was highly expressed in stems and fruits during the veraison stage (20~25 days after flowering), and weakly expressed in ripen fruits (30 days after flowering). The transient expression of HpVIN1 fused by green fluorescent protein in Arabidopsis thaliana mesophyll protoplasts demonstrated that HpVIN1 protein was localized in the tonoplast and vacuole. By over-expressing in the yeast strain with sucrose utilization defects, HpVIN1 could restore the yeast growth using sucrose as the sole carbon source, which proved that HpVIN1 had the sucrose degradation activity. In vitro catalytic experiment using the yeast total protein suggested that HpVIN1 could degrade sucrose into glucose and fructose. The sucrose degradation activity was the highest at pH 4.0, and rapidly decreased as pH value increasing. The results show that HpVIN1 that locates in the vacuole, has the enzyme activity of degrading sucrose to produce glucose and fructose, and participates in sucrose catabolism of stems and fruits during the veraison stage.

Papaya ringspot virus (PRSV) is one of the most serious diseases in papaya production, with high incidence rate, rapid transmission and serious harm. To detect papaya plants infected with PRSV in a timely manner, this study established methods for detecting papaya plants infected with PRSV using enzyme-linked immunosorbent assay (ELISA) and fluorescence quantitative reverse transcription PCR (qRT-PCR). The two methods were used to detect the PRSV content of multiple transgenic and non transgenic papaya plants, and the results were compared. The results showed that the standard curve established using PRSV peptide antigen as the standard and antibodies prepared from it had good fitting, and could be used for ELISA detection of PRSV; The reference gene Cpa03g018830 selected in qRT-PCR method was stably expressed at different growth stages of papaya and could be used as a reference gene for PRSV content determination; The detection results of PRSV content in multiple transgenic and non transgenic papaya plants using ELISA and qRT-PCR methods were basically consistent, indicating that both methods can be used for the detection of PRSV content in papaya plants. By using thee two detection methods, papaya plants infected with PRSV can be detected and eradicated in a timely manner, effectively preventing and controlling the spread of PRSV.

Phosphorus is one of the essential nutrients for plant growth, and plays a crucial role in determining crop yield and quality. Due to the combined pressure of decreased arable land quality and soil phosphorus deficiency or low bioavailability, the improvement of soil phosphorus availability has become a global concern. The rotation of two or more crops has positive effects on soil improvement, crop production efficiency and the restoration of agricultural ecosystem function. This study reviews the research progress on the effects of crop rotation on soil physiochemical properties, soil phosphorus transformation, and soil micro-food web. Firstly, the relationship between soil properties and phosphorus transformation is analyzed to assess the impact of crop rotation on phosphorus availability. Secondly, from the perspective of soil micro-food web and gene regulation, the transformation and biogeochemistry cycle of soil phosphorus was analyzed at the molecular level. It is summarized that crop rotation can affect soil phosphorus transformation through altering soil physiochemical properties and micro-food network structure, which can improve soil phosphorus availability, and ultimately promote crop yield and quality. We indicate that crop rotation is an important agricultural management measure for improving soil phosphorus availability. It is suggested to strengthen the related research and explore the combination model of crop rotation in the future. It would provide powerful support for food security and crop quality, and is of great significance in social economy and ecological environment.

Using the robusta coffee Reyan 1 as the scion and liberica coffee Chali 5 as the rootstock, grafting was carried out using the inarching method to investigate the effect of interspecies grafting on the growth of coffee grafted seedlings. Two sets of inarching methods were set up (cutting off the top of the rootstock first and then grafting, and grafting first and then cut off the top of the rootstock after surviving), and then transplanted into three types of soil (clay, loam, and sandy soil) and four different coffee continuous cropping years (0, 5, 10, 20 a) soil, and the robusta coffee self grafted seedlings were used as CK to study the effect of interspecific inarching on the survival rate, growth index, chlorophyll content, and growth and degradation of grafted seedlings in the different soil types and in the different coffee continuous cropping years soil. Results showed that grafting at the same stage of scion, the survival rate of F₂ treatment (grafted seedlings with preserved aboveground parts of the rootstock) was significantly higher than that of F₁ treatment (grafted seedlings without preserved aboveground parts of the rootstock). Using the same method, grafting at the “Butterfly” stage of the scion, the survival rate of grafting seeding was significantly reduced compared to grafting at the “soldier” stage. Different grafting methods could significantly affect the survival rate of coffee grafted seedlings, and the younger age of the scion seedlings was beneficial for improving the survival rate of grafted seedlings. The treatment of F₁ increased the root system, root to shoot ratio, and promoted the increase of aboveground biomass, resulting in faster plant growth. In the early stage of F₂ treatment, the biomass of the aboveground part was high, which promoted the growth of the underground part. Cutting off the top of the rootstock after surviving relatively reduced the biomass of the aboveground part, inhibited the growth of the root system, which reduced the biomass of the root system. Different soil types had a significant impact on the growth of the root system of grafted seedlings. In clay, the root system of robusta coffee seedlings was more developed than that of liberica coffee seedlings, while in sandy soil, the root system of liberica coffee seedlings was more developed than that of robusta coffee seedlings. As the grafted seedlings grew, if the root system of robusta coffee seeds was not cut off in time after grafting and surviving, the root system of liberica coffee seedings would slowly deteriorate with growth. In soils with different coffee continuous cropping years, the survival rate of interspecific inarching seedlings was 100%, significantly improving the survival rate, effectively alleviating continuous cropping obstacles, improving survival rate, and restoring aboveground growth. On the 2-3 days after grafting, the parenchyma cell in the cortex began to coalescent. On the 4th day, callus tissue could be seen between the rootstock and scion. On the 6-8 days, 2/3 of the stem segments between the rootstock and scion had already healed, and healing was evident on the 8-10 days. Using liberica coffee as rootstocks and robusta coffee as scions, the method of cutting off the top of liberica coffee seeding first and then inarching during the “soldier stage” of the scion can obtain vigorous interspecific grafting seedlings, which can effectively alleviate soil continuous cropping obstacles and improve coffee growth.

As an imported crop, date palm lacks planting management experience in China. It is imperative for the development of Chinese date palm industry to select suitable nutrients, construct the date palm rooting system quickly and efficiently, ensure the full absorption of nutrients by the roots during the field planting period, and shorten the growth cycle of date palm. In order to study the effects of different microalgae fertilizer on the growth of date palm seedlings of “Mabroom” and “Sillege” varieties, fresh microalgae (M₁), fermented microalgae solution (M₂), microalgae nutrient solution (M₃) and microalgae circulation solution (M₄) were selected to treat the seedlings. The growth and physiological indexes (leaf length, relative permeability of cell membrane, malondialdehyde MDA, peroxidase POD, catalase CAT, glutathione reductase GR) of date palm seedlings were measured. The results showed that the leaf length of “Mabroom” seedlings was significantly higher than that of the control group after treatment with microalgae nutrient solution (M₃) and microalgae circulation solution (M₄), and the microalgae nutrient solution (M₃) and microalgae circulation solution (M₄) could promote the growth of “Mabroom” seedlings. The osmotic regulation ability of leaf cells was strong. The contents of catalase, peroxidase and malondialdehyde were lower than those of the control. After treatment with fresh microalgae (M₁) and fermented microalgae solution (M₂), the leaf elongation length of “Sillege” seedlings was significantly higher than that of the control, and fresh microalgae (M₁) and fermented microalgae solution (M₂) were more suitable for the growth of “Sillege” seedlings, with fresh microalgae (M₁)>fermented microalgae solution (M₂). The osmotic regulation ability of leaf cells was higher than that of the control. The change of catalase content was lower than that of the control. This study showed that during the cultivation of microalgae, the microalgae nutrient solution (M₃) and microalgae circulation solution (M₄) could synthesize related active substances to produce primary metabolites. Such bioactive substances were absorbed by seedling roots and promoted the elongation and growth of date palm leaves. The “Mabroom” seedlings were more suitable to apply the secondary metabolites of microalgae as fertilizer. “Sillege” date palm seedlings are more suitable for fresh and fermented microalgae.

Frequent pre-harvest fruit abscission occurs during the development of longan fruits due to insufficient carbohydrate supply. The metabolism of carbohydrates is closely related to energy metabolism, and changes in energy charge related respiration and carbohydrate consumption, which are important indicators for measuring fruit physiological functions. In order to reveal the relationship between abnormal abscission and energy charge of longan fruits, this study used the fruits of the late stage of development (80 days after flowering) of “Chu Liang” longan as the materials, and used ear girdling plus defoliation treatment to block carbohydrate supply and artificially create hunger stress, which can lead to complete fruit abscission within 5 days. During this process, this study analyzed the changes in ATP, ADP, and AMP contents and energy charge levels in different tissues during fruit abscission. The results showed that the energy charge values of different tissues in the fruit were as follows: seeds>fruit skin>fruit flesh, and with the intensification of starvation stress, during the fruit abscission process, ATP significantly decreased and AMP significantly increased throughout the experiment. The energy charge values of different tissues showed a downward trend, but the decrease in seed energy charge value was the smallest, and the seed was the organ with the most stable energy charge. The results indicated that starvation stress could lead to a decrease in fruit energy levels, but the magnitude of energy changes varied among different tissues, seeds could maintain relatively stable energy charge levels, suggesting that under starvation stress, fruit resources prioritized the supply of seeds, thereby maintaining the energy state.

Photosynthesis plays a crucial role in the growth and development of plants, and the light response curve can describe the relationship between photosynthetic rate and light intensity under different light conditions. As a thermocrop plant, clarifying the photosynthetic characteristics of Noni is crucial for understanding its growth and development process, while there are relatively few reports on the photosynthetic aspects of Noni. In order to study the photosynthesis of Noni and its environmental adaptation, this study took Noni with four shade treatments (CK, T₁, T₂, T₃) as the research object, and measured the daily change of light intensity, daily change of net photosynthesis and light response curve by LI-6400 portable photosynthesizer, and used four commonly used light response models to fit, and then screened the optimal model to obtain the corresponding photosynthetic characteristic parameters. The daily change of light intensity showed a single-peak parabolic trend, and the daily light intensity reached the maximum at 12∶00 noon, while the daily change of net photosynthesis of Noni showed an inverted U-shaped change, with a rapid increase from 6∶00 to 10∶00, and a slow decline from 10∶00 to 16∶00, and a rapid decline at 16∶00. The daily changes of the two existed some synchronous and non-synchronous changes. The net photosynthetic rate (P_n) and light intensity (I) both showed obvious decreasing trends with the increase of shade between different treatments. The modified model of the right-angle hyperbola (MRHM) fit most effectively for the light response curve of Noni. With the exception of 90% shade, both the root mean square error (RMSE) and mean absolute error (MAE) were lower than those of the other three models, ranging from 0.06 to 0.12 and 0.05 to 0.09, respectively. With the increase of shade, the photosynthetic apparent quantum efficiency (AQE), maximum net photosynthetic rate (P_nmax), light saturation point (LSP) and dark respiration rate (R_d) of Noni gradually decreased, while the light compensation point (LCP) gradually increased, indicating that under the induction of low light, the photosynthetic efficiency of Noni gradually decreased, and the photosynthetic efficiency of Noni gradually decreased when over-shaded. This indicates that the photosynthetic efficiency of noni decreases gradually under low light induction, and even decreases dramatically under excessive shade, and its high photosynthetic efficiency can only be activated under strong light stimulation. This study reveals the photosynthetic characteristics of Noni and its response strategy to different shade, which would provide a theoretical basis for the deep understanding of Noni ecological adaptation, and also provide a reference for the production of Noni understory planting or shade measures.

Camellia spp. is an important woody oil in China, which plays an important role in ensuring national grain and oil security. Previous studies showed that the self-incompatibility of Camellia spp. may be one of the important reasons for the low seed setting rate. In this study, fluorescence microscopy and morphological observation were adopted. C. hainanica Reyan 2 and Reyan 3 were used as the material, and the self-cross and hybrid combinations were Reyan 3×Reyan 3, Reyan 3×Reyan 2, respectively. Samples were collected after self-cross and cross-pollination. The difference of pollen tube growth between the two groups was compared by fluorescence microscopy. The results showed that there were different degrees of curvature at the front end of the stigmas, the number of stigmas ranged from 3 to 5, and the pistil length was slightly larger than the stamen length. The length of pistil was positively correlated with the number and length of stamen. The single flower opening lasted for 5‒8 d, and the time of pollen dispersal overlapped with the time of stigma receptivity. Pollen tube fluorescence observation showed that the growth rates of autocross and outcross pollen tubes of Reyan 3 Camellia hainanica were roughly the same in the early stage, and the growth rates of both reached the peak within 12‒24 h after pollination. After 36 h, the growth length of hybrid pollen tube exceeded that of autocross pollen tube until it grew into ovary. 48 h after pollination, both inbred and outbred pollen tubes could reach the base of the style, and it was observed that the outbred pollen tubes could enter the ovary, but the growth rate of the inbred pollen tubes slowed down until the growth stopped at the base of the style near the ovary. The results would provide a theoretical basis for the variety configuration and efficient cultivation of C. hainanica.

Longan (Dimocarpus longan Lour.) is native to southern China and widely cultivated in the southern and southeastern regions. It is a fruit tree with high economic value. Longan seeds, as a typical recalcitrant seed, are highly sensitive to low temperature and drying, making them difficult to preserve in traditional low-temperature seed banks. After excluding the influence of ice crystals on seeds, this study conducted vitrification freezing and direct freezing ultra-low temperature storage on fresh and dry seeds, and compared the changes in physiological and biochemical indicators, contents, and starch. After dehydration and ultra-low temperature storage, longan seeds almost lost the vitality. Compared with healthy seeds, dehydration led to a significant increase in malondialdehyde content and severe damage to cell membranes. The hydrogen peroxide content showed a decreasing trend. The expression of antioxidant enzyme system increased, and the highest SOD activity was observed in longan seeds with a water content of 16% after vitrification and freezing treatment, while vitrification and freezing treatment reduced the activities of POD and CAT. Low temperature and dehydration led to an increase in the content of soluble sugars and proteins in seeds, while dehydration led to protein denaturation and a decrease in content. Observing the starch of longan seeds, it was found that after vitrification and freezing treatment, there were voids and depressions on the surface of starch particles, which were directly frozen and caused starch particle rupture. Dehydration and low temperature did not affect the molecular structure of starch, but caused some degree of damage to the internal ordered structure.

Pitaya fruit is a characteristic tropical fruit of Hainan province, mainly cultivated in the red soil of Hainan province. The exchangeable magnesium is lost throughout the year, leading to magnesium deficiency in some orchards, which affects the growth and yield of pitaya fruit. Magnesium is involved in photosynthesis and other metabolic processes. Therefore, this study took the main domestic variety of pitaya Dahong as the experimental material, using hydroponic experiments, set four magnesium concentration gradients of 0, 0.5, 2.0, 4.0 mmol/L, to determine the changes in the apparent morphology, biomass, and the activity of enzymes related to crassulacean acid metabolism in pitaya fruit. The results showed: (1) Different magnesium concentration treatments had a significant impact on the length, width, thickness, stem thickness, and fresh weight of the tender stems of pitaya fruit. When magnesium is deficient or excessive, the length, width, thickness, stem thickness, and fresh weight of the tender stems are also significantly less than those treated with 2.0 mmol/L. Magnesium deficiency can significantly reduce the length, width, thickness, stem thickness, and fresh weight of pitaya fruit. The condition of 2.0 mmol/L magnesium concentration is most suitable for plant growth; (2) The activity of PEPC first increased and then decreased with the increase of magnesium concentration. The activity of PEPC at 4 mmol/L magnesium concentration was lower than at 2.0 mmol/L but higher than at 0.5 mmol/L and 0 mmol/L treatments. after 84 days, under the condition of 2.0 mmol/L magnesium concentration, the PEPC activity in tender and old stems was the highest among other treatments, at 90.44±1.40 and 92.77±0.67 nmol/(min·g), respectively, and its initial CO₂ fixation ability was much higher than other treatments; The activity of NAD-MDH in tender stems decreased with the increase of magnesium concentration. With the extension of treatment time, the impact of magnesium concentration on NAD-MDH gradually appeared, first observed in tender stems and then gradually affected the old stems. The maximum activity of tender and old stems treated with magnesium deficiency after 84 days was (12631.82± 286.04)nmol/(min·g), and (10500.16±108.34) nmol/(min·g), respectively; Under the treatment of 2.0 mmol/L magnesium concentration, the activity of NAD-ME in both tender and old stems of pitaya fruit was maintained at a high level, with an overall average of 28.41~ 65.87 nmol/min/g. (3) Magnesium deficiency had a significant effect on the enzyme activities of PEPC and NAD-MDH in tender stems. Magnesium deficiency reduced the activity of PEPC, leading to a decrease in oxaloacetic acid content, limiting the process of CO₂ conversion to malate. The accumulation of malate at night is reduced, and the raw materials for photosynthesis are insufficient during the day, thereby reducing the accumulation capacity of organic matter. Conclusion: The optimal magnesium concentration for the cultivation of domestic red-fleshed pitaya is 2.0 mmol/L. The magnesium concentration in the soil of the current pitaya planting area is lower than this value, so it is recommended to reasonably increase the application of magnesium fertilizer during the planting of pitaya.

In order to investigate the edible quality of different provenances of areca nuts, this study was carried out to determine the contents of cellulose, hemicellulose, lignin, protopectin and arecoline, and to analyze the textural structure of hardness, chewiness, viscosity, springiness and cohesion of areca nut from different varieties planted in Hainan. The results showed that there were significant differences between different provenances of areca nuts in terms of fruit shape, hemicellulose, chewiness, viscosity, cohesion and arecoline content. HN-TY showed good quality characteristics of soft fiber and high viscosity. HN-YG had the least hardness and high elasticity. HN-TY and HN-CG had high arecoline contents of 5910.61 and 7121.70 μg/g, respectively. In addition, among all the traits, arecoline content varied most frequently among betel nuts of different varieties and the coefficients of variation were large. Protopectin content was the most unstable, with the coefficients of variation ranging from 27.78% to 74.88%. The coefficients of variation for each trait of the TW were generally large, resulting in a rich genetic diversity. The present study would provide information on the important quality of different provenances of areca nuts available in Hainan province, while the determination of the coefficients of variation of thirteen trait indexes of areca nuts in six groups provide a basis for parental selection in areca nut improvement.

Cassava, commonly known as the “underground granary”, serves as the food staple for more than one billion people globally. Additionally, it is a prevalent and advantageous crop in southern China. Recently, the food security situation has intensified, leading to an increased emphasis on the utilization of cassava in China. Therefore, the breeding of new sweet cassava variety holds immense importance. In this study, using a self-crossing segregating populations and SNAP molecular marker assisted technology, a new sweet cassava variety, Gui 11 was bred. This variety exhibits a compact plant shape, with light yellow fleshy roots. The hydrogen cyanide content in its fresh tuberous root is 12.30 mg/kg, and it yield is 43.35 t/hm², presenting 24.64% higher than the current main sweet cassava variety 'South China 9'. Additionally, the fresh tuberous root of Gui 11 contains 38.40% dry matter, 28.20% starch, 4.71% soluble sugar, and 1.80% crude fiber, and it displays moderate resistance to Tetranychus cinnabarinus. The successful breeding of Gui 11 exemplifies the effective utilization of molecular marker technology to assist in the selection of new cassava varieties through self-crossing segregating populations. This advancement offers technical and variety support for promoting the transformation and enhancement of the cassava industry.

The purpose of this study is to explore the relationship between the activity of Lvnonglin^®31 compound microbial agent (LNL31), the occurrence of blister blight and the structure of endophytic bacterial communities in tea, and to provide a theoretical basis for the rational application of microbial agents for green control of blister blight in Camellia sinensis var. assamica. The activity of LNL31 was evaluated through indoor antibacterial spectrum testing, laser confocal microscope morphology observation, pathogenic fungus spore germination inhibition rate test, and transparent circle detection enzyme activity methods. Field randomized block trials were carried out to test the disease prevention and growth promotion effects of LNL31 with different dilution ratios. Then the tea tree bud length, bud density, fresh weight and chlorophyll were respectively measured. Using 16S rDNA sequencing technology, the differences in the occurrence of the blister blight in C. sinensis var. assamica and the community structure of endophytic bacteria in leaves under LNL31 were investigated. The diluted LNL31 had obvious inhibitory effect on five pathogens, such as Exobasidium vexans EV01, Colletotrichum gloeosporioides CG02, Fusarium oxysporum FOC4, Xanthomonas axonopodis pv. citri XC01 and Escherichia coli DH5α, which caused the hyphae to break, expand and digest. The inhibition rate of LNL31 on spore germination of pathogenic fungi EV01, CG02 and FOC4 reached 89.04%-93.00%. In field randomized block trials, the application of 500-fold dilution of LNL31 had the most significant disease prevention and growth promotion effect, which was similar to the treatment of the pyraclostrobin, followed by 1000-fold dilution of LNL31. The averages of bud length, germination density, hundred bud weight and chlorophyll of the plants in the treatment of LNL31 increased by 23.14%-36.17%, 32.10%-51.38%, 27.66%-40.00% and 28.88%-36.14%, respectively, in comparison with the control. After spraying different concentrations of LNL31, the richness and uniformity of endophytic bacterial communities increased, and the results of principal coordinate analysis (PCoA) showed that there was a significant impact on bacterial communities in leaves. At the taxonomic level, Rhizobiales and Sphingomonadales were the dominant bacterial orders; Methylobacterium was the dominant bacterial genus, followed by 1174_901_12, Sphingomonas and Rhizobium. Linear discriminant analysis (LEfSe) showed that there were 9-14 indicator bacterial groups in the treatment sprayed with LNL31, compared with only 7 indicator bacterial genera in the control. Cluster analysis of species abundance showed that the unique dominant genus Baierinkia and Burkholderia in the treatment of LNL31 were similar in abundance, while Rhizobium and 1174_901_1 were similar in abundance. Correlation network analysis Bacillus is positively correlated with Eubacterium and Parabacteroide, and negatively correlated with Methylobacterium, Beijerinckia and Luteibacter. Bugbas’s functional prediction showed that the abundance of aerobic bacteria, biofilm forming, gram-negative bacteria, stress-tolerant bacteria, movable elements, and facultative anaerobic bacteria treated by the composite microbial agent increased by 3.24%-14.78%, and potential pathogenic bacteria dropped by 5.70%. LNL31 showed a good effect of preventing diseases and promoting growth, and significantly changed the community structure and functional characteristics of endophytic bacteria in tea, enabling a few disease-resistant related species to grow in an advantageous way, which provided a basis for biological control of blister blight of tea.

In this study, the microbial community was analyzed by high-throughput sequencing technology in the soil of rubber plantation with different yield levels (high yield, middle yield, low yield and none yield), and relationship between microbial community and soil physical and chemical properties was also studied. A total of 2116 bacteria OTUs were obtained from all examined samples, which belonged to 17 phyla, 53 classes, 99 orders, 164 families, 305 genera and 385 species. The dominant phyla of bacterial community were Acidobacteria, Proteobacteria and Firmicutes. A total of 1622 fungal OTUs were obtained from all soil samples, which belonged to 17 phyla, 49 classes, 113 orders, 242 families, 424 genera and 644 species. The dominant phyla of fungal community were Basidiomycota, Ascomycota and Mortierellomycota. The abundance of soil bacteria community showed a downward trend was observed with the decreasing of the yield level of rubber trees, while the difference of bacterial diversity index was not significant. Ace index and Chao1 index of soil fungi showed an upward trend, and Shannon index significantly increased, while the Simpson index decreased significantly, indicating that the richness and diversity of fungal community increased with the decreasing of the yield level. Principal coordinate analysis (PCoA) showed that the community structure of soil bacteria or fungi was significantly different under the treatments. In addition, the relative abundance of dominant bacterial phyla also varied to different degrees. The characteristics of soil microbial community were closely related to soil pH and C/N. According to redundancy analysis (RDA) results, soil pH, available potassium and total nitrogen were the main soil physical and chemical factors affecting the dominant bacterial phyla, while the dominant fungal phyla were mainly affected by soil pH, available potassium and C/N.

The growth and development of pitaya are closely associated with the rhizosphere microbiome, yet there is a lack of understanding regarding the seasonal characteristics of the microorganisms during the fruit’s production cycle. This study focused on the red-fleshed pitaya in Hainan, utilizing high-throughput sequencing technology to investigate the dynamics of the rhizosphere microbial community across different seasons and its correlation with soil physicochemical factors. The results indicated that the richness and diversity of the pitaya rhizosphere microbial community were seasonally driven. There were significant differences in the Ace index, Chao1 index, Shannon index, and Simpson index among the microbial communities across seasons, particularly showing an increasing trend in autumn. A total of 6132 bacterial OTUs and 1850 fungal OTUs were obtained from 12 rhizosphere samples collected throughout the four seasons. Bacterial OTUs were classified into 43 phyla, 135 classes, 319 orders, 502 families, and 963 genera, while fungal OTUs were classified into 15 phyla, 42 classes, 103 orders, 214 families, and 423 genera. The phyla Firmicutes, Actinobacteria, and Proteobacteria showed stable and dominant relative abundances across the four seasons, making them the predominant bacterial phyla. The genus Bacillus maintained the highest relative abundance within the bacterial community, making it the dominant bacterial genus; however, its relative abundance was significantly higher in spring and winter compared to summer and autumn. The phylum Ascomycota was the dominant fungal phylum in the pitaya rhizosphere. The genus Chaetomium was the dominant fungal genus, with a notably higher relative abundance in spring compared to other seasons. Differential species analysis revealed 15 bacterial differential species and 3 fungal differential species across the four seasons. The physicochemical properties of the pitaya rhizosphere soil showed significant seasonal variation and were closely related to the rhizosphere microbial community. FAPROTAX predictions indicated that the pitaya rhizosphere bacteria primarily exhibited functions such as chemoheterotrophy, aerobic chemoheterotrophy, ureolysis, nitrate reduction, cellulolysis, nitrogen fixation, aromatic compound degradation and animal parasites or symbionts. FUNguild predictions showed that the pitaya rhizosphere fungi mainly displayed saprotrophic lifestyles and some unknown functions. In summary, this study demonstrated that the structure of the rhizosphere microbial community associated with red-fleshed pitaya in Hainan undergoes significant changes across the four seasons, with the highest diversity and richness observed in the fall. Bacillus and Chaetomium were identified as the dominant bacterial and fungal genera in the rhizosphere, respectively. The findings could provide a theoretical basis for designing cultivation improvement measures based on rhizosphere microbiota for pitaya.

Mikania micrantha is one of the first invasive species in China, which poses a big threat to the ecological security of subtropical regions. Soil enzyme activity inhibitors and plant growth regulators play central roles in plant growth regulation. In this paper, the effects of different concentrations of soil enzyme activity inhibitors [1 g/L and 15 g/L NBPT, N-(N-butyl) thiophosphate triamide, 1 g/L and 15 g/L nitrification inhibitor DMPP] and exogenous plant regulators (25 mg/L and 50 mg/L ABA, abscisic acid, 1 g/L and 10 g/L CCC, chlormequat) on the growth of M. micrantha during its vigorous growth period, budding period, flowering period, peak flowering period, and seed setting period were studied through a 7-month continuous pot culture experiment. The results showed that high and low concentrations of soil enzyme activity inhibitors and plant growth regulators had different effects on the growth status of chamomile and the content of alkaline hydrolyzed nitrogen and available phosphorus in the soil. Among them, chloramphenicol and DMPP had a significant inhibitory effect on chamomile, while 15 g/L NBPT had a promoting effect on chamomile growth. In summary, 10 g/L chloramphenicol had an inhibitory effect on the vigorous growth of chamomile, while 15 g/L DMPP had an inhibitory effect on the vigorous flowering period of chamomile. The combined application of the two could provide a theoretical basis for the comprehensive prevention and control of chamomile throughout its lifecycle.

In order to provide technical support for risk management, risk analysis and risk assessment of pests carried by citrus seedlings in China were carried out. Through consulting domestic and foreign literature, a total of 259 species of pests that may be transmitted to banana seedlings exported to China were determined, including 53 fungus, 9 bacteria, 9 viruses, 11 nematodes, 167 insects, 1 mollusc, 1 weed, 8 mites (including spiders). According to the distribution of pests in China (not distributed or not widely distributed), whether it is officially controlled, and the possibility of carrying with banana seedlings, 18 potential quarantine pests were determined to be further evaluated, including 4 fungus, 7 bacteria, 4 viruses, 2 nematodes and 1 insect. The 18 potential quarantine pests were qualitatively and quantitatively analyzed one by one in terms of entry, colonization, possibility of spread, economic impact and comprehensive evaluation of multiple indicators, and 14 high-risk pests and 4 extremely high-risk pests were identified. The quarantine risk of citrus seedlings imported to China was determined to be extremely high based on the highest risk level among all quarantine pests. Finally, 18 types pests including Bisifusarium dimeru on citrus seedlings imported to China were identified, and corresponding risk management measures were proposed.

In order to enhance the antifungal activity of Streptomyces samsunensis 17-7 strain and effectively utilize its secondary metabolites, this study focused on optimizing the fermentation medium formula. Orthogonal and single factor experiments were conducted based on the original medium, with Phellinus noxious as the indicator. The optimal formulation for producing active substances from the strain was determined to include 25 g/L soy powder, 10 g/L corn meal, 10 g/L glucose, 2 g/L yeast extract, 1 g/L K₂HPO₄, 0.5 g/L NaCl, and 0.5 g/L CaCO₃. Following a 500 times dilution, the relative antifungal activity of the fermentation solution increased to 51.37%, a 17.66% improvement compared to the previous optimization, demonstrating a broad spectrum of antifungal activity. The stability of the antifungal substance was evaluated in response to various conditions such as temperature, pH, protease, UV-irradiation, and storage. Results indicated that the fermentation broth of strain 17-7 exhibited high temperature resistance, a significant decrease in antifungal activity after one hour of UV irradiation, but retained its activity after long-term exposure to UV light. Furthermore, the broth demonstrated good acid-base tolerance, effective antibacterial activity in the pH range of 3-10, and resistance to trypsin and pepsin. The fermentation broth of strain 17-7 maintained its antifungal activity for 120 days at both 4 ℃ and room temperature (25 ℃). This study on the stability and storage conditions of strain 17-7’s fermentation broth offers valuable data for potential future applications of the strain as a biocontrol agent.

The biological macromolecules such as polysaccharides and terpenes in Sanghuangporus spp. aqueous extract have inhibitory effects on tumor cells, but the function was not yet clear. This study obtained small molecule compounds of Sanghuangporus sanghuang Sheng H. Wu, L. W. Zhou & Y. C. Dai and Phellinus baumii aqueous extracts through 3000 D ultrafiltration, and studied the inhibitory activities on mouse hepatocarcinoma cells Hepa 1-6 using dual fluorescence labeling. The anticancer active ingredients were analyzed using metabolomics analysis. The results showed that the small molecule compounds of S. sanghuang Sheng H. Wu and P. baumii could induce injury and apoptosis of Hepa 1-6, with inhibition rates of (38.64±4.35)% and (32.52±3.57)%, respectively. Meanwhile, the inhibition rates of small molecule compounds reached (77.27±6.21)% and (76.92±5.45)%, respectively, after mixing with crude polysaccharides. Metabolomic analysis showed that anti-cancer small molecular agents such as ellipticine, betonicine, cerebroside-B etc., were identified in the aqueous extract of Sanghuangporus spp. Antitumor related substances such as heterocyclic compounds (6-fluoroindole, 2,4,6-trimethylpyridine, 1'-naphthoyl-2-methylindole, etc.), nucleoside and bases (1-methyladenosine, N6-methyladenosine, 2'-O-methyladenosine, etc.), dipeptides (leucine+*, isoleucine+*, γ-glutamine+*, etc.), sugar alcohols (xylitol, ribose, mannitol, erythritol, etc.), were identified too. The results indicate that the aqueous extract of Sanghuangporus spp. contains multiple small molecular agents against tumor cells, which have a synergistic anti-cancer effect with biological macromolecules such as polysaccharides. This would provide a scientific basis for understanding the mechanism of anti-tumor of Sanghuangporus spp. and the development and application of functional substances.

The bottom fraction of the latex from the Brazilian rubber tree (Hevea brasiliensis), specifically the biological membranes that includes lutoids and the Frey-Wyssling complex, may undergo changes in its membrane lipids and membrane proteins. The changes could affect the coagulation rate of the latex during the tapping process and the speed of blockage of the incision of the latex vessels, thereby preventing the flow of latex and reducing yield. Two types of rubber trees with rapid and normal coagulation rates of latex were selected. Liquid chromatography-mass spectrometry technology (with both positive and negative ion detection modes) was used to qualitatively and quantitatively analyze the lipids in the bottom fraction of the two types of latex, obtaining information on differential lipids. In the bottom fraction of the latex from trees with normal coagulation rates, phosphatidylethanolamine was the most abundant phospholipid subclass (accounting for about 22% of total lipids in negative ion mode and about 5.9% in positive ion mode); it was greater than phosphatidylcholine (about 12% in positive ion mode and about 4% in negative ion mode); phosphatidic acid had a high abundance (about 4% in positive ion mode and about 12% in negative ion mode), comparable to phosphatidylcholine; cardiolipin was abundant in the bottom fraction (about 6% in negative ion mode) and may be present in the Frey-Wyssling complex. In the rubber trees prone to rapid coagulation, cardiolipin in the bottom fraction significantly decreased to about 3.4% in negative ion mode. The phospholipids in the bottom fraction accounted for 31%-56%, neutral lipids 35%-54%, and glycolipids only 1%-2%. The bottom fraction contained a high abundance and quantity of non-bilayer phospholipids, namely phosphatidylethanolamine, phosphatidic acid, and cardiolipin, showing a highly dynamic nature of the latex bottom fraction. The significant downregulation of cardiolipin in the latex prone to rapid coagulation may affect the stability of the bottom fraction, thereby affecting latex coagulation, laticifer blockage, and latex flow. The discovery of high abundant non-bilayer phospholipids in bottom fraction in this study introduces a new perspective into the research of latex coagulation and laticifer blockage mechanisms.

Starch sodium octenyl succinate is a food additive produced by the process of esterification using starch and octenyl succinic anhydride. In this study, the tapioca starch sodium octenyl succinate was prepared and characterized with non-alcohol esterification by substituting the organic reagent-dispersed OSA with the OSA emulsification technique. The results showed that OSA emulsion prepared with soybean phospholipid (SP) as an emulsifier had good stability and dispersibility. The octenyl succinic acid group content, degree of substitution, and substitution efficiency of 1.00% SP-SSOS made using OSA emulsions with 1.00% SP emulsifiers were found to be greater compared to IPA-SSOS made using isopropanol-dispersed OSA. FT-IR showed that 1.00% SP-SSOS and IPA-SSOS had two new characteristic peaks at 1572 cm^-1 and 1726 cm^-1, with 1.00% SP-SSOS having a stronger peak intensity. Confocal laser scanning microscopy confirmed that the fluorescence intensity of the fluorescence-labeled OS group was slightly stronger in 1.00% SP-SSOS, and a few starch particles contained OS groups inside. The results indicated that the use of high-pressure homogenization and emulsifiers to disperse OSA into micron-sized oily droplets for esterification could increase the contact area between OSA and starch, improving the efficiency of the esterification reaction. To summarize, it is possible to produce SSOS by utilizing the OSA emulsification technique as an alternative to organic reagents for dispersing OSA. This study would provide a reference for the application of an alcohol-free esterification reaction system in the large-scale industrial production of SSOS.

Coconut oil residue (COR) and coconut milk residue (CMR) are the two main by-products of coconut meat, which are produced during the processing of coconut oil and coconut milk, respectively. In order to explore the processing suitability of the two by-products, the nutritional and physicochemical properties of the two by-products were comprehensively analyzed. The results showed that the fat content of COR (19.37 g/100 g) was lower than that of CMR, while the nutrients such as protein (11.32 g/100 g), total dietary fiber (63.92 g/100 g), soluble dietary fiber (4.42 g/ 100 g), polysaccharides (25.67 mg/g), flavonoids (4.21 mg/g), total phenols (1.15 mg/g) and other active ingredients were higher than those of CMR. The hydrolyzed amino acids of COR and CMR were similar, but the content was significantly different, which was 94.955 mg/g and 56.975 mg/g, respectively. COR showed better hydration properties than CMR at different temperatures, but the fluidity of both was poor. COR had relatively higher thermal stability, more complete crystal structure and higher group activity than CMR. In conclusion, compared with CMR, COR has more nutrients and active ingredients, hydration properties and fluidity, and has higher thermal stability and stable crystal structure, which is an ideal raw material for low-fat, low-sugar and high-fiber food processing. The results of this study could provide theoretical guidance for the high-value utilization of coconut meat processing by-products in the food industry.