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.

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.

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.

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.

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.

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 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.

As a distinctive intertidal ecosystem at the interface between terrestrial and marine realms, mangrove represents a pivotal buffer against the influx of microplastics (MPs) into the marine environment, which serves as a principal repository for MPs. To elucidate the inner differences in the temporal alterations in micro-morphology, physicochemical traits and bacterial communities of polyvinyl chloride (PVC) and polylactic acid (PLA), exposure experiments were conducted at the representative artificial and natural mangrove communities in Dongzhaigang Mangrove Nature Reserve in Hainan Province. Results revealed that MPs cultured in the natural mangrove performed more pronounced collapses and substantial fluctuations in contact angle, crystallinity, and hydrophobicity in comparison to that in artificial mangrove environment. This suggests that the natural mangrove environment exposure might accelerate the MPs aging processes. Significant differences were observed between the diversity of MPs bacterial communities and sediments in artificial and natural mangrove (P<0.05). Firmicutes plays a dominate role in MPs exposed to natural mangrove communities, while Proteobacteria was the dominant phylum colonized on MPs in artificial mangrove environment. The pH level of natural mangrove sediments was the primary factor for bacterial colonization on “plastisphere” (P<0.01), whereas ammonium nitrogen (NH₄⁺-N) of artificial mangrove habitats showed a highly significant positive correlation (P<0.01) with the microbial community of MPs. In summary, MPs in natural mangrove communities showed more pronounced alterations in the surface micromorphology and microbial community succession than that in artificial mangrove communities. The surfaces of the “plastisphere” in natural mangrove communities have a high level of bacterial community richness, and their ability to enrich microorganisms differs from that of the “plastisphere” in artificial mangrove environment. Results of the study provide a foundation for the dynamic changes in physicochemical properties and microbial communities of MPs, which is expected to contribute to further investigations in the potential risks of MPs.

The study was aimed to provide technical support for risk management, risk analysis and risk assessment of pests carried by banana seedlings in China. By consulting domestic and foreign literature (mainly including China’s National Pest Quarantine Information System, etc.), a total of 68 species of pests that may be transmitted to bananas exported to China were identified, including 32 species of insects, 19 species of fungi, 9 species of nematodes, 4 species of bacteria, 1 species of mollusca, and 3 species of mites (including spiders). Based on the distribution in China (undistributed or not widely distributed), whether they are officially controlled, and the possibility of being carried with banana seedlings, 9 potential quarantine pests were identified that require further evaluation, including 7 species of fungi and 2 species of bacteria. The 9 potential quarantine pests were qualitatively and quantitatively analyzed one by one in terms of entry, colonization, diffusion possibility, economic impact and multi-index comprehensive evaluation, and 5 species of medium-risk pests and 4 species of high-risk pests were identified. Finally, it was determined that the nine pests including Botryotinia fuckeliana were quarantine pests that require attention when banana seedlings were exported to China, and the corresponding risk management measures were put forward.

Meloidogyne enterolobii is one of the most devastating pathogens in tomato (Solanum lycopersicum) production. Grafting with resistant rootstocks could help superior cultivars gain root-knot nematode resistance straightly. Previously, we identified a medium-resistant tomato rootstock cultivar Guizhen 1. In order to deepen the understanding to its resistance mechanism, we inoculated Guizhen 1 and susceptible cultivar Yala with M. enterolobii, and measured the proportion of root knots and nematode numbers in roots once every four days within 28 days. The root knot proportion of Yala reached 71.7%, which was kept under 36.0% in Guizhen 1. The root knot proportions between resistant and susceptible cultivars were significantly different on day 12, 16, 20, 24 and 28 after inoculation. Whereas the differences of nematode numbers between resistant and susceptible cultivars were not significant except on day 20. Thus it can be seen that the resistance of Guizhen 1 was not reflected by limiting the invasion of nematodes. The LC-MS based non-targeted metabolome of resistant and susceptible roots on 5th day after inoculation were measured. With the threshold of VIP>1 and P<0.05, 415 significantly different metabolites were gained, among which 280 were up-regulated and 135 were down-regulated. The top 8 classes of metabolites with largest number of metabolites were amino acid and its metabolites, heterocyclic compounds, benzene and its derivatives, organic acid and its derivatives, aldehyde, ketone and ester, fatty acyls, glycerol phospholipids, alcohol and amines. KEGG dataset were employed to do the metabolite pathway enrichment analysis. Glycerophospholipid metabolism, ascorbate and aldarate metabolism, nicotinate and nicotinamide metabolism, betalain biosynthesis and flavonoid biosynthesis pathways had relatively high level of enrichment, with the glycerophospholipid metabolism having the highest enrichment level. In glycerophospholipid metabolism pathway, there were several metabolites with significant differences between resistant and susceptible cultivars, which were phosphocholine, phosphatidylcholine, lysophosphatidylcholine, sn-glycero-3-phosphocholine, triethanolamine and diethanolamine. It was speculated that glycerophospholipid metabolism pathway might enhance the M. enterolobii resistance of Guizhen 1 at certain level. In this study, the histological and metabolomic fundamentals of M. enterolobii resistance were explored in tomato rootstock cultivar Guizhen 1, which would provide certain basis for the in-depth study on resistance mechanism in the future.