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.

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.

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.

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.

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.

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.

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 nificantly 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.

Pineapple is prone to intern browning during storage at room temperature. Diseased and healthy parts of pineapple at early stage of intern browning were used to explore the mechanism of the disease. Three samples from each part were used for transcriptome RNA-Seq analysis. GO, KEGG, cluster analysis of gene expression in various metabolic pathways, and RT-qPCR validation on differential genes were performed and the differential gene expression levels between the diseased (IB) and healthy (WT) parts were compared. IB vs WT had 1037 differentially expressed genes, of which 886 were up-regulated and 130 were down-regulated. GO and KEGG analysis found that the differentially expressed genes in amino acid biosynthesis were the most significant, and the proportion of differentially expressed genes was large. Cluster analysis and RT-qPCR validation found that the sugar metabolism pathway significantly up-regulated the expression levels of related enzyme genes in glycolysis, tricarboxylic acid cycle (TCA), and oxidative phosphorylation processes after fruit disease onset. The response of plants to external environmental signaling pathways revealed a significant down-regulation of resistance enzyme gene expression, a significant up-regulation of pathogenic protein gene expression, and a significant down-regulation of resistance protein gene expression. The antioxidant pathway revealed significant down-regulation of glutathione synthesis gene expression, significant up-regulation of flavonoid biosynthesis related gene expression, significant down-regulation of L-ascorbate peroxidase (APX) gene expression, and significant up-regulation of L-ascorbate oxidase (AOX) homologous gene expression. RNA-Seq and RT-qPCR analysis indicated that pineapple tissue significantly up-regulated key genes in sugar metabolism to accelerate sugar metabolism in fruit disease part, significantly up-regulated key genes in the MAPK signaling pathway, and significantly down-regulated metabolic pathway changes such as antioxidant substances, leading to pineapple intern browning. The results could enrich the gene network of pineapple intern browning and provide a valuable reference for the subsequent gene screening of pineapple intern browning.

The introduction and evaluation of foreign clones play an important role in promoting the development of rubber trees in China. In order to evaluate the adaptability of Indonesian rubber tree clone Reshi 11-107, the stem circumference growth, dry rubber yield, rubber production and discharge characteristics, and natural rubber quality were examined in the clone trail test, which was arranged according to the breeding technical regulations. The average annual stem girth of Reshi 11-107 increased by 7.6 cm before tapping, and increased by 3.0 cm after tapping, and the fast-growing characteristics were obvious. The average yield was 58.41 g and the dry gum content was 33.37% in the first 5 tapping years, which were significantly better than that of the control clone RRIM600. Reshi 11-107 has a large number of laticifers in the bark, the initial flow rate of rubber discharge is fast, the plug index is low, the thiol content is significantly higher than that of the control, and the sucrose content is equivalent to that of the control. It has good characteristics of rubber production and discharge, better potential for rubber production, and good adaptability to cold damage. Reshi 11-107 natural rubber has large molecular weight, high ash content, high initial plasticity value, high tensile strength, high tear strength and good physical and mechanical properties. In conclusion, the comprehensive characters of Reshi 11-107 are better, which could adapt to the planting environment in China, and could be expanded in the type I planting area.

The triose-phosphate/phosphate translocator (triose-phosphate/phosphate translocator, TPT) is a triose phosphate transporter that plays an important role in plant carbon metabolism pathways as well as abiotic stresses. Sucrose has a wide range of edible value and important economic value. Sugarcane is the main raw material for sugar production, and sucrose from sugarcane accounts for more than 80% of China's sugar production, so it is very important to achieve the goal of high yield and high resistance of sugarcane. In this study, the sugarcane variety ROC22 was used as the material to clone the sugarcane triose/phosphate transporter gene ShTPT, and the physicochemical properties, conserved domains, transmembrane structure prediction and protein sequence comparison of ShTPT were carried out by bioinformatics methods. The results showed that the CDS of ShTPT was 1221 bp, encoding 406 amino acids, the molecular weight of the protein was 43.63 kDa, and the isoelectric point (pI) was 9.80. It was rich in alanine and leucine, its instability coefficient was 42.51, and its hydrophilic coefficient was 0.583, which was an unstable hydrophobic protein. ShTPT did not contain signal peptides but had 9 transmembrane domains. Conserved domain prediction showed that ShTPT contained a tpt domain, which was consistent with the characteristics of the TPT family. The results of phylogenetic analysis showed that ShTPT was clustered with Sorghum bicolor SbTPT (XP_002454867.1) and Zea mays ZmTPT (NP_001105497.1) with homology of 97.04% and 94.13%, respectively. Further subcellular localization analysis of ShTPT showed that ShTPT was localized in chloroplasts. Tissue expression pattern analysis of sugarcane showed that ShTPT was mainly expressed in leaves, and the expression level in roots and stems was very low. Under the drought stress conditions simulated by PEG, the expression of ShTPT showed an upward trend, indicating that it responded to drought stress. The results of this study suggest that ShTPT is a chloroplast-localized transmembrane transporter, which may be involved in the transport of primary carbon metabolic compounds in sugarcane leaves and responsive to drought stress. This study preliminarily determined that ShTPT gene plays an important role in the transport of carbon assimilates in leaves and abiotic stress, which provides a theoretical basis for further study of its function.