In order to explore the application of coffee protein in food processing, non-fat green coffee powder was used as the raw material. Different ultrasonic powers (0 W, 200 W, 400 W, 600 W and 800 W) effect of synergistic interaction with deep eutectic solvent method and alkali method on composition (SDS-PAGE), structural properties (particle size distribution, Fourier transform infrared spectroscopy, circular dichroism spectrum, fluorescence spectroscopy and scanning electron microscopy) and functional properties (solubility, water absorption, oil absorption and emulsification) of coffee protein were studied. The average particle size of coffee protein (DES) extracted by deep eutectic solvent (12.30 μm) was significantly smaller than that of coffee protein (AEP) extracted by alkali method (113.67 μm). The solubility of DES was higher under acidic conditions, and the solubility of AEP was higher under alkaline conditions. DES had better water and oil absorption than AEP. After ultrasonic pretreatment, the results of coffee protein electrophoresis, Fourier infrared spectrum, circular dichroism spectrum and fluorescence spectroscopy showed that different ultrasonic power pretreatment did not cause significant changes in protein molecular weight distribution, but it affected the secondary and tertiary structure of proteins. The surface microstructure of DES showed that the surface structure was loose and porous, and the surface of AEP was tight and flat. After ultrasonic pretreatment, the microstructure of AEP became loose and porous, the texture became dispersed, and more irregular fragments were presented. The surface of DES changed slightly, and showed more small-particle porous disordered structure when treated at 400 W and 600 W for 15 min. The microstructure changes could affect the chemical and physical properties and functional properties of proteins. When the ultrasonic power was 400 W, the particle size of DES decreased significantly, and the particle size parameters D_[3,2] and D_[4,3] decreased from 10.50 μm, 30.43 μm to 7.89 μm and 11.27 μm, respectively. The solubility increased significantly, and the solubility increased from 47% and 71% to 75% and 81% respectively under acidic and alkaline conditions. In addition, ultrasonic pretreatment could improve the water absorption and emulsification activity of coffee protein, which are important functional properties of proteins in food applications. The results show that the modification of coffee protein by ultrasonic technology is effective, and this study could provide a theoretical basis for the application of coffee protein in food processing.

Citrus is one of the most important fruits in China, and its post-harvest occurrence of citrus green mold is a serious threat to the quality and safety of citrus, and also causes mycotoxin contamination in the fruit. A strain of Streptomyces sp. R₂A-15 with good antagonistic effect on the pathogen of citrus green mold was isolated from the root soil of red orange plants in the red orange orchard of Jiuzhoujiang, Lianjiang, Zhanjiang city, Guangdong province. The optimization of the fermentation conditions and stability analysis of the bacterial inhibition activity were studied to provide reference for the preparation and application of the biocontrol agent of citrus green mold. In this study, Penicillium digitatum was used as the target fungus, and the fermentation broth was used as the inhibitory activity according to the size of the diameter of the inhibition zone by paper diffusion method. The fermentation medium of strain R₂A-15 was optimized using one-way and cross-combination tests, and the fermentation conditions were optimized by response surface analysis to improve the inhibitory activity of the fermentation broth, and the stability of the fermentation broth was investigated under different acid-base, temperature and ultraviolet light conditions. The optimum carbon source for the fermentation medium of the strain was cornmeal and the optimum nitrogen source was acid-hydrolyzed casein in the one-way and cross-combination tests. Based on response surface analysis, it was concluded that cornmeal and fermentation time had a significant effect on the bacteriostatic activity of the fermentation broth. The optimal fermentation medium for maximum inhibitory activity of the fermentation broth, as determined by validation tests, was 12.09 g of cornmeal, 4.00 g of acid-hydrolyzed casein, 2.00 g of calcium carbonate, 2.00 g of magnesium sulfate, 2.00 g of dipotassium hydrogen phosphate, 1.00 g of sodium chloride, and 1 L of distilled water. The optimal fermentation conditions were: initial fermentation pH 7.0, fermentation time 37.50 h, fermentation temperature 34 ℃, inoculum volume 3%, and shake flask filling volume 100 mL/250 mL. The bacteriostatic activity of the fermentation broth of the strains increased by 39% after optimization. The overall bacteriostatic activity of the fermentation broth of the strain could be maintained at a relatively stable and high activity level after treatment with different temperatures and ultraviolet light conditions, but the bacteriostatic activity of the fermentation broth decreased under strong acid and alkali. The results indicate that Streptomyces sp. R₂A-15 has a good and stable inhibitory effect on the citrus green mold pathogen, and has a good prospect for practical application, which lays a foundation for the later scale fermentation as well as the development of bacterial agents.

Natural rubber, a crucial industrial raw material worldwide, and a significant part of the income for Laotian farmers, is influenced by alternative planting policies and fluctuations in rubber prices. Aaccurate and rapid monitoring of local artificial rubber plantation is of crucial significance for promoting the sustainable development of the rubber industry. Most research has focused on the extraction of rubber plantation information in small areas, typically utilizing single or dual-temporal image classification, which fails to capture the long-term expansion characteristics of rubber forests. To investigate the long-term, large-scale expansion features of rubber plantation, this study selected a continuous thirty-year Landsat time series imagery from 1990 to 2020. The LandTrendr algorithm was employed to extract changes in rubber plantation across Laos over the three decades. International rubber futures prices and terrain data were also utilized for spatiotemporal change analysis. The selected feature combination, after optimization, can better extract rubber forest distribution. The overall accuracy of rubber forest distribution extraction in 2020 was 89.85%, with a Kappa coefficient of 0.82, revealing Laos’ rubber plantation area to be 321 000 hectares in 2020. The overall accuracy of rubber forest expansion change monitoring using the LandTrendr algorithm and secondary classification was 92.44%, with a Kappa coefficient of 0.82. The expansion of artificial rubber forests in Laos was closely related to the rubber futures market. Through terrain factor analysis, it is deduced that rubber forests are suitable for planting in low-altitude, gently sloping, and sunny areas. This study effectively monitors changes in rubber forests at the national level over an extended period, providing valuable data support for the development of the rubber industry and policy control.

In order to obtain the structural mechanical property parameters of rubber bark and solve the problem that there is no reliable reference for accurate detection of rubber depth and accurate control of skin loss thickness in the research and development of mechanized rubber picking equipment, a test device for nonlinear mechanical property measurement of rubber bark based on PLC was designed to realize automatic continuous detection and data collection of rubber bark mechanical properties with high precision and low loss measurement of bark thickness. The mechanical properties of bark of 15-, 20- and 25-year-old rubber trees of Reyan 7-33-97 and PR107 were studied, and the mathematical model of piercing force with piercing depth was established. The experimental results showed that the performance of the device was stable, and the piercing force curves of different strains and different ages were similar, showing a high-low-high trend, and were highly correlated with the layered characteristics of the bark structure. Under the same age, the piercing force of two strains of Reyan 7-33-97 and PR107 was not significantly different, and the piercing force of older trees of the same strain was greater than that of younger trees. The maximum piercing force reached 48.5 N. The test device meets the requirement of detecting structural mechanical parameters of rubber bark and provides theoretical basis for the research and development of mechanized rubber harvesting equipment.

This paper reports a new record Orchidaceae genus—Vandopsis Pfitz, and two new record species—V. gigantea (Lindl.) Pfitz and Dendrolirium tomentosum (J. Koenig) in Guangdong province. The detailed morphological description, habitat distribution and color photos are provided. The findings expand the distribution range of those taxons and is of great significance to the flora study.

Dendrobium are famous for the ornamental and medicinal value. In order to explore the volatile components in the flowers of Dendrobium in Sect. Holochrysa and Sect. Chrysotoxae Kraenzl., the volatile components in the flowers of five Dendrobium in Sect. Holochrysa and seven Dendrobium in Sect. Chrysotoxae Kraenzl. were extracted by solid phase micro extraction (SPME) and analyzed via gas chromatography-mass spectrometry (GC-MS). Results showed that 74 volatile components were identified from the flowers of the species, 47 of which from D. hancockii in Sect. Holochrysa were the main volatile components; Secondly, there were 37 and 35 volatile components from D. chrysotoxum and D. harveyanum in the Sect. Chrysotoxae Kraenzl., respectively. The least component species was D. farmeri in the Sect. Chrysotoxae Kraenzl. with only 18 volatile components. Most of the species of volatile substances in Dendrobium were more than 20, and most of which were alkenes, except D. kenkinsii and D. densiflorum in the Sect. Chrysotoxae Kraenzl. mainly contained aldehydes. Cluster analysis of volatile ingredients showed that all the Dendrobium flowers were clustered together except a few Dendrobium plants were not clustered in the original grouping, which indicated that the volatile substances in Dendrobium flowers could be used as a reference for Dendrobium grouping. This study would provide references for the breeding, resource exploration and utilization of Dendrobium, and exert significant value on the grouping of Dendrobium.

The effects of long-term nutrient deficiency on cassava agronomic characters, yield and starch content were studied to provide scientific basis for fertilization of continuous cropping. In this study, experimental materials in 2019 to 2021 (continuous cropping in 28th-30th years) were selected from the time axis of long-term fertilization trials. CK (with NPK), –N (without N), –P (without P), –K (without K) combined with two cassava varieties SC205 and SC124 were selected. The SPAD value, plant height, stem diameter and starch content, yield, starch yield of the fresh storage root (FSR) were measured and evaluate. Compared to CK, –N and –K significantly reduced plant height, and –N, –P and –K significantly reduced stem diameter of cassava. Meanwhile, –K significantly reduced SPAD value of leaves. Test of between-subjects effect showed that, variety or fertilization had significant effects on agronomic characters, but the interaction effect between them was not significant. The starch content of FSR, compared to CK, –N significantly improved in 2021. –K significantly reduced, the three-year average decrease was 14.2%. Compared to CK, –N, –P and –K significantly reduced the yield, starch yield of FSR, storage root number per plant (SRNPP) and weight per storage root (WPSR). The yield of FSR reduced by more than 40.0% under different nutrient deficiency, while the yield effects were insignificantly different among nutrient deficiency treatments. The starch yield of FSR under -K decreased by 53.3%, the decrease was significantly higher than that of –N and –P. The correlation analysis showed that yield, starch yield of FSR were extremely significantly positively correlated with the SRNPP, and significantly positively correlated with the WPSR. –N, –P and –K significantly inhibited cassava growth. N was the primary limiting factor for cassava fresh storage root yield in the early stage of continuous cropping, followed by K, but P effect was not obvious. With the extension of continuous cropping years, the effects of K and P effect gradually became more significant, and N, K became the main limiting factors, then there was no significant difference on the fresh storage root yield effect among N, P and K, there were equally important.

Aquilaria sinensis (Lour.) Gilg is a resin containing wood in the genus Aquilaria or Gyrinops. Among them, agarwood essential oil (AEO) is the main functional active component of agarwood, which has good neuroprotective effect and is often used to soothe the body and mind, relieve anxiety and depression, and treat insomnia. A large number of studies have shown that the chemical composition of AEO mainly includes chromones, sesquiterpenoids, aromatics, fatty acids and other compounds, among which 2-(2-phenethyl) chromone and sesquiterpenoids are the characteristic components. However, there is no clear standard for AEO classification and quality testing, and the quality of AEO is uneven, which greatly affects the development of agarwood industry. The efficacy of AEO is closely related to its chemical composition. The chemical composition and content of AEO obtained from different raw materials (species, origin, induction methods and time) and different extraction methods (hydro-distillation, supercritical fluid carbon dioxide extraction, solvent extraction) are quite different. Therefore, it will be the direction of future research to establish a sound grading and quality testing standard of AEO, and reveal the internal relationships of the chemical composition of AEO with the raw materials and extraction methods. In addition, due to the increasing demand for agarwood, the wild population of agarwood species has declined rapidly, resulting in the depletion of wild resources. However, with the popularization of artificial cultivation and induction methods, the yield of agarwood has been greatly improved, which provides a research basis for further research on AEO. This article reviews the chemical components of AEO from different sources and their application prospects in neuroprotective effects, and analyzes the problems existing in the current research of AEO.

A genus, Tolypanthus, and three species: Tolypanthus esquirolii (Lévl.) Lauener, Morus liboensis S. S. Chang and Scutellaria franchetiana Levl. from Fuyuan Shibalianshan Provincial Nature Reserve were reported as newly recorded species to Yunnan province. Voucher specimens for the reported species were preserved in the Herbarium of Kunming Institute of Botany (KUN), Chinese Academy of Sciences.

AT-hook nuclear localized proteins (AHLs) are small DNA-binding protein motifs that play an important role in plant growth and development, organ construction, stress and hormone signaling response. In this study, MeAHL17 was cloned from cassava cultivar SC8. Bioinformatics methods were used to analyze MeAHL17 promoter, protein physicochemical properties, prediction of conserved functional domain and sequence comparison. The results showed that the open reading frame length of MeAHL17 gene was 939 bp, encoding a protein with 312 amino acids, its theoretical isoelectric point was 6.89, its molecular formula was C₁₄₂₀H₂₂₁₅N₄₁₅O₄₅₁S₁₁, and its molecular weight was 32.669 38 kDa. The total number of positively charged amino acid residues (Lys+Arg) was 23, the total number of negatively charged amino acid residues (Asp+Glu) was 24, the fat coefficient was 57.47, the total average hydrophilic coefficient (GRAVY) was -0.491 and the instability coefficient was 58.06. The protein contains no signal peptide, is located in the cell membrane, has no transmembrane structure, contains 5 glycosylation sites and 45 phosphorylation sites, and is an unstable hydrophilic acidic protein MeAHL17 contained AT-hook conserved core sequences and PPC domain conserved core sequences, which was consistent with the typical structural characteristics of AT-hook family. Through subcellular localization and transcriptional activity analysis experiments, MeAHL17 was proved to be a nucleus localized transcription factor with transcriptional activity. Tissue expression pattern analysis showed that MeAHL17 was mainly expressed in somatic embryo, fibrous root and callus. Different hormone treatments showed that MeAHL17 was induced by ethylene (ACC), methyl jasmonate (JA) and growth hormone (IAA), which suggested that MeAHL17 might be involved in ethylene, methyl jasmonate and growth hormone signaling pathway. Abiotic stress treatment showed that MeAHL17 was responsive to drought and salt stress. This study preliminarily identified the important role of MeAHL17 in growth and development, hormone signaling and stress, and provided theoretical basis and reference for further study of its function.