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.

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.

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.

The purpose of this study was to provide a scientific basis for the classification, breed selection and targeted development and utilization of different germplasm of Aquilaria sinensis. The samples of agarwood from six different germplasms were studied: Aquilaria sinensis ‘Haixiang 1’, A. sinensis ‘Haixiang 2’, A. sinensis ‘Haixiang 3’, Piyou type, Big leaf type and Nangpao type. Gas chromatography-mass spectrometry (GC-MS) was used to study the composition of the agarwood samples extracted by ultrasonic ether method. The volatile components of agarwood produced by the above six germplasms were higher in sesquiterpenoids and lower in chromones, The volatile components of six germplasms were quite different, except two components in common, namely butylated hydroxytoluene and 2,2'-methylenebis[6-(1,1-dimethylethyl)-4-methyl-phenol]. The number of sesquiterpenoids (10-26 kinds) and the total relative percentage content (25.39%-87.50%) were higher, and the main component was baimuxinal, among which A. sinensis ‘Haixiang 3’ had the highest amount and content. The quantity (1-3 species) and total relative percentage content (4.66%-37.32%) of chromones were low, mainly 2-(2-phenylethyl) chromones, among which A. sinensis ‘Haixiang 1’had the highest quantity and content, while A. sinensis ‘Haixiang 3’, Big leaf type and Nangpao type were not detected. The agarwood from A. sinensis ‘Haixiang 1’, A. sinensis ‘Haixiang 2’, A. sinensis ‘Haixiang 3’, Piyou type, had relatively rich aromatic components (baimuxinal,7α-H-9(10)-ene-11,12-epoxy-8-oxoeremophilane, karanone and so on). The agarwood produced by A. sinensis ‘Haixiang 2’, A. sinensis ‘Haixiang 3’, Piyou type and Nangpao type contained many sesquiterpenoids, such as agarospirol and (-) jinkoh-eremol. The content of benzylacetone in A. sinensis ‘Haixiang 1’, A. sinensis ‘Haixiang 2’ agarwood was high. 7α-H-9(10)-ene-11,12-epoxy-8-oxoeremophilane and 6,7-dimethoxy-2-(2-phenylethyl) chromone in the agarwood produced by A. sinensis ‘Haixiang 1’, A. sinensis ‘Haixiang 3’ and Big leaf type were high. The types and contents of volatile components of agarwood derived from the six different germplasms showed great difference, which could be developed according to the difference of active components.

Previously, we achieved gene editing using CRISPR/Cas9-RNP and plasmid in the PEG-mediated protoplasts transient transformation of rubber tree, and by targeting the HbPDS gene, callus with albino phenotype were obtained, but no edited plants were regenerated because the technology of embryogenesis from callus is not yet mature. In order to obtain gene edited seedlings, we used the same HbPDS target as previous in the callus editing, but used somatic embryos as the transformation receptor instead of callus. After hygromycin resistance screening, 116 positive T₀ generation embryos were selected through Cas9 gene PCR detection, following by next generation sequencing, five embryos were found to be edited at the target, accounting for 4.3% of PCR positive embryos. At last, two regenerated plants were obtained, both were chimeric because only partial albino leaves appeared in the plantlet. Sequencing of both albino and green parts revealed that gene editing had occurred in all samples, besides a homozygous biallelic mutation in one albino leaf, all other leaves exhibited chimeric mutations, with mutant sequences in albino parts accounting for 86% to 100% ratio, while green parts accounting for 66% to 69% ratio. This indicates that the mutation threshold inducing the expected phenotype in rubber tree CRISPR/Cas9 editing plants is higher than 69%, ranging from 70% to 85%, providing theoretical guidance for obtaining gene editing seedlings with expected phenotype in the future. Meanwhile, it is proven that nearly all the regenerated plantlets obtained from T₀ generation somatic embryos are chimeric, thus T₀ generation embryos are not suitable as regenerated materials, but also providing insights to improve the regeneration procedure by using T₁ embryo to get homozygous seedlings in the future. This is the first report about gene editing plants in rubber tree, although they are chimeric, it still enhances the understanding of the function of CRISPR/Cas9 in rubber tree, laying the foundation for improving and applying gene editing technology in rubber tree.

Paphiopedilum is one of the most valuable orchid groups with its unique shape, rich flower colors and long flowering period. The shape of the lip of Paphiopedilum is peculiar, and it is specialized as a pouch or helmet, it looks like a lady’s slippers, so it is also known as the slipper orchid. However, due to the low seed germination rate of Paphiopedilum, low propagation rate of traditional division propagation, immature tissue culture propagation technology, and relatively difficult to cultivate, it is difficult to meet the market demand through artificial breeding. Resulting in the serious exploitation of wild resources and the destruction of its living environment, wild resources continue to decrease, Paphiopedilum is now one of the most endangered species in the world. In this paper, the geographical distribution and habitat of Paphiopedilum in the world and China were analyzed by means of literature retrieval, with special attention to the new species published in recent years, which can provide reference for the conservation and utilization of wild Paphiopedilum germplasm resources. Understanding the geographical distribution characteristics of Paphiopedilum is of great significance for in situ and ex situ conservation of Paphiopedilum germplasm resources. At present, there are about 109 species and 26 varieties of Paphiopedilum in the world. Since the English edition of the Flora of China in 2009, 7 new species of Paphiopedilum have been discovered in China, on the basis of the original 27 species of Paphiopedilum, and 30 new species have been discovered in the world during this period. Paphiopedilum mostly distributed in tropical and subtropical transition areas, originated in southwest China and Southeast Asia, and then spread to Southeast Asian islands, Indonesia (Sulawesi, Java etc.) and China (Yunnan, Guangxi etc.) are the distribution centers of Paphiopedilum. The main factors affecting the distribution of Paphiopedilum are climate, topography, soil, symbiotic microorganisms, pollinators and so on. The distribution pattern of Paphiopedilum is influenced by both large scale (climate factor) and small scale (small habitat, such as landform, soil, etc.). Paphiopedilum may gradually spread and migrate to areas within its temperature tolerance range. In the past 50 years, the high latitude area has warmed more, and the suitable area for the growth of Paphiopedilum has expanded, resulting in its distribution range spreading or migrating to high latitudes and high altitudes. The seasonal temperature changes may cause the distribution of Paphiopedilum plants (Paph. subgenus Brachypetalum) to shift to higher or lower latitudes. The phenology, morphology and genes of Paphiopedilum plants may also undergo certain changes, and the number of species that do not adapt to environmental changes will gradually decrease until extinction, and new species will continue to emerge. The distribution of Paphiopedilum is also affected by topography, soil physical and chemical properties, soil microorganisms and other factors. Microorganisms in soil, especially fungi, can promote the germination of Paphiopedilum seeds. If fungi that are mutually beneficial to Paphiopedilum are lacking in the new habitat, the seeds of Paphiopedilum may not germinate smoothly, and the population of Paphiopedilum may be restricted to a specific area. The distribution of Paphiopedilum is also closely related to pollinators, and the species, quantity and distribution of pollinators affect the distribution pattern of the corresponding Paphiopedilum. Pollinating insects of Paphiopedilum are abundant, mainly belonging to the family of Syrphidae, and insects of Apidae, Halictidae, Colletidae and Megachilidae can also be used as pollinators for Paphiopedilum. There is usually more than one effective pollinator of each Paphiopedilum species. The study on the geographical distribution pattern of Paphiopedilum would provide reliable evidence for the species evolution between genera and within genera. The more primitive Paphiopedilum was mostly terrestrial, while the more evolved Paphiopedilum evolve into semi-epiphytic or epiphytic orchids due to environmental adaptation and competitive pressure, growing on cliffs or between rocks.

Tigernut (Cyperus esculentus L.), most likely originated from Africa and Mediterranean, represents a novel herbaceous oil crop accumulating high levels of oil in its underground tubers. Water balance is essential for tuber development and metabolism in tigernut. Tonoplast intrinsic proteins (TIPs), which include five phylogenetic groups (i.e. TIP1–5), constitute a subfamily of aquaporin facilitating the fast and passive transport of water across vacuolar membranes. Based on available genome and transcriptome data, one TIP gene named CeTIP2;1 was isolated from tigernut tubers by using the RT-PCR technique. Sequence analysis showed that the full gene length of CeTIP2;1 is 3323 bp, including two introns with a coding sequence of 747 bp; the gene was predicted to encode 248 amino acids with the theoretical molecular weight of 24.73 kDa, the isoelectric point of 5.09, the grand average of hydropathicity of 0.948, the aliphatic index of 114.60, and the instability index of 21.76, implying its stable, acidic, and hydrophobic features, which is consistent with its tonoplast-localization; presence of one conservative MIP domain was observed, which possesses six transmembrane helices, two half helices, and two typical NPA motifs. CeTIP2;1 was shown to exhibit the sequence similarity of 87.20% with AtTIP2;1, which was considerably higher than 46.23% with SoPIP2;1. Further phylogenetic analysis revealed that CeTIP2;1 belongs to the TIP2 group and is a true ortholog of AtTIP2;1. Interestingly, the phylogenetic analysis also supported that TIP2 has diverged into two subgroups sometime before monocot-eudicot divergence. Tissue-specific expression analysis showed that CeTIP2;1 was highly expressed in all tissues examined in this study, i.e., leaf, sheath, root, shoot apex, rhizome, and tuber, with most in tuber/rhizome and lowest in shoot apex. A bell-like expression pattern was observed during tuber development, peaking at the medium stage of swelling and lowest in maturation. Moreover, CeTIP2;1 was also detected in the tuber proteomes, implying its high abundance and key roles. These findings would lay a solid foundation for further uncovering the mechanism of water balance in tigernut tubers.

Choline monooxygenase (CMO) is a key enzyme in the synthesis of betaine in higher plants and plays an important role in the physiological process of plant resistance to stress. A CMO gene was identified in banana A and B reference genomes in banana gene database, and the biological information analysis of MaCMO and MbCMO genome sequences showed that MbCMO might be formed by a gene encoding a banana O-fucosyltransferase family protein and MbCMO gene in tandem. The CMO gene coding sequences of Zhanjiang AA (ZJ; AA genotype), Baxijiao (BX; AAA genotype), Guangdong Dajiao (GD; AAB genotype) and Jinfen (JF; ABB genotype) were cloned and compared, it was found that ZJ and BX only contained CMO-A, GD and JF both contained CMO-A, CMO-B1 and CMO-B2, and JF also contained CMO-H. Codon usage characteristics showed that there were 23 common high frequency codons among the four banana CMO gene, and the codons CUU and CCG were the most biased and the weakest codons, respectively. The physicochemical properties of CMO-A protein and CMO-H protein showed that the minimum number of amino acids was 425, the maximum number of amino acids was 470, and the secondary structure of CMO-B1 protein was the most complex. The molecular weight of CMO-B2 protein was 52.02 kDa, and the molecular weight of CMO-A protein was 47.48 kDa. All the four CMO proteins were acidic proteins, which did not have a transmembrane structure and were hydrophilic proteins. Subcellular localization prediction showed that all four CMO were localized in chloroplasts. In terms of evolution, plant CMO had obvious branches in monodicotyledonous plants during evolution, and the CMO-A, CMO-H, CMO-B1 and CMO-B2 proteins of banana were more closely related to other monocotyledonous plant CMO proteins. The results of RT-qPCR showed that CMO expression was up-regulated in the four kinds of banana roots in the early stage of osmotic stress, and the expression levels of ZJ and BX CMO in homozygous A genome were higher than those of GD and JF CMO in heterozygous A and B genomes. CMO expression in the four kinds of banana leaves was down-regulated at the early stage of osmotic stress. The expression levels of homozygous ZJ and BX CMO in A genome were up-regulated at the late stage of osmotic stress, while the expression levels of heterozygous GD and JF CMO in A and B genomes peaked at 10 days and then down-regulated again at 15 days later. It was significantly lower than that of ZJ and BX CMO. This study revealed the differences of CMO genes between the A and B genomes of bananas and the expression patterns of CMO genes in different genotypes of bananas under osmotic stress, which would lay a foundation for further research on the biological functions of CMO genes in the A and B genomes of bananas, especially the relationship between CMO genes derived from different genomes and the ability of banana to resist osmotic stress. It would provide a reference for improving the stress resistance of banana by genetic engineering.

In order to find out the ratio of silicon and calcium fertilizer suitable for the cultivation of passion fruit in the low-heat valley area of Guizhou, this study took passion fruit Qinmi No. 9 as the test material. The experiment was conducted with 50 g of silicon fertilizer per plant before flowering, spraying calcium fertilizer about 10 days after flowering, spraying once every 15 days, spraying three times continuously, and the concentration of calcium fertilizer was 500 times, 1000 times and 1500 times. CK was used as the control group, which received no fertilizer application. The effects of different medium and micro fertilizers, as well as dosages, on the quality and related cell wall metabolism indexes of passion fruit were explored by applying silicon fertilizer to the soil and spraying calcium fertilizer during the flowering and fruiting periods. The aim was to screen for the best specialized silicon-calcium fertilizer formula. The aim is to provide a theoretical basis and practical guidance for improving the quality of passion fruit. The results showed that compared with the control, soil application of silicon fertilizer and spraying calcium fertilizer 1000 times combined application increased the single fruit weight, fruit hardness and fruit shape index of passion fruit. Additionally, they elevated the content of soluble solids (TSS) and vitamin C (Vc), while reducing the content of titratable acidity (TA). Furthermore, there was an increase in soluble sugar (SS) and soluble protein content (SP). Peroxidase (POD), superoxide dismutase (SOD), and catalase (CAT) activities were promoted. However, the activities of water-soluble pectin (WSP) content, cellulase (CX), polygalacturonase (PG), and pectin methylesterase (PME) decreased due to the increase in protopectin and cellulose in the peel, each index was significantly different from the control group. It shows that silicon-calcium fertilizer had the best effect on enhancing passion fruit quality and improving the mechanical strength, toughness and stability of peel. Compared to CK, the single fruit weight, fruit hardness, longitudinal diameter and transverse diameter increased by 11.15%, 27.18%, 6.23% and 3.29%, respectively. Moreover, the contents of TSS, Vc, SS and SP increased by 16.95%, 16.12%, 20.57% and 24.55%, respectively, while the content of TA decreased by 36.03%, and the activities of POD, SOD and CAT increased by 13.16%, 19.67% and 21.65%, respectively. The content of protopectin and cellulose in peel increased by 19.29% and 17.19%, respectively. Meanwhile, the content of WSP decreased by 10.63%, and the activities of CX, PG and PME decreased by 8.58%, 22.98% and 7.52%, respectively.

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.