Rubber tree is important in global rubber production. In order to reveal the effects of microelement fertilizer combined with absorption enhancer on the growth of rubber tree seedlings, and lay a foundation for the innovation of microelement fertilizer application technology of rubber tree. In this study, the single application of microelement (W), the combination of absorption enhancer formula 1 and microelement fertilizer (C₁+W), and the combination of absorption enhancer formula 1 and microelement fertilizer (C₂+W) were treated with ultra-pure water as the control to investigate the effects of compound microelement fertilizer application alone or combined with absorption enhancer on the growth, dry matter accumulation, photosynthesis, root development and nitrogen distribution of rubber tree seedlings and their mechanisms. The results showed that micronutrient fertilizer could increase the dry matter accumulation of roots, stems, and leaves in rubber seedlings, thereby increasing the individual fresh weight, dry weight, and dry to fresh ratio. Among them, C₂+W increased the fresh and dry weight of plants by 4.18 and 5.89 times, which is much greater than those of C₁+W and W. The accumulation of dry matter in rubber seedlings by microelements fertilizers was positively correlated with root length, root surface area, and root volume, and with chlorophyll content, transpiration rate, and net photosynthetic rate of rubber seedlings. The root development and photosynthesis were positively correlated with nitrogen accumulation in various organs of crops, soluble protein content, nitrate reductase activity (NR), glutamine synthase activity (GS), and glutamate dehydrogenase activity (GDH) in leaves. Notably, the single application of microelements fertilizer had no significant effect on NR activity, indicating that W had a weak effect on nitrogen assimilation in the reduction of nitric acid to nitrite. Significantly, the single application of microelements fertilizer (W) had no significant effect on NR activity, indicating that microelements fertilizer had a weak effect on nitrogen assimilation in the reduction of nitric acid to nitrite. In summary, microelements fertilizers and absorption enhancer enhance the connection between C assimilation and N metabolism processes in rubber seedlings, promote the growth and development of rubber seedlings. Considering the wide and thick leaves of rubber, tight cells, and thick stratum corneum, subsequent research should continue to screen more suitable absorption enhancer and optimize the combination with microelements.

As an important component of terrestrial soil carbon reservoirs, the agricultural soil organic carbon pool is greatly influenced by cultivation patterns. Coffee, one of the major economic crops in tropical regions of the world, a minor changes of its cultivation pattern can significantly affect the carbon balance of terrestrial ecosystems. Mulching cultivation is one of the traditional cultivation models for coffee, but its impact on the organic carbon composition of coffee plantation soil is still unclear. Therefore, based on the previous research of our team using coffee peel and leaf litter as substitutes for traditional mulch to cultivate coffee, four mulching treatments were set up in this study: uncovered coffee waste (CK), coffee leaf litter mulch (L), coffee peel mulch (P), and both coffee peel and litter mulch (PL). Soil micro-environment, microbial community diversity and biomass, organic carbon fractions, and other indicators were monitored in the coffee plantation, and the intrinsic relationships between soil micro-environment, microbial community structure, and organic carbon fractions were analyzed to investigate the effects of coffee waste cover on soil components and the key driving factors. The results showed that coffee waste cover did not affect the content of soil organic carbon (SOC), heavy fraction organic carbon (HFOC), and dissolved organic carbon (DOC), while coffee peel and litter mulch significantly increased the content of soil light fraction organic carbon (LFOC) by 13.31% and 14.12%, respectively. Coffee waste mulch did not affect soil micro-environment indicators or microbial diversity. Coffee peel cover significantly increased soil microbial biomass by 14.05%, and increased the relative abundance of Proteobacteria and Firmicutes by 18.60% and 80.77%, respectively, while reducing the abundance of Cyanobacteria by 70.14%, but had little impact on soil fungal community. Coffee litter mulch significantly increased the relative abundance of Proteobacteria and Firmicutes by 14.43% and 57.63%, respectively, while reduced the abundance of Cyanobacteria by 73.43%, and significantly increased the relative abundance of dominant fungi Ascomycota by 14.79%. The reason why coffee waste mulch did not affect the soil organic carbon content is mainly attributable to the insensitivity response of HFOC content to coffee waste mulching. The increase of microbial biomass and the increase relative abundance of Firmicutes are the main reasons to enhance the excitation effect caused by external organic carbon input, thus significantly increasing the content of soil LFOC content. The short-term mulch of coffee waste significantly increased the content of soil LFOC content, which is contribute to improve the soil carbon storage of coffee plantations and optimize the green and low-carbon production mode of coffee.

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.

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.

In order to investigate the effects of intercropping Centrosema pubescens or Grona styracifolia on soil physicochemical properties, microbial community structure and diversity in the litchi orchard, soil samples from 0 to 40 cm depth between litchi tree rows were collected under intercropping with either C. pubescens or G. styracifolia. Physicochemical factors such as soil organic matter, total nitrogen, total phosphorus, total potassium, nitrate nitrogen, ammonium nitrogen, available phosphorus, available potassium and pH were measured. In addition, Illumina NovaSeq sequencing platform was used for 16S amplicon sequencing to analyze the microbial communities in the soil under intercropping with C. pubescens or G. styracifolia in the litchi orchard. The results showed that the nutrient content in the 0-20 cm soil layer was generally higher than that in the 20-40 cm soil layer. In the 0-20 cm soil layer, the C. pubescens intercropping treatment increased soil organic matter by 7.06%, total nitrogen by 8.70%, and ammonium nitrogen by 103.29%, compared to the control. In the intercropping treatment with G. styracifolia, soil ammonium nitrogen increased by 69.41%, nitrate nitrogen increased by 32.48%, available phosphorus increased by 112.78%, and available potassium increased by 9.44%, compared to the control. In the 20-40 cm soil layer, the C. pubescens intercropping treatment increased soil ammonium nitrogen by 114.58%, but decreased available potassium by 48.07%, compared to the control. In the intercropping treatment with G. styracifolia, soil nitrate nitrogen decreased by 15.07%, while available phosphorus increased by 105.43% and available potassium increased by 32.60%, compared to the control. In terms of microbial diversity, the indices in the 0-20 cm soil layer were generally higher than those in the 20-40 cm soil layer. In the 0-20 cm soil layer, the ACE index and Chao1 index in the C. pubescens intercropping treatment were decreased by 7.65% and 7.68%, respectively, compared to the control. In the 20-40 cm soil layer, the ACE index and Chao1 index in the intercropping treatment with G. styracifolia were increased by 6.93% and 6.74%, respectively, compared to the control. In terms of soil microbial community structure, the dominant phyla in all soil samples were Acidobacteria, Chloroflexi, Proteobacteria, Firmicutes, and Actinobacteria, while the dominant genera were Gp2, Gp13, Bryobacter, Candidatus Solibacter and Bathyarchaeia within the Acidobacteria phylum. After intercropping, the relative abundance of Thaumarchaeota, Nitrospirae, Verrucomicrobia, Gp2, Gp13 and Bryobacter increased. Redundancy analysis indicated that pH, total potassium, total phosphorus, and available potassium were the main physicochemical factors affecting soil microbial community structure. In summary, the results of this study would provide a theoretical basis for intercropping with C. pubescens or G. styracifolia in litchi orchards.

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.

Passion fruit (Passiflora edulis) is a characteristic and advantageous fruit in Guizhou, which is of great significance in poverty relief consolidation and the rural revitalization. However, in recent years, the viral diseases of passion fruit have become increasingly severe, leading to a sharp decline in yield and quality, which thereby seriously constrain industry development of passion fruit. In order to determine the virus species, distribution and compound infestation in the main plantation areas of passion fruit in Guizhou province, a total of 153 samples suspectedly infected by virus were collected from five main plantation orchards of passion fruit in five counties, i.e. Luodian, Congjiang, Rongjiang, Zhenning and Zhenfeng, and the virus detection was carried out by RT-PCR. The results showed that seven viruses were detected from the tested samples, namely East Asian Passiflora virus (EAPV), Telosma mosaic virus (TeMV), Cucumber mosaic virus (CMV), Turnip mosaic virus (TuMV), Passiflora mottle virus (PaMV), Passiflora latene carlavirus (PLV), and Potato virus Y (PVY), among which PVY infection was firstly reported from passion fruit. EAPV was the most prevalent one with infection rate as high as 96.08%, followed consecutively by TeMV (81.70%), CMV (78.43%), TuMV (44.44%), PaMV (26.80%), PVY (24.84%) and PLV (15.03%). In the present case, the distribution of passion fruit viruses in Guizhou province and the diversity of virus sequences were analyzed. Seven viruses were detected in Zhenning, six in Zhenfeng, five in Rongjiang and Congjiang, and three in Luodian. There’s a close identity between the nucleic acid of the seven detected viruses and the corresponding reference sequences (above 95%). Phylogenetic analysis revealed that EAPV, TeMV, PaMV, PLV and TuMV somewhat geographical clustered with passion fruit virus isolated from other provinces in China. CMV and PVY were most closely related to Cucumis melo CMV isolated from Spain and Capsicum annuum PVY isolated from Rwanda respectively, suggesting that the virus sequences diversely varies among the origins in China. A total of 24 types of mixed infection were detected in the main growing areas of passion fruit in Guizhou, and the complex infection rate was as high as 94.77%. The complex infection with 3-5 types predominated in the tested samples, and the combination of EAPV+TeMV+CMV was most frequent among the complex infections among which, EAPV, TeMV and CMV detected ranged from 78.43% to 96.08% in the five counties, somehow reflecting that they were the major viruses to prevent in passion fruit industry of Guizhou province. In addition, a multiplex PCR assay system for EAPV, TeMV and CMV was established in this study, which provides technical support for the rapid detection of related viruses.

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.

Cassava mosaic disease (CMD) poses a serious threat and danger to cassava production in China and the world, and there is no effective control method and lack of resistant materials, causing serious economic losses, and is considered one of the most threatening viral diseases. Sri Lankan cassava mosaic virus (SLCMV) is one of the major pathogens causing cassava mosaic disease. RNA silencing is an innate antiviral immune response mechanism in plants and animals, and post transcriptional gene silencing (PTGS) is a conserved gene expression regulatory mechanism in eukaryotes, and is one of the important antiviral immune mechanisms. Suppressor of gene silencing 3 (SGS3) is a key protein of the PTGS pathway and plays a critical role in host defense against viral invasion. To counteract this host immune response, viruses usually encode viral suppressors of RNA silencing (VSRs) to counteract the viral defense mechanism of host PTGS, and interaction with host proteins is one of the main mechanisms of action for the silencing suppressors to function. In order to investigate whether SLCMV AC2 inhibits the immune function of host PTGS by interacting with AtSGS3, we analyzed the immune function of host PTGS by using yeast two-hybrid (Y2H) system and bimolecular fluorescence complementation (BiFC) experiments, to analyze the interaction between AtSGS3 and SLCMV AC2. The results showed that SLCMV AC2 interacted with AtSGS3 protein in both yeast cells and plants. In subcellular co-localization experimental studies, we further demonstrated that SLCMV AC2 could co-localize with AtRDR6, a close partner of AtSGS3, after interacting with AtSGS3. The data suggest that SLCMV AC2 may affect the host autoimmune mechanism and enhance viral pathogenicity by interacting with siRNA-body, and that the interaction between SLCMV AC2 and AtSGS3 may be the molecular basis for the development of foliar symptoms in SLCMV-infected cassava, and the results of this study would provide a new theoretical basis for the subsequent in-depth analysis of the pathogenicity mechanism of SLCMV.

Powdery mildew caused by Erysiphe quercicola is a significant disease in China’s natural rubber industry, posing a severe threat to latex production. With the continuous advancement of predictive and forecasting technologies, the combination of qPCR detection and spore capture techniques holds promise as an efficient method for predicting the prevalence of powdery mildew. In this study, we focused on the microscale extraction of DNA from rubber tree powdery mildew spores. We compared various pre-treatment methods, different types of grinding beads with varying materials, and different types of grinding machines to identify the most suitable spore sample grinding system. Furthermore, we compared the efficiency of the CTAB method with several commercial extraction kits. Ultimately, we established a feasible microscale DNA extraction method for spores: first, the powdery mildew spore water solution subjected to 4 ℃ultrasonication for 10 min, subsequently, 2 mm zirconia beads (0.2 g), glass beads (0.4-0.6 mm, 0.2 g), and 0.2 mm zirconia beads (0.2 g) added, tissue grinder 70 Hz at 4 ℃, grind 40 s, stop 10 s, 20 cycles, finally, DNA extracted using the CTAB method. This method effectively and stably extracts DNA from 10¹ spores/mL rubber tree powdery mildew spores, without being affected by complex field conditions, and demonstrates high sensitivity and specificity. It provides a reliable theoretical basis and an effective technical approach for the prediction and forecasting of rubber tree powdery mildew.