Drought resistant microbial preparations are beneficial soil microorganisms that produce plant growth hormone to enhance the drought tolerance of plants and promote plant growth, which is an ideal substitute for traditional chemical drought resistant preparations. In this study, the bacteria obtained in the soils of Wuyishan tea plantation were used as the research object to screen strains with the high secretion indole-3-acetic acid (IAA) ability and strong drought resistance, and the culture conditions optimization and whole genome sequencing analysis were also conducted. A strain SZF7 with high secreting IAA was obtained, which belonged to Bacillus cereus, which had stronger drought resistance than other strains. The optimal culture conditions for IAA secretion of SZF7 were pH 5.0 and 37 ℃ with 24 h incubation, and pH and temperature significantly affected on the IAA secretion. In the COG and KEGG metabolic pathways of SZF7 genome, the genes related to biological metabolism accounted for 47.96% and 68.52% of the total functional genes, respectively. The genes related to plant growth promotion included IAA, siderophore, non-ribosomal peptide synthase (NRPS), lipopeptide compounds and bacillibactin. There were two IAA synthesis pathways in SZF7, one of which was indole-3-pyruvate pathway mediated by indole-3-pyruvate decarboxylase, and the other was tryptamine pathway mediated by indole-3-glycerol phosphate synthase. This study would provide a scientific basis for the application of drought-resistant and growth-promoting bacteria in the production of tea and other cash crops.

Sweet potato is often base fertilized with nitrogen and no further dressing nitrogen fertilizer is needed. It is important to develop and screen slow-releasing nitrogen fertilizers that could meet the nitrogen requirements of sweet potato at different growth stages in order to promote yield and reduce nitrogen rate. A greenhouse pot experiment using variety Sushu 16 was conducted to analyze the effects of different slow-releasing nitrogen fertilizers (urea formaldehyde, sulfur-coated urea, urea formaldehyde resin, urea combined with nitrification inhibitors) on leaf photosynthesis, above-ground and underground biomass and nitrogen content, nitrogen use efficiency, and soil mineral nitrogen (nitrate nitrogen and ammonium nitrogen) content at different growth stages of sweet potato (seedling stage, vine burying stage, bulking stage, and harvest stage). Compared with the control, the sulfur-coated urea and oxamide controlled-release nitrogen fertilizers increased the biomass of sweet potato roots by 96.79% and 103.59%, respectively, significantly higher than that of the urea-formaldehyde and urea combined with nitrification inhibitor treatments (P<0.05). In addition, the photosynthesis rate of sweet potato throughout the entire growth period was significantly higher in the sulfur-coated urea treatment than that of unfertilized control, which is beneficial to improving the biomass of sweet potato roots. The nitrogen releasing of sulfur-coated urea and oxamide was less in the seedling and closure period and more in the swelling period and harvest period. The sum of ammonium nitrogen and nitrate nitrogen was 1.24-1.60 times that of urea-formaldehyde and urea combined with nitrification inhibitor, and the nitrogen fertilizer utilization rate increased by 1.17-1.80 times. In conclusion, sulfur-coated urea and urea formaldehyde are more suitable for the one-time application of nitrogen fertilizer in sweet potato production. The study results could provide scientific basis for nutrient management and nitrogen fertilizer reduction and yield enhancement in sweet potato production.

SOC1 (SUPPRESSOR OF OVEREXPRESSION OF CONSTANS 1) is a flowering time regulator in plants. It belongs to the MADS-box transcription factor family and plays a crucial role in the transition from vegetative to reproductive growth in plants. SOC1 is involved in various biological processes, including flower organ development, flowering time control, and response to environmental stimuli and hormone signals. In this study, shading and application of Lorsben were used for flower induction in wax apple, and the number of leaf buds, flowers, and the rate of flowering shoots were recorded after treatment. Additionally, the existing transcriptome data of wax apple in our research group were analyzed to identify the candidate gene SsSOC1 involved in regulating flowering in wax apple. The differential expression of SsSOC1 in different stages and tissues of wax apple under shading and Lorsben treatment was studied using qPCR. The results showed that the expression of the SsSOC1 gene significantly increased in the buds, leaves, leaf tips, and petioles of wax apple treated with shading, with the highest relative expression in the leaf tips. In this study, the SsSOC1 gene from Hei Tang Ba Bi wax apple was successfully cloned, and its promoter analysis, physicochemical properties of the protein, prediction of conserved functional domains, and sequence alignment were performed using bioinformatics methods. The open reading frame of the SsSOC1 gene in wax apple was found to be 654 bp, encoding a protein of 217 amino acids. The theoretical isoelectric point of the protein was 9.37, with a molecular formula of C₁₀₇₆H₁₇₉₄N₃₂₂O₃₃₄S₁₀ and a molecular weight of 24.91 kDa. The protein contained 40 positively charged amino acid residues (Lys+Arg) and 32 negatively charged amino acid residues (Asp+Glu). The protein had a fat coefficient of 80.64, a grand average of hydropathicity (GRAVY) of -0.729, and an instability coefficient of 66.17. The protein structure lacked β-folds and did not belong to secretory or membrane proteins. Subcellular localization analysis indicated that the protein was mainly present in the nucleus and belonged to an unstable hydrophilic basic protein. The SsSOC1 protein in wax apple possessed conserved domains including MADS_MEF2_like and K-Box and belonged to the MADS superfamily and K-Box superfamily. The analysis identified the amino acid positions 3 to 75 and 88 to 171 as the start and end sites of the conserved domains, respectively, conforming to the typical structural features of the MADS protein family and the K-Box family. The evolutionary tree showed the highest homology between the SsSOC1 sequence in wax apple and Syzygium oleosum. By floral dip transformation, the SsSOC1 gene was introduced into Arabidopsis, and it was found that the 35S::SsSOC1 line exhibited an early flowering phenotype and a reduced number of rosette leaves compared to the wild type. This study preliminarily elucidated the important role of the SsSOC1 gene in flowering in wax apple and attempted to reveal the intrinsic regulatory mechanism of shading-induced flowering, providing guidance for wax apple production and theoretical basis for improving out-of-season cultivation techniques.

The study was aimed to investigate the soil-microbial carbon, nitrogen and phosphorus characteristics of Eucalyptus plantations at different altitude gradients in Hainan Tropical Rainforest National Park. Typical Eucalyptus plantation forests at different altitudes (500 m, 700 m and 900 m) in Wuzhishan were used as the study object, and natural secondary forests at the same altitude were used as the control. Soil organic carbon (SOC) and total nitrogen (TN) content showed a gradual increase with elevation, and total phosphorus (TP) showed a gradual decrease. The range of variation was 13.16-13.58, 0.93-1.15, 0.17-0.19 g/kg, respectively, which was lower than the SOC and TN contents of natural secondary forests, and lower than the national average values of SOC, TN and TP contents of forests. The microbial biomass carbon (MBC) and microbial biomass nitrogen (MBN) showed a trend of gradual increase with elevation, and the microbial biomass phosphorus (MBP) content overall showed a decreasing trend with elevation, with the range of 237.46-398.26, 23.04-30.74, 4.77-9.59 mg/kg, respectively, and with the TP contents. TP showed highly significant positive correlation (P<0.01). The differences were not significant compared with those of natural secondary forests at the same elevation. MBC/MBN, MBC/MBP and MBN/MBP all tended to increase with elevation, with ratios ranging from 9.05-13.17, 24.73-80.99 and 2.76-6.60. At 500 m, the MBC/MBP and MBN/MBP of the Eucalyptus plantation were significantly different from those of the natural secondary forest.. The variation of microbial quotient carbon (qMBC), microbial quotient nitrogen (qMBN) and microbial quotient phosphorus (qMBP) at different elevations was 1.89%-3.34%,2.90%-3.23% and 1.33%-5.41%, respectively. qMBC showed a gradual increase in elevation, and qMBP declined with the elevation. qMBC and qMBP were higher than those of natural secondary forests. qMBC and qMBP were higher than those of natural secondary forests. Soil organic carbon and total nitrogen were the key factors affecting the changes. In conclusion, the elevation gradient has a significant impact on the content and stoichiometric ratio of soil-microbial carbon, nitrogen, and phosphorus in Eucalyptus plantations. Compared with natural secondary forests at the same elevation, the soil of Eucalyptus plantations exhibited a deficiency in carbon and phosphorus contents, but enhanced the conversion efficiency of soil carbon and phosphorus to microbial biomass carbon and phosphorus. Based on this, the Eucalyptus plantations in the park should be conserved, and attention should be paid to the influence of carbon and phosphorus elements in the subsequent management.

The study was aimed to breed new coffee varieties with good characteristics for improving the yield and quality of Yunnan coffee production. Arabica coffee hybrid F₁ was introduced from Nestle R&D Center in France to Pu’er to study plant growth, fruiting characteristics, yield and bean physical properties. The varieties are 107, 117, 118,120, 121, 10×25 and 12×25, and the control is T8667, a widely planted cultivar. The test sites were Simao, Ning’er, Menglian and Jiangcheng. The results indicated that the plant height, stem diameter and crown width of the 3-year-old plant for the varieties was 84.20-175.00 cm, 21.69-53.34 mm, and 74.80-165.30 cm, respectively. All test varieties were dwarf plant. GPFA117 showed thicker stems and wider crown, 118 and 121 had better crown width than the control. The number of primary branches was 34.00~62.20. The longest primary branch length and diameter range was 43.40-89.00 cm, 4.86-11.40 mm respectively. The varieties with excellent performance were those with more number of primary branches, strong and long branches. 117, 118 and 121. 10×25 showed longer primary branches than the control, and the primary branch of 107, 120 varieties was thicker and longer, which can also be used as a good trait in future breeding. The least number fruits per node were 12×25 and T8667, and other varieties had more than 15 fruits per node. The variety 107, 117, 118, 120, 121 and 10×25 had the highest fresh fruit yield per plant and dry bean yield per hectare, up to 4.50–6.58 kg and 3289.46–4968.57 kg. Varieties 117, 118 and 120 had an average dry bean yield of over 3000 kg/hm² during the two-year peak production period, indicating a relatively high level of yield. It showed the advantage of high yield of hybrid varieties respectively. The fresh-dry ratio was (4.31-6.48)∶1, the highest was 10×25. The weight of 100 parchment beans was 14.93-20.67 g, and that of 12×25 was the smallest one. Others showed completely filled fruit and medium bean granularity. Varieties 117, 118, 120, 121 and 10×25 had some excellent traits such as plants shorter, thicker stems, wider crown, more thicker and longer primary branches, high yield, plump fruits, medium grain size over T8667. The varieties would provide scientific basis for promoting high-yield and high-quality coffee varieties in production.

Date palm is hermaphroditic and highly heterogeneous in genetics, resulting in severe phenotypic variation. Propagation of seedlings depends on asexual reproduction, and tissue culture technology is the main means of commercializing date seedling production at present. However, the difficulty in inducing embryogenesis and the long induction cycle lead to difficulties in system construction and high tissue culture costs. Therefore, it is urgent to study the effects of hormone regulation on the endogenous metabolic substances of date embryos and optimize the embryogenesis system. This study is based on the selection of date explants, induction of callus and embryogenic callus in the previous studies, and uses orthogonal experimental design to screen and match the plant growth regulators and concentrations in the MS culture medium to induce embryogenesis from callus. The study statistically recorded the embryogenesis rate, induction cycle, and survival rate; date embryos with different levels of hormone were sampled; the morphological changes of date embryos in a regular manner were observed; and the changes in the content of total protein (Cpr), soluble sugar (WSS), catalase (CAT), glutathione reductase (GR), amino acids (AA), auxin, cytokinin (CTK), abscisic acid (ABA), and gibberellin (GA) were measured. The results showed that the embryogenic rate of C₉ was higher than that of C₅, C₄, C₆, and the time for embryogenesis was the shortest in the C₅ treatment. In the C₉ treatment, the highest content of catalase and amino acids was found in the embryos, and the highest protein content was found in the C₅ treatment. The coefficient of variation was the largest for glutathione reductase content, and the maximum difference was found in amino acid content. The correlation analysis showed that thiocyanate and gibberellin had the strongest correlation with glutathione reductase, and soluble sugar had the strongest correlation with protein and amino acid. Principal component analysis showed that the first four principal components accounted for 88.714% of the total variance, with an eigenvalue of 3.877 for the first principal component, a contribution rate of 43.076%, and the first principal component was mainly influenced by thiocyanate content, soluble sugar content, protein content, and gibberellin content, with the highest eigenvalue of 0.921 for thiocyanate content, reflecting the impact of thiocyanate on embryogenesis. The study would provide theoretical support for optimizing the embryogenesis system and laying a technical foundation for achieving efficient and rapid propagation of date palm.

The aim of this study was to screen out insecticides that exhibit higher toxicity to Ferrisia virgata, thereby establishing a scientific foundation for controlling F. virgata. The toxicity of 14 insecticides on F. virgata was assessed indoors at 6 h, 12 h, 24 h and 48 h after application by a spraying method, among which the median lethal concentration (LC₅₀) values of the 7 insecticides showing greater efficacy against the 3rd nymph F. virgata were determined specifically at 24 h and 48 h post-application. Based on the recommended dosage of each insecticide, the field control efficacy of acetamiprid, sulfoxaflor, fenpropathrin, diazinon, thiamethoxam, profenofos·lufenuron, flonicamid·bifenthrin against F. virgata was evaluated by artificial spraying in the areca field of Yazhou, Sanya, Hainan in May 2024. The preliminary screening results showed that acetamiprid, sulfoxaflor, fenpropathrin, diazinon, thiamethoxam, profenofos·lufenuron, flonicamid·bifenthrin had good toxicity against the 3rd nymph F. virgata, with the mortality rate of more than 70% at 48 h after treatment. The results of laboratory toxicity determination showed that 24 h and 48 h after treatment, the relative virulence of the seven agents ranked from highest to lowest as follows: Thiamethoxam, fenpropathrin, sulfoxaflor, acetamiprid, diazinon, flonicamid·bifenthrin, profenofos·lufenuron. The results of field efficacy test showed that thiamethoxam, fenpropathrin, sulfoxaflor and acetamiprid exhibited the superior field control effect, and the corrected control effect was more than 60% during 1-7 days after treatment, while that of diazinon, flonicamid·bifenthrin, profenofos. lufenuron was less than 60% on 7 days after treatment. Thiamethoxam had the highest field control effect on mealybug bistripe, achieving a corrected control effect of 90.13% after 1 day of application, peaking at 94.53% after 3 days, and maintaining a substantial efficacy of 87.20% after 7 days, which was significantly higher than that of the other insecticides. The results of this study demonstrated that thiamethoxam, fenpropathrin, sulfoxaflor had good laboratory insecticidal activity and field control efficacy against F. virgata. The findings would provide a scientific basis for selecting suitable pesticides for controlling F. virgata, and also offer technical support for the prevention and control strategy of areca palm yellow leaf disease.

In order to screen cocoa breeding materials with excellent fruit traits, pulp and cocoa bean quality, 17 indicators including fruit quality, fruit shell quality, fruit length, fruit width, fresh quality of seeds, pulp content, soluble sugar, total acid, pH, sugar-acid ratio, pulp sensory evaluation (aroma, sour-sweet taste, acceptance), cocoa butter, theobromine, caffeine, and polyphenols were measured for 11 cocoa germplasm. Principal component analysis and cluster analysis were used to comprehensively evaluate the 17 indicators of different cocoa germplasm fruits. The results indicated that the coefficients of variation (CV) for the 17 indicators ranged from 4.16% to 52.91%, with an average of 16.73%. Notably, caffeine exhibited the highest CV among all indicators. The CVs for pulp content, total acid, sugar-acid ratio, and caffeine were all above 20%, suggesting significant variations in fruit traits and quality among the 11 cocoa germplasms. This rich genetic diversity indicates a vast potential for the selection and improvement of cocoa cultivars with desirable characteristics. In the sensory evaluation of cocoa pulp, variety Xiangke 16 scored the highest, followed by TAS420 and TAS1413. Furthermore, the acceptability among testers was primarily influenced by the balance of sweetness and sourness in the pulp. Correlation analysis revealed that there were mainly positive correlations between fruit traits and pulp quality, while there were primarily negative correlations between cocoa bean quality traits and both fruit traits and pulp quality. In the principal component analysis, a total of five principal components with eigenvalues greater than 1 were extracted, accounting for a cumulative contribution rate of 89.521%. Based on the principal component scores of each indicator, a comprehensive ranking was conducted, with TAS420, Xiangke 16, and TAS414 scoring the highest. The three cocoa germplasm exhibited superior performance in fruit traits, pulp quality, and cocoa bean quality. Principal components 1 and 2 played crucial roles in the comprehensive evaluation. Among them, indicators such as pH, sugar-acid ratio, sensory evaluation, fruit quality, fruit shell quality, and fruit width contributed significantly to the evaluation of cocoa fruits. Based on the cluster analysis, the 11 cocoa germplasms were subdivided into four groups. Group I consisted of TAS1413, which exhibited superior fruit traits and pulp quality but had the poorest cocoa bean quality. Groups II and III comprised the top four germplasm in the comprehensive ranking, demonstrating excellent overall indicators and serving as important materials for breeding superior varieties. The remaining six germplasm belonged to Group IV, which had relatively average fruit traits and quality. This study would provide a foundation for the breeding of superior cocoa varieties, contributing to the diversification and development of the cocoa industry.

The Nujiang Dry-hot Valley region in Yunnan is an ideal area for the cultivation of Arabica coffee (Coffea arabica L.). However, the continuous occurrence of coffee leaf diseases has a significant impact on the health, yield and quality of coffee trees, causing considerable losses to local agricultural production. To effectively manage the diseases, this study focused on the isolation and identification of the pathogens associated with coffee leaf diseases in the Nujiang Dry-hot Valley region. Typical diseased leaf samples were collected from various coffee plantations, and through pathogen isolation, purification, verification using Koch’s postulates, morphological observation and ITS gene sequence analysis. Seven pathogenic strains, Lu 11-2, Lu 9-1, Xin 5-2, Xin 7-5, Xin 8-2, Xin 15-2 and Lu 23-1, were identified. Lu 11-2, Lu 9-1, Xin 5-2 and Xin 7-5 were identified as Alternaria sp., Xin 15-2 and Lu 23-1 were identified as Colletotrichum sp., and Xin 8-2 was identified as Pestalotiopsis sp. The primary pathogens causing coffee leaf diseases in this region could be categorized into three types, Alternaria sp., Pestalotiopsis sp. and Colletotrichum sp.. Specifically, Alternaria sp. and Pestalotiopsis sp. were the primary pathogens responsible for coffee leaf spot disease, while Colletotrichum sp. was the causative agent of coffee anthracnose disease. The findings of this study would not only provide a scientific basis for a deeper understanding of the types of coffee leaf diseases in the Nujiang Dry-hot Valley region of Yunnan but also offer theoretical support for effective disease management in the area. This research plays a significant guiding role for local coffee cultivation and serves as a reference for disease control in coffee-growing regions elsewhere.

In order to study the effect of chalcone isomerase on the synthesis of flavonoids during the development of rubber leaves, this study used the CHI functional domain chalcone (PF02431) to identify the HbCHI gene family members of the Ccalcone isomerase, and to analyze the physicochemical properties, conserved domain, conserved motif and phylogenetic tree of the protein sequences. qRT-PCR was used to analyze the expression pattern of HbCHI during the development of rubber leaves. The effect of HbCHI2 on plant flavonoid synthesis was analyzed using Agrobacterium-mediated transient expression technique in Nicotiana benjamina. Nine HbCHI gene family members (HbCHI1-HbCHI9) were identified from the genomic database of H. brasiliensis. The proteins encoded by HbCHI1-HbCHI9 contained 177-474 amino acids with isoelectric points ranging from 5.1 to 9.52. The proteins were mainly hydrophilic proteins. Only HbCHI1 contained 6 conserved motif1-motif6 motifs, and phylogenetic analysis showed that HBCHI1-HBCHI4 was type I CHI. HbCHI6-HbCHI9 showed fatty acid binding sites, which were type III CHI. HbCHI5 was type IV CHI. The relative expression level of HbCHI gene family in rubber trees showed a trend of first decreasing and then increasing from small bronzer to mature stage. The relative expression level was the lowest in light green stage, and the change trend of total flavonoids content was consistent with the relative expression level of CHI gene. Correlation analysis showed that HbCHI2 had the highest significant correlation with flavoniods content. The Pearson coefficient was 0.97. Overexpression of HbCHI2 in N. benjamina promoted the biosynthesis of flavonoids and increased the total flavonoids content in leaves, which was 2.13 times that of control. These results indicate that HbCHI2 gene regulates flavonoid biosynthesis in rubber leaves.