China's forestry informatization has entered the stage of smart forestry，and the new generation of information technology plays an important role in the smart forestry. Based on the connotation and development path of smart forestry, this paper refines the system architecture of smart forestry, expounds the research status of key technologies in smart forestry, such as Internet of Things, 3S and BeiDou Navigation, Cloud Computing, Big Data, Mobile Internet, etc., analyzes its main problems, and discusses its development trend and research focus. It is showed that there are some problems in the research of the key technologies of smart forestry in China, such as incomplete infrastructure, high cost, inconsistent technical standards, weak information interconnection, unstable data quality, data mining not deep enough, insufficient technology integration and lack of professional and technical talents. It is suggested that the research focus of the key technologies in China’s smart forestry in the future will be on four aspects: forestry data mining and deep application, forestry cloud remote sensing big data research, forestry block data research, and the deep integration of forestry internet of things, cloud computing, and mobile internet.

Cold resistance and high-yielding are always the core breeding objectives of Yunnan rubber tree planting area in China. The superior clone was selected by artificial hybridization, and was systematically identified by nursery trial, advanced clonal trial and resistance test. The results showed that Yunyan 80-1983 was a fast-growing, high-yielding and early-maturing rubber tree clone which could be tapped 0.5-1 years earlier. In advanced clonal trials, the girth reached 52.7 cm in the seventh year, which was 122.6% of the control RRIM600 (43.0 cm). The dry rubber yield of 1-13 tapping year was 4.3 kg per tree and 1622.7 kg/hm², which was 130.3% and 122.5% of the control RRIM600 (3.3 kg per tree,1324.8 kg/hm²). The cold resistance was basically equivalent to that of RRIM600, lower than that of GT1 and Yunyan 77-4. It is recommended to be planted in the low-altitude and slight cold damage zone in Yunnan. This clone would provide variety support for optimizing the variety structure, increasing the yield and output value in Yunnan and other rubber planting areas.

Gibberellic acid is a typical plant growth regulator, which has the efficacy of increasing yield and fruit preservation for crops. The preparation process of gibberellic acid dry flowable is still lacking systematic exploration, and the fruit preservation test of this preparation on citrus still needs to be verified. The study was aimed to investigate the effect of the wet grinding process of sand mill on the performance of gibberellic acid suspension slurry and to determine the performance of dry flowable prepared by spray drying. The 3% gibberellic acid dry flowable was prepared by the wet sand mill and pressure spray drying equipment, and the final process was screened according to the determination of particle size, viscosity, the retention rate of gibberellic acid content, and other performance indexes of the suspension concentrate through the optimization of the number of wet grinding times, the wet grinding speed, and the size of the diameter of zirconia beads used for wet grinding. The effect of 3% gibberellic acid dry flowable on citrus fruit set, fruit thickness, single fruit weight and soluble solids were tested in field efficacy test. The results showed that the optimal grinding process was 1 mm in diameter of the zirconium beads used for grinding, the grinding speed was 2500 r/min and grould twice. The viscosity of the suspension concentrate before spraying was lower than 200 mPa/s, and the particle size was about 2 µm, and the particle size of the suspension concentrate after spraying was about 3 µm after rehydration, and the retention rate of gibberellic acid was more than 90% after this grinding process, and the low viscosity of the slurry could meet the production requirements. The 3% gibberellic acid dry flowable produced by this process has high suspension rate (>90%), fast wetting speed (10 s), high retention rate of gibberellic acid, and the performance indexes are in accordance with the regulations, and there is no precipitation of suspension slurry during the production process. The results of the field trial showed that the spraying of gibberellic acid dry flowable increased the transverse and longitudinal diameter of the citrus single fruit, the thickness of the peel decreased, the weight of the single fruit increased, the soluble solids increased, and the fruiting rate of the planting area increased. The results provide theoretical support for the industrial production of gibberellic acid dry flowable, and the field trial of gibberellic acid dry flowable prepared in this study in citrus trees can provide reference for the application of gibberellic acid in citrus fruit trees.

Cassava variety Nanzhi 199 (sweet cassava variety, with erect, compact plant shape and generally unbranched at the top) and chili pepper variety Xiangyan 55 (medium maturity small cowpea variety, with good growth and strong adaptability) were used to study the effects of cassava-pepper intercropping pattern on cassava growth, photosynthetic performance, soil enzyme activity, tuber yield and quality. Three different planting densities of chili peppers in chili peppers and cassava intercropping (T₁, T₂ and T₃, with the spacing of 0.4 m, 0.5 m and 0.6 m, respectively) were designed. The results showed that the aboveground growth indexes of cassava under intercropping treatment had different degrees of inhibition in various growth periods of cassava, and the inhibitory effect deepened with the increase of density and time, so the aboveground plant height and stem thickness of T₃ treatment were minimally inhibited; intercropping treatments were able to improve the relative chlorophyll content of cassava seedling leaves, and the intercropping treatments were able to increase the net photosynthetic rate of the whole period of potato production, stomatal conductance, and the cytosolic rate of the tuber expansion period, and intercellular carbon dioxide concentration during tuber expansion, but had no significant effect on the transpiration rate of cassava in all growth periods; intercropping treatments significantly increased the activities of soil urease, acid phosphatase, catalase and sucrase compared with CK, and the activities of the soil enzymes were significantly higher than those of other intercropping treatments by T₃ except for the activity of soil catalase which had no significant difference among the intercropping treatments; intercropping reduced the aboveground biomass and belowground biomass, and the activity of soil enzymes by T₃; intercropping reduced the relative chlorophyll content of cassava leaves at seedling stage. Although intercropping reduced the above-ground biomass and the number of cassava tubers in the below-ground part, it could improve the weight of cassava, and there was no significant difference between intercropping T₁ and T₂ treatments and the yield of CK, while the acreage yield of T₃ was significantly increased by 13.98%; intercropping could effectively improve the quality of tubers, and the contents of various qualities other than soluble sugar and cellulose in T₃ treatment were significantly higher than that of other treatments, among which, the intercropping treatments were able to increase the starch content of cassava tubers to different degrees, respectively, and increased the starch content of cassava tubers to different degrees. Among them, intercropping treatments were able to increase the starch content of cassava tubers to different degrees, which was increased by 13.06%, 8.25% and 19.33% respectively. In summary, cassava intercropping can improve the yield and quality of cassava tubers by increasing the photosynthetic rate and soil enzyme activity of cassava, and then increase the economic benefits of cassava. Finally, the T₃ treatment with 2 rows of cassava and 2 rows of chili peppers (plant spacing 0.6 m) had the optimal cultivation density, which was a suitable cassava-chili pepper intercropping pattern for Hunan production area.

UV-C treatment is an emerging and abiotic stress technology, and is a non-ionizing and non-thermal physi-caltechnology. By using proper dose of UV-C treatment, it can be used to inactivate microbes on the surfaces of food, reduce the decay rate, maintain phytonutrients content and organoleptic quality. According to the research, the application of UV-C treatment is effective in increasing the levels of antioxidants content and the antioxidant capacity of fruits, then it can enhance resistance ability of some fruits, and which makes storage qualities better and extend the shelf life. Combining UV-C treatment with other technologies, such as 1-methylcyclopropene (1-MCP), and coating with all kinds of active compositions, and different packaging so on, it can form a hurdle technique which is a combination by two or more treatment, it can result in synergistic or additive interactions when compared to any single preservation technique in some horticulture. In addition, UV-C treatment is an eco-friendly and a cost effective technology which can be carried out easily without complex equipment on post-harvest and logistics and transportation for their commercialization. This critical review aims to summarize the research conducted on the effects of UV-C treatment on postharvest fruits in the past five years, the review draws the current challenges as well as future perspectives. It is hoped to provide valuable insights for the widespread adoption of UV-C treatment technology.

To clarify the impact of sod-cultural practices on the soil physico-chemical properties in Macadamia orchards, suitable local grass cultivation models were selected. Five common grass species in orchards (Vicia villosa, Trifolium repens, Lolium multiflorum, Vulpia myuros, and Raphanus sativus) were selected in the study with clear tillage as the control to analyze the differences in soil moisture content, temperature, physical properties, nutrients, and fertility among different treatments in orchards. The membership function method was used for comprehensive evaluation. Sod-cultural practices could effectively increase the surface soil moisture content, which was 8.7%~24.0% higher than that of the clear tillage control. Meanwhile, sod-cultural practices could reduce the surface soil temperature of orchards by 7.6% to 16.8%. Compared with tillage, the average soil bulk density in the sod-cultural practice areas decreased by 11.7%. In terms of soil nutrients, sod-cultural practice areas significantly increased the soil organic matter content, with T. repens having the highest soil organic matter content, reaching 32.0 g/kg. Leguminous and cruciferous grass species could significantly increase the soil available nutrient content, while poaceae grass species showed no significant improvement. The soil comprehensive fertility coefficient of the cultivation modes of V. villosa, T. repens, and R. sativus showed the best performance, increased by 51.5%, 49.2%, and 45.4% respectively compared to the clear tillage control. The evaluation of orchard soil fertility could reach a fertile level. The optimal grass cultivation mode obtained using the membership function method was V. villosa. Comprehensive evaluation of the four physical and chemical indicators of soil moisture content, bulk density, temperature, and fertility in each treated orchard by the membership function method revealed the cultivation mode of V. villosa performed the best.

Biogenic volatile organic compounds (BVOCs) serve as a critical link between the biosphere and the atmosphere, playing a vital role in atmospheric chemistry, ozone formation, and the creation of secondary organic aerosols. Volatile emissions from urban forest parks and greenery can have a significant impact on local and regional air quality. In this study, two common Ficus spp. plants with a high planting rate in Haikou were selected, and the BVOCs emissions of F. elastica and F. altissima were measured using the dynamic headspace bagging collection method and identification and analysis by gas chromatograph. The chemical components and emission characteristics of the BVOCs were also investigated. Meanwhile, the experiment continuously monitored environmental factors [temperature (T), photosynthetically active radiation (PAR)] and physiological parameters [stomatal conductance (G_s), intercellular CO₂ concentration (C_i), transpiration rate (T_r)] to further analyze the driving factors of BVOCs emissions in Ficus spp. The results showed 19 and 12 compounds identified for F. elastica and F. altissima. BVOCs emissions from Ficus spp. were dominated by isoprene and terpenoids. Among them, the relative content of isoprene emission from F. elastica increased by 1.82 times in the rainy season compared to the dry season, indicating that F. elastica has a significant potential for isoprene emission. The terpene compounds α-pinene and Caryophyllene made significant contribution. The daily variation of BVOCs in Ficus spp. showed a single-peak emission pattern of “low in the morning and low in the evening, high in the middle of the day”, with the maximum emission of BVOCs occurring at 12：00 or 14：00 noon, when the temperature or photosynthetically active radiation was the highest. BVOCs emissions from Ficus spp. were significantly higher in the rainy season than they were in the dry season. In addition, the BVOCs emissions of Ficus spp. were positively correlated with the temperature and with the photosynthetically active radiation. BVOCs emissions were positively correlated with the physiological parameters, T_r and G_s, and negatively correlated with C_i. This study expands the research field by investigating the emission characteristics of BVOCs from tropical Ficus spp. It provides essential data for enriching the database of BVOCs emission inventories in tropical and subtropical regions and for assessing their environmental impact.

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.

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 level of cyanogenic glucosides content is an important trait for the edible quality of cassava, and Me-CYP79D2 is one of the key enzyme genes regulating cassava cyanogenic glucosides synthesis. This study used the edible variety SC9 as the material, cloned the MeCYP79D2 gene in the cytochrome P450 enzyme family of cassava, analyzed it using bioinformatics software, and detected its expression characteristics in different cassava germplasm tubers using real-time quantitative PCR. The cyanogenic glucosides content was measured using HPLC, and its correlation with the expression level of MeCYP79D2 gene was analyzed. The results showed that the length of the coding region sequence of MeCYP79D2 gene was 1625 bp, encoding 528 amino acids. It belonged to an unstable lipophilic hydrophilic protein with 38 phosphorylation sites. Sequence alignment indicated that the gene was highly conserved, and phylogenetic analysis showed that MeCYP79D2 was closely related to rubber and leprosy trees. There was a significant positive correlation between the expression of MeCYPD2 gene and the content of cyanogen glycosides in cassava roots of germplasms with different levels of cyanogen glycosides. After treatment with methyl jasmonate, the expression of MeCYP79D2 gene in roots was significantly upregulated and the content of cyanogenic glucosides was significantly increased. The results of this study indicates that MeCYP79D2 is involved in cyanogenic glucosides synthesis, providing a theoretical basis for studying the molecular mechanism of cassava cyanogenic glucosides biosynthesis.