In order to explore the breeding direction of new rice varieties in the Huanghuai rice region, this study focused on nationally approved rice varieties in the Huanghuai rice region in the past 10 years (2013-2022), and analyzed the basic situation, characters, and change trends of rice varieties. The results showed that the number of nationally approved rice varieties in the Huanghuai rice region first increased and then decreased. The average annual increment in yield was 49.5 kg/hm². The four yield factors including effective panicles, grain numbers per panicle, seed setting rate, and 1000-grain weight all assumed an increase with each year, increasing by 3600/hm², 1.03 grains, 0.12%, and 0.11g respectively. Grain numbers per panicle and 1000-grain weight contributed more to the yield growth, while the effective panicles were negatively correlated with yield. The head rice rate and amylose content were relatively ideal, while chalkiness degree was poor. Gel consistency showed a decreasing trend. The neck blast gradually became heavier. The breeding of rice varieties in the Huanghuai rice region should focus on pursuing large panicles on the basis of appropriate number of panicles, and ensure seed setting rate and 1000-grain weight by enhancing photosynthetic characteristic through ideal plant type; chalkiness was the main indicator limiting the quality of rice in the Huanghuai rice region, and attention should be paid to the selection of gel consistency; the resistance of rice blast resistant genes was weakening, and it was necessary to continue exploring and introducing resistance sources or resistance genes.

The aim was to discuss the effects of irrigation, drought and nitrogen on canopy light distribution of multi-spike and large-spike wheat, providing parameters for crop growth model. Taking nitrogen as main treatment, irrigation and drought as two sub-treatments, multi-spike ‘Jimai 22’ and large-spike ‘Lumai 21’ were used as test materials, the data of canopy light distribution at booting stage, flowering stage and filling stage were measured by using American CI-110 canopy analyzer. The results showed that MLA of different types of winter wheat decreased first and then increased with the growth stage, and the TCRP value of ‘Lumai 21’ was higher than that of ‘Jimai 22’ at booting stage. With the increase of zenith angle, the TCRP value of irrigation or drought decreased in both cultivars, TCDP decreased first and then increased in two cultivars under different nitrogen, irrigation or drought conditions, and K value increased with the increase of zenith angle. Nitrogen application and irrigation promoted the canopy light distribution of winter wheat at booting stage. The leaf area index (LAI) and leaf inclination angle (MLA) were increased at booting stage by irrigation and increasing nitrogen fertilizer, TCRP value of spikelet-type varieties increased at 7.5° and 22.5° zenith angle, TCDP value of spikelet-type varieties increased at high n. When N was medium or low, TCDP decreased first and then increased, and K value increased with the increase of zenith angle. The nitrogen and water supply of winter wheat with multi-panicle type should be earlier than those with large panicle type, which is beneficial to rational canopy light distribution at booting stage. This study has guiding significance for higher yield of different types of winter wheat varieties under fertilizer and water management.

The study aims to explore the germination status of different sugar beet materials under salt stress, and screen sugar beet materials with strong salt tolerance. In this study, three beet materials (‘TD801’, ‘TD802’, ‘TD805’) were treated with simulated salt stress with concentrations of 0, 50, 75, 100, 150 and 200 mmol/L NaCl solutions. The activity indexes and salt tolerance coefficient of different sugar beet materials under different concentrations of NaCl solutions were determined, and the salt tolerance performance of the beet materials was comprehensively evaluated by principal component analysis and membership function method. The results showed that some of the vitality indexes of different sugar beet materials under different sodium chloride concentration stress showed different trends. According to the principal component analysis of the salt tolerance coefficient of sugar beet seed germination index, the characteristic value of the first principal component was 5.921, and the contribution rate was 74.012%. Based on the membership function method and the comprehensive evaluation of D value analysis, it was found that ‘TD801’ had strong salt tolerance among the three types of sugar beet materials, followed by ‘TD802’ and ‘TD805’, which could provide a theoretical reference for the selection of suitable sugar beet materials in saline-alkali land.

To explore the physiological and ecological response mechanism of different sweet sorghum varieties and screen better sweet sorghum restorer lines under drought stress, PEG-6000 aqueous solution with concentration gradients of 50 g/L, 100 g/L, 150 g/L and 200 g/L was set in this study, and water treatment was used as a control. The germination rate, germination potential, germ length, radicle length, radicle dry weight, germ dry weight and dry matter transport rate of different treatments were measured. The result showed that germination rate, germination potential, germ length, radicle length and dry matter transport rate all showed a downward trend with the increase of PEG concentration. Under different treatments, the germination potential of variety 2 and variety 7 showed the best performance, and did not decrease significantly under the concentration less than 200 g/L, and decreased by 11.5% and 17.8% compared with the control under the concentration of 200 g/L. The germination rate of cultivar 7 showed the best performance, and decreased the least (5.6%) under the treatment of 200 g/L PEG concentration. The radicle length of cultivar 6 showed the best performance and increased by 7.1% under concentration of 150 g/L. The germ length of cultivar 3 and cultivar 4 showed the best performance, and decreased the least compared with the control under concentration of 100 g/L and 150 g/L. The dry matter transport rate of cultivar 2 showed the best performance, and showed the least decrease under all treatments compared with the control. Different sweet sorghum varieties showed different response mechanisms on drought stress. According to the comprehensive evaluation of drought resistance by membership function, the order of drought resistance of 8 sweet sorghum lines was variety 3> variety 7> variety 4> variety 6> variety 2> ‘variety 5’> ‘variety 8’> ‘variety 1’.

Potato is an important food crop and is very sensitive to high temperature. In order to study the effects of high temperature stress on the physiological characteristics and yield of potato leaves, ‘Qingshu 9’was used as the experimental material, and the leaf area, chlorophyll content, photosynthetic fluorescence characteristics and yield of potato were systematically studied using randomized block design. The results showed that the leaf area index and leaf SPAD value decreased significantly under high temperature stress. The leaf area indexes of T₁ treatment were decreased by 11%-34% compared with T₂ treatment, and they were decreased by 34%-68% compared with T₃ treatment. The SPAD value of T₂ treatment was decreased by 2.43% compared with T₃ treatment. Secondly, the photosynthetic fluorescence and yield also decreased, and the recovery was relatively slow, which inhibited the production of Pn and the absorption and transformation of light energy. The reactive oxygen species increased, and the leaves were dehydrated and wilted to cause death, which would affect the whole growth process of potato, resulting in the final reduction of yield. Therefore, high temperature will lead to the change of functional leaves, which will reduce the photosynthetic performance of potato, gradually shorten the active period, disorder the physiological metabolic activity, and significantly reduce the yield.

In order to explore the overwintering plug seedlings of leaf-vegetable sweet potato in North China, 4 stem sizes (D1, D2, D3, D4 for 4, 6, 8, 10 cm) and 5 plug sizes (32, 50, 72, 105, 128 holes) were set to match 14 treatments, to study the effects of different combinations on seedling survival rate, growth (stem diameter, plant height, etc.) and fresh weight, etc. The results indicated that under the same plug, with the increase of stem segment, the survival rate of seedlings, the number of leaves, stem diameter of the base region and plant height of seedlings showed an increasing trend, and then the fresh weight of the aboveground part and the whole plant also increased, and the highest value was under the treatment of D4. Under the same stem segment, as the number of holes in the plug increased, the number of leaves, stem diameter of the base region, plant height, fresh weight above the ground and fresh weight of the whole plant decreased, due to the effect of the plug size on the underground part, with the treatment of 32 holes being the highest. Under different stem segments and plug sizes, the growth of D4-32 treatment was the best. In mid-March, for the fresh weight of the aboveground part, the treatment of D2-72 achieved the same effect as the treatment of D4-32(no significant difference between the two treatments), with the number of leaves, stem diameter of the base region, plant height and other indexs of seedlings meeting the transplanting conditions; for the fresh weight of the whole plant, the treatment of D2-105 treatment (10.21 g) achieved the same effect as the treatment of D4-32, which could save 228.1% of the seedling area. According to its weight, in mid-January, the fresh weight of the aboveground part and the whole plant under the treatment of D3-72 was close to the level of the above two treatments, which could save 125.0% of the seedling area. Considering the growth and economic benefits of seedlings, D2-105 is recommended when transplanted in mid-March, that is, the combination of stem segment with 2 axillary buds and 105-hole plug. If there is condition for transplanting in mid-January, D3-72 is recommended, that is, the combination of stem segment with 3 axillary buds and 72-hole plug.

The effects of different altitudes and different harvest periods on the biological yield index and quality component index of Pseudostellaria heterophylla were studied to provide reference for the suitable harvest period. The P. heterophylla was planted in the middle and high altitude areas of Taiyang Village, Dongyuan Township, Zherong, respectively. The biological yield indexes such as the number of root tubers per plant, the fresh weight of root tubers per plant, the maximum fresh weight of root tubers per plant, the diameter of the thickest fresh root tubers per plant, the length of the longest fresh root tubers per plant, the average fresh yield of the plot, the average dry yield of the plot, and the quality indexes such as water content, ash content, extract content, polysaccharide content, total saponin content were measured and compared. The results showed that the water content, extract content and ash content of P. heterophylla in the middle and high altitude cultivation areas met the requirements of the 2020 edition of Pharmacopoeia of the People's Republic of China. The high altitude environment was beneficial to improve the biological yield index and quality index of P. heterophylla, but it was not conducive to the accumulation of polysaccharide content. The cumulative peak of underground root biomass yield index and quality component index in middle altitude area was about July 15, and the cumulative peak of underground root biomass yield index and quality component index in high altitude area was about July 26. However, the cumulative change trend of biomass yield index and quality index content in the two places was similar, showing a “single peak curve” type change. The suitable harvest period of P. heterophylla in the middle altitude cultivation area is in mid-July, and the suitable harvest period of P. heterophylla in the high altitude cultivation area is in late July.

In order to study the residual status of agricultural film used in greenhouses and analyze the effects of different types of agricultural films on soil nutrients and chilli yield, this study set the no mulching treatment as the control (P₁), and six treatments covered with 0.01 mm black PE film (P₂), 0.006 mm black PBAT film (P₃), 0.008 mm black PBAT film (P₄), 0.01 mm black PBAT65%+PPC35% film (P₅), and 0.01 mm white PBAT65%+PPC35% film (P₆), to analyze chilli yield, residual amount of agricultural film and soil nutrients. The results showed that using different types of agricultural film could increase chilli yield, improve soil moisture conditions, and the residual amount of agricultural film and its impact on soil nutrients differed from different types of agricultural film. Compared to the control, the content of available potassium increased in all film covering treatments; the content of soil available phosphorus increased in P₂, P₃, and P₄ treatments, while soil available phosphorus content decreased in P₅ and P₆ treatments. The use of different types of agricultural mulching treatments can increase the yield and fresh weight of chilli, and the effect of 0.006 mm black PBAT film was most significant; The 0.01 mm white PBAT65%+PPC35% film had the highest residual amount, while the 0.01 mm black PE film had the highest degradation amount and degradation rate. The results of principal component analysis indicated that the degradation rate of agricultural film, ammonium nitrogen, and available phosphorus were the main factors affecting the yield of chilli. Overall, the use of 0.006 mm black PBAT film in greenhouses is more conducive to increasing chilli yield and soil nutrient content, making it an optional material for vegetable production in greenhouses.

Polyethylene (PE), as one of the most used plastics in the world, has widely existed in the natural environment because of its wear-resistant, high molecular weight and indestructible properties. PE would break down into microplastics (MPs) and accumulate in large quantities, and currently MPs has become an important pollutant that affects the ecosystem. Currently, many studies have been demonstrated that PE could be partially degraded, but further research is needed in screening of microorganisms or enzymes that could completely degrade PE and construct a complete biodegradation pathway for PE. Therefore, this paper summarizes the classification, recycle methods and characterization methods of PE, microorganisms and enzymes that degrade PE, biodegradation pathways and influencing factors, and proposes future research directions of PE biodegradation. These findings provide theoretical basis for the degradation mechanism of PE.

This study aims to explore the impact of the “VIP+n” comprehensive cadmium control technology system on cadmium-polluted paddy fields in the central and southern parts of Hunan Province. The experiments were conducted in Yaotian town of Leiyang City for two consecutive years, including plot comparative experiments and large-scale demonstration experiments. In the plot comparative experiments, 10 treatments were employed to compare the effects of measures such as low-cadmium-accumulating rice varieties, continuous flooding irrigation, application of quicklime, microbial agents, and foliar inhibitors on cadmium-polluted paddy fields. Based on the results of the plot experiments, three cadmium-reducing technologies with good efficacy and economic feasibility were selected for large-scale demonstration experiments. The results showed that the “VIP+n” cadmium control technology system effectively reduced the cadmium content in rice grains in cadmium-contaminated paddy fields. Compared to the control group, the cadmium reduction rate for early rice using this technology system ranged from 59.66% to 79.45%, while for late rice, it ranged from 46.85% to 48.23%. Among the various cadmium reduction measures, the application of quicklime significantly reduced the cadmium content in rice grains, and the use of low-cadmium varieties alone had a significantly higher cadmium reduction effect than using quicklime alone. In contrast, continuous flooding irrigation, application of microbial agents, and foliar inhibitors did not show significant cadmium reduction effects.

This study aimed to investigate the impact of different forms of potassium fertilizers on enhancing the soil quality and productivity of tobacco fields. Through a combination of indoor incubation experiments and field trials, the bioavailability of soil potassium after the application of various potassium fertilizers was assessed. The indoor incubation experiments analyzed the changes in the content of non-exchangeable potassium (NEK), exchangeable potassium (EK), and water-soluble potassium (WSK) in the soil after treatment with three types of potassium fertilizers. The results showed that these three forms of potassium constituted 17.7% to 83.9%, 11.1% to 56.0%, and 2.3% to 36.3% respectively. Applying Silicon-based potassium fertilizer (Si-K) raised the content of EK and NEK in the southwest, Huang-huai and northeast by 26.3% and 18.1%, 30.8% and 24.5%, and 36.3% and 42.7%, respectively. Grey correlation analysis revealed that the total K, texture, and mineral composition of soil were the primary variables influencing the amount of K extracted by NaBPh₄. Field experiment indicated that, compared with 0K, the partial substitution of K₂SO₄ by Si-K could increase tobacco leaf yield (8.7%), and K content (66.6%) while lowering residual K in the soil. In conclusion, Si-K could aid soil K maintenance. Partial substitution of K₂SO₄ by Si-K could increase tobacco quality and quantity. Partial substitution with Si-K merits further study.

Nitrogen is one of the three major nutrients required for plant growth, and nitrate nitrogen and ammonium nitrogen are the two main nitrogen forms absorbed by plants. Nitrate nitrogen and ammonium nitrogen play different roles in plant growth. Plants mainly absorb nitrate nitrogen through roots to meet the needs of nitrogen in the growth process, and convert it into synthetic raw materials for bioactive substances such as amino acids and proteins. At the same time, nitrate nitrogen participates in the synthesis of chlorophyll and promotes photosynthesis. Ammonium nitrogen can also be absorbed by plant roots and used for the synthesis of proteins and amino acids in plants, and the absorption rate of ammonium nitrogen is fast, which can meet the rapid demand of plants for nitrogen. Due to the different growth characteristics of plants, the utilization efficiency of nitrate nitrogen and ammonium nitrogen by plants is different. The genotype and environmental factors of plants will affect their ability to utilize different nitrogen forms, forming that some plants prefer nitrate nitrogen, while others prefer ammonium nitrogen. In this paper, the related research progress was reviewed from three aspects: the influencing factors of soil nitrogen form and transformation, the mechanism of nitrogen absorption by plants and the prospect of efficient nitrogen cycle and transformation, so as to provide technical and theoretical reference for scientific research such as nitrogen fertilizer regulation and soil ecological restoration in crop production.

A soil incubation experiment was conducted to study the effects of cement, Mn-P modified biochar and Mn-P modified rice husk ash on soil pH and the available concentration of Cd, Pb and trace elements (Zn, Fe and Mn) in lead smelting site soils under four application rates of 0%, 1%, 2% and 4%. The results showed that with the increase of cement application rate, the pH of the lead smelting site soils significantly increased, and the availability of Cd and Pb decreased gradually. The soil pH of a smelting site in Jiyuan and a smelting site in Zhuzhou treated with cement increased by 0.89-1.84 and 0.89-1.76 units, respectively. The DTPA-Cd concentration treated with cement decreased by 34.3%-53.1% (P<0.05) and 59.6%-73.2% (P<0.05), and DTPA-Pb concentration decreased by 21.6%-44.7% (P<0.05) and 38.4%-44.3% (P<0.05), respectively. With the increase of application rates of Mn-P modified biochar and Mn-P modified rice husk ash, the soil pH, and Cd and Pb availability in lead smelting sites gradually decreased. The treatment of 4%Mn-P modified biochar reduced the soil pH of two lead smelting sites by 0.51 (Jiyuan) and 0.40 (Zhuzhou) units, respectively. The DTPA-Cd concentration significantly decreased by 18.0% (Jiyuan) and 39.8% (Zhuzhou), and DTPA-Pb concentration significantly decreased by 37.8% (Jiyuan) and 63.1% (Zhuzhou). The soil pH value of the two lead smelting sites treated with 4% Mn-P modified rice husk ash decreased by 0.70 (Jiyuan) and 0.23 (Zhuzhou) units, respectively. The DTPA-Cd concentration significantly decreased by 14.9% (Jiyuan) and 30.2% (Zhuzhou), and the DTPA-Pb concentration significantly decreased by 37.3% (Jiyuan) and 54.1% (Zhuzhou). The DTPA-Zn concentration in the soil of two lead smelting sites treated with 4% cement significantly decreased by 36.5% (Jiyuan) and 59.4% (Zhuzhou), respectively, and the DTPA-Fe concentration significantly increased by 122.7% (Jiyuan) and 142.9% (Zhuzhou), and the DTPA-Mn concentration significantly decreased by 13.8% (Jiyuan) and 69.1% (Zhuzhou), respectively. The treatment of 4% Mn-P modified biochar significantly increased the soil DTPA-Zn concentration by 48.7% (Jiyuan), and the DTPA-Mn concentration significantly increased by 409.7% (Jiyuan) and 538.6% (Zhuzhou), and the DTPA-Fe concentration significantly decreased by 33.4% (Jiyuan) and 30.7% (Zhuzhou), respectively. The treatment of 4% Mn-P modified rice husk ash significantly increased the soil DTPA-Zn concentration by 63.0% (Jiyuan), and the DTPA-Mn concentration significantly increased by 290.3% (Jiyuan) and 73.5% (Zhuzhou), and the DTPA-Fe concentration significantly decreased by 9.5% (Jiyuan) and 12.0% (Zhuzhou), respectively. The order of reducing Cd availability of three passivation materials in two lead smelting sites was cement>Mn-P modified biochar>Mn-P modified rice husk ash, and the order of reducing Pb availability was cement>Mn-P modified biochar>Mn-P modified rice husk ash (Jiyuan) and Mn-P modified biochar>Mn-P modified rice husk ash>cement (Zhuzhou). It was necessary to select suitable passivation materials based on the Cd and Pb pollution characteristics of lead smelting sites to achieve synchronous immobilization of soil Cd and Pb.

To provide theoretical basis for the cultivation and identification of virus-free seedlings of P. praeruptorum Dunn. cv. Xinzhou, its tobacco mosaic virus was identified, its protein was expressed and its sequence was analyzed. The protein gene of tobacco mosaic virus of P. praeruptorum Dunn. cv. Xinzhou was identified by lncRNA sequencing and RT-PCR, and its protein of tobacco mosaic virus was expressed by E. coli recombinant technology, and its gene sequence was analyzed by bioinformatics method. The protein genes of tobacco mosaic virus of P. praeruptorum Dunn. cv. Xinzhou included replicase (ORF1), movement protein (ORF2) and coat protein (ORF3). The replicating enzyme, movement protein and coat protein of tobacco mosaic virus could be detected by RT-PCR, and could be recombined and expressed in E. coli, indicating that the sequencing result of lncRNA of tobacco mosaic virus was accurate. The total length of the cDNA of the replicase, movement protein and coat protein genes of the tobacco mosaic virus was 3351 bp, 807 bp and 480 bp, respectively. The replicase, movement protein and coat protein of tobacco mosaic virus from P. praeruptorum Dunn. cv. Xinzhou were closely related to tobacco mosaic virus, with the homology of 99.64%, 98.88% and 98.74% respectively. Peucedanum praeruptom tobacco mosaic virus (PpTMV) has occurred in seven districts or counties in Xinzhou, Guangxin, Yushan, Guangfeng, Wuyuan, Dexing and Yiyang, the main producing areas of P. praeruptorum Dunn. cv. Xinzhou in Shangrao, Jiangxi Province. This article is the first report of PpTMV detected in P. praeruptorum Dunn. cv. Xinzhou.

In order to clarify the influence of different temperatures on the spawning mechanism of M. dilatata, and lay a theoretical foundation for the large-scale breeding and application of M. dilatata, three temperature treatments were set, including constant temperature at 25℃, variable temperature at 25/30℃ and constant temperature at 30℃. The pre-spawning period, egg production amount, hatchability rate and adult weight of M. dilatata in each treatment were recorded during the experimental process. The results showed that there was no significant difference in egg production between 25℃ constant temperature, 25/30℃ variable temperature, and 30℃ constant temperature, and there was no significant difference in pre-spawning and male and female body weight. On days 10th and 25th after the start of spawning, the hatchability of 25℃ constant temperature was significantly higher than that of 30℃ constant temperature and 25/30℃ variable temperature (P<0.05), and there was no significant difference in the hatchability of the eggs during the 30-day observation cycle, there was no significant difference in hatchability of the next generation eggs between treatment groups. This study showed that 25/30℃ variable temperature and 30℃ constant temperature reduced the hatchability of eggs of M. dilatata to some extent and had no effect on pre-spawning, egg production and adult weight. This study could provide the data basis for the spawning mechanism and application of M. dilatata.

To test the efficacy of plant-based pesticides against tobacco aphids hosted by cigar, evaluate their safety to tobacco aphid cocoons, explore the feasibility of joint control, and scientifically guide the prevention and control of tobacco aphids in cigar, pyrethrins and rotenone were selected to conduct efficacy tests on tobacco aphids in greenhouse potted cultivation. The safety of tobacco aphid cocoons was evaluated through indoor toxicity testing of tobacco aphids and tobacco aphid cocoons. Both commonly used plant-based pesticides have control effects on tobacco aphids hosted by cigars. Over time, the efficacy gradually increases, reaching its peak at 7 days after treatment. The corrected control effect of pyrethroids is 74.75%, and that of rotenone is 80.96%. The safety of the two commonly used plant-based pesticides to the tobacco aphid cocoon bee are all at risk, with a safety coefficient of 48 hours being less than that of 24 hours; within 24 hours, it has good selectivity, and within 48 hours it is non-selective. Both plant-based pesticides have good control effects on tobacco aphids. Over time, the control effect on tobacco aphids increases, but it will reduce the safety and selectivity of tobacco aphid cocoons. The feasibility of joint prevention and control is not ideal.

The research on the starvation tolerance of Athetis dissimilis larvae is helpful to understand the living habits of this insect and to better control the pest. In this study, the survival rate, growth and development of A. dissimilis larvae were measured by starvation and refeeding after starvation. The results showed that all larvae from 2-day-old to 12-day-old died after starvation treatment, and the hunger tolerance became stronger with the increase of day-old. The average survival time of 12-day-old larvae was 11.90 days after starvation treatment. After starvation treatment, 64.4% of 14-day-old larvae could pupate. After the refeeding treatment, life period of 4 and 8-day-old larvae was significantly prolonged and the pupa weight was significantly decreased with the extension of starvation time. After the 12-day-old larvae were starved for a short time, the larval development time increased significantly, but the pupa weight did not decrease significantly. The results indicated that the older the larva, the stronger the ability to resist hunger, and the larva could cause repeated damage after repeated feeding. The results of this study provide a theoretical reference for the scientific control of this insect.

To understand the effect of different humidity conditions on the enzymatic browning reaction of cigar tobacco leaves and its chemical composition, providing a theoretical basis for the modulation of cigar tobacco leaves, under the conditions of three different curing humidity, the effects on the moisture content of the cigar tobacco leaf, pigment, polyphenol oxidase (PPO), polyphenols and the chemical composition after curing were studied. The results showed that, (1) moisture and plastid pigments of cigar tobacco showed a decreasing trend under different air humidity conditions. (2) Polyphenol oxidase activity increased first and then decreased. (3) Polyphenols increased slowly and then decreased. The humidity range of cigar tobacco leaves was controlled under medium humidity conditions. The moisture content of the tobacco leaves was suitable for the life activities of the tobacco leaves. The degradation rate of plastid pigment was the fastest. The enzyme activity was low, the accumulation of polyphenols was more, and the chemical composition was coordinated. This shows that regulating the humidity of the cigar tobacco leaves can effectively improve the beneficial effect of the enzymatic browning reaction on the cigar tobacco leaves and improve the inherent quality of the tobacco leaves.

Mining, chemical industry, metallurgy, agricultural cultivation discharge heavy metal pollutants into rivers, lakes and seas, resulting in heavy metal residue pollution of fish. Heavy metal residues in fish have the characteristics of enrichment, biological toxicity, and persistence, and are difficult to degrade through their own actions. It not only threatens the development of fisheries and the health of aquatic ecology, but also the safety of human diet. The article categorizes the accumulation characteristics and summarizes the accumulation patterns of metal residues in fish. Furthermore, the sources, occurrence, and migration and transformation patterns of metal residues in fish are analyzed. Finally, developmental and constructive suggestions for the current monitoring work are put forward, in order to provide reference for further research on heavy metal residues in fish.

The aim is to obtain the fermentation strains with remarkable ability to produce enzyme and antibacterial property, and provide reference for the conversion of new feed resources and the search for antibiotic substitutes. Using strain H14 as the starting point, its enzymatic property and antibacterial ability were analyzed. The feed addition and fermentation time of fermented rapeseed meal were optimized by single factor experiments. A strain of Bacillus cereus H14 that produces cellulase, protease, amylase, and xylanase was screened and identified. The optimal reaction conditions for cellulase production were 60℃ and pH 9, and the activity of cellulase, protease, amylase and xylanase was 11.51 U/mL, 73.68 U/mL, 5.96 U/mL and 14.02 U/mL respectively. The maximum inhibitory diameters against Escherichia coli and Staphylococcus aureus were 18.200±0.200 mm and 17.567±0.493 mm, respectively. The optimal conditions for fermenting rapeseed meal to produce cellulase were adding 25% rapeseed, incubating for 48 h, enzyme activity reached 12.608 U/mL, and the optimal antibacterial effects on Escherichia coli and Staphylococcus aureus were adding 25% rapeseed meal and incubating for 48 h, the antibacterial diameter (mm) was 24.933±0.204; and adding 25% rapeseed meal and incubating for 72 h, the antibacterial diameter (mm) was 27.400±0.529, respectively. The fermentation products contain sucrose, xylose, and glucose. This experiment screened out a good fermentation strain, which could provide some reference for the development of fermented feed.

Currently, Varroa destructor is acknowledged as a harmful parasite of honeybee colonies in the bee industry, leading to significant economic losses and ecological issues worldwide. In recent years, effective control of Varroa destructor in honeybee colonies has been elusive. While traditional physical, chemical, and biological control methods have been crucial in preventing and managing Varroa destructor, each approach has its own advantages and drawbacks, and persistent issues and limitations remain. This study reviews the latest research progress on the biological characteristics, pathogenicity, diagnosis, and control methods of Varroa destructor, offering valuable insights for future research and the prevention of Varroa destructor in honeybee colonies.