To explore the mechanism of tobacco male sterility and search for the key causes, this paper concludes the present research status of male sterility in tobacco based on phenotype, cytology, physiology & biochemistry, molecular mechanism and so on. Firstly, we summarized that the distinguish characteristics of tobacco sterile lines and their maintainer lines in tapetum and flower organs. Secondly, we analyzed that the effects of free proline, active oxygen, enzyme and endogenous hormones on the tobacco fertility. Finally, we described in detail that the research and analysis of the association of nuclear genes, mitochondrial genes and chloroplast genes with tobacco fertility. Furthermore, it is presented that the follow-up studies combined with the high-throughput data effectively will be benefit for the systematical research of male sterility on tobacco.

Phosphorus in soil directly determines plant growth and crop yields, but phosphorus existing forms in soil are very complex, and those phosphorus forms that can be absorbed and utilized by plants account for only a small part of total phosphorus. Therefore, it is important to study the existing forms and classification methods of phosphorus in soil to improve the phosphorus use efficiency of crops, explore ways to enhance phosphorus availability, and reduce phosphorus loss. In this paper, the existing forms of phosphorus in soil, influencing factors of soil phosphorus availability and phosphorus classification methods were reviewed. The results show that the forms of phosphorus in soil consist of two major categories: inorganic phosphorus and organophosphorus, phosphorus absorbed by plants is mainly water soluble inorganic phosphorus, and other forms of phosphorus are difficult to be absorbed by plants, causing low utilization efficiency of phosphorus in soil. There are many factors that lead to low phosphorus use efficiency, mainly ions like calcium, iron and aluminum, and organic matter, pH, temperature, moisture etc. To study and improve the mechanism of the influencing factors could effectively enhance phosphorus utilization efficiency. At the same time, with the continuous improvement of phosphorus classification methods by domestic and foreign scholars, the effective forms of phosphorus have been studied more in-depth and accurately. Bowman-Cole organophosphorus classification method and Hedley’s phosphorus classification method are the two most widely used methods at present.

Low temperature is an abiotic stress that could affect plant growth and vegetation distribution. Once the environmental temperature is continuously lower than the optimal temperature for plant growth, the plant would suffer low temperature stress, including chilling injury and freezing injury. Chilling injury refers to the damage on plant caused by low temperature of zero degree or above. The cells do not freeze at this temperature, but the cold will have physiological obstacles for thermophilic plants, causing injury or death. Freezing damage refers to the phenomenon that plants are damaged or die because of the low temperature below the freezing point. Previous studies mainly focused on the regulation mechanism of low temperature stress on plants, including the process in plants from the perception of low temperature signal to the expression of functional genes, and to the resistance to low temperature stress. This article reviews the research on cold stress on plants in recent years, analyzes the research status from the aspects of signal perception, signal transduction, functional gene expression, cold-induced physiological and cellular regulatory mechanism, and discusses the prospect of the research on plant cold resistance. It will provide a theoretical basis for cultivating new cold-resistant plant germplasms.

Agricultural and forestry waste is a valuable biomass resource. If the resource cannot be used efficiently, it will cause serious environmental pollution and even great harm to human health. Therefore, the resource utilization of agricultural and forestry wastes is the important content of controlling agricultural non-point source pollution, saving biomass resources, energy conservation and emission reduction, protecting the ecological environment, achieving the goal of peaking carbon emissions and carbon neutralization, and social and economic sustainable development. In order to promote the resource utilization of agricultural and forestry wastes, this paper summarized the progress achieved in this field at home and abroad in recent years.

In order to further study the role of endotransglucosylase/hydrolases (XTHs) in the regulation of plant growth and development, this review summarized the structures and mechanism of XTH, the functions of XTH in plant leaves, roots, stems, flowers and fruits, and the XTH expression in response to plant hormone and environmental factors. Meanwhile, the authors recognized XTH as a key enzyme in cell wall remodeling, which could loosen and strengthen cell wall, and participated in cell wall degradation and synthesis. At last, several potential problems in XTH gene research field were put forward, and the future research directions were suggested.

In order to remove the inherent complex resistance structure of lignocellulose and achieve efficient utilization of lignocellulose, new lignocellulosic pretreatment technologies have been improved continuously. As green solvents, Deep Eutectic Solvents (DESs) have the advantages of low cost, simple preparation, thermal stability, and designability. They have great application potential in promoting the pretreatment of lignocellulose and enzymatic hydrolysis, and have received widespread attention. Based on the analysis and summary of the research status and achievements at home and abroad, the research progress of synthesis and properties of DESs, pretreatment mechanism, enzymatic hydrolysis, and bioethanol conversion were discussed. It was pointed out that different hydrogen bond donors and different pre-treatment conditions had a significant impact on the lignin removal rate and glucose yield. It was believed that pretreatment of lignocellulose with DESs could greatly improve the saccharification rate. Prospects for DESs pretreatment mechanism, recycling, and process parameter optimization were proposed.

Waterlogging stress is an important factor that affects the distribution, growth and development of plants. The research on plant waterlogging tolerance is critical to improving plant tolerance in order to cope with the increasingly severe extreme weather and the large-scale production management. In order to carry out researches on plant waterlogging tolerance and explore the regulation mechanism of different plants in response to waterlogging stress, we summarized the effects of waterlogging stress on plant growth, the regulation mechanism of plant in response to waterlogging stress, and analyzed the effects of waterlogging stress on plant phenotypic traits, biomass, photosynthesis, reactive oxygen species accumulation, sugar content as well as biological membrane in detail. In addition, the regulation mechanism of ethylene signal molecule, reactive oxygen species scavenging mechanism, osmotic regulation, morphological regulation, molecular and metabolic regulation of plant in response to waterlogging stress were also analyzed. Finally, it is proposed that further in-depth study should be focus on the development of exogenous regulatory substances to improve plant waterlogging tolerance.

Under the background of cultivated land resource shortage and an increasing contradiction between human and land in east China, it is urgent to increase cultivated land to ensure a ‘balance of occupation and compensation’. Coastal saline-alkali land, as a potential land reserve resource, has strategic and practical significance by its rational development and utilization to alleviate the pressure of land resource shortage, improve agricultural water resource utilization efficiency and ecosystem stability. This paper introduced the current situation and main characteristics of coastal saline-alkali land resources, and summarized the recent research progress and existing problems of coastal saline-alkali land improvement and utilization from the physical, chemical, hydraulic engineering and biological aspects, and put forward the research prospect of coastal saline-alkali land in the future from biophysical process, obstacle reduction, soil fertility improvement and nutrient expansion, development and application of new materials, soil carbon sequestration, and comprehensive management and remediation, aiming to provide new ideas, new technologies and theoretical support for coastal saline-alkali soil improvement under the background of ecological civilization in the new era.

To elaborate the mechanism of anthocyanin biosynthesis in plants and understand the various factors affecting anthocyanin synthesis as well as their interaction, we summarize the internal and external regulatory factors and concluded the environmental factors such as light, temperature, carbohydrate and hormone. Around the anthocyanin biosynthesis pathway, the structural genes in the pathway and its upstream transcription factors are described and analyzed. This study concludes that in plants, all kinds of external and internal factors regulate structural genes through the main transcription factors, affect the biosynthesis and accumulation of anthocyanins in plants, and maintain the dynamic balance of anthocyanins in plants. This regulation includes both positive and negative regulation. In summary, metabolic pathway of anthocyanins is gradually improved, at the same time, novel structural genes and transcription factors will be evaluated and used in genetic engineering improving the characteristics of ornamental plants.

Drought is one of the most important abiotic stresses affecting the growth and yield of crops. The risk of crops suffering from drought stress is increasing under climate change. In order to cope with drought, crops show a series of resistance mechanisms, including the changes of morphological characteristics, and physiological and biochemical characteristics (antioxidant enzyme, osmotic regulation substances, and endogenous hormone), which play an important role in improving the resistance of crops under drought conditions. This paper summarized the response mechanism of crops to drought stress and introduced the measures to improve the drought resistance ability of crops, including: (1) selecting drought-resistance cultivars to promote the absorption of deep soil water; (2) soil mulching, which could reduce soil evaporation and increase soil water content; (3) water-saving irrigation techniques, such as micro-sprinkler irrigation and drip irrigation, which could precisely control the irrigation application and increase irrigation frequency; in addition, partial root-zone irrigation could reduce luxurious transpiration and soil evaporation by regulating stomatal closure; (4) anti-transpirants, which could inhibit excessive transpiration of water by forming ultrathin transparent protective film on the surface of crop branches and leaves; (5) plant growth regulators, which could enhance crop drought resistance by regulating plant physiological metabolism; (6) nano-fertilizers, which could promote plant growth and development by changing physiological and biochemical reactions of crops and enhance drought resistance of crops; (7) biochar, which is beneficial to soil aeration and water retention, and could improve soil physical properties and soil water retention capacity. In order to provide a theoretical basis and technical reference for coping with drought stress, this paper systematically discussed the action mechanism, application prospect and existing problems of the above 7 measures.

The paper aims to explore the reuse of tea residues. We reviewed the researches on the reuse of tea residues in recent years at home and abroad, found that the reuse of tea residues tended to be saturated in industrial and agricultural fields, but there was little research in the field of animal husbandry, and the research direction could be adjusted to animal husbandry in the future. We briefly summarized the sources and compositions of tea residues, and then elaborated the applications of tea residues in 3 fields of industry, agriculture and animal husbandry, focusing on the researches of tea residues as animal feed in animal husbandry; finally, based on the existing researches on tea residues, we put forward the prospects of applying Wanglaoji tea residues as ruminant animal feed to provide a reference for the development and utilization of Wanglaoji tea residues in the future.

The substitution of chemical fertilizers by organic fertilizers is an effective strategy to reduce the amount and increase the efficiency of chemical fertilizer. It also significantly stimulates crop yield and soil fertility. However, it is worth noting that the substitution of chemical fertilizers by organic fertilizers could contribute to greenhouse gas emissions and pollution loading in soil environment. This paper reviewed the effects of organic fertilizer application on crop quality, soil amelioration, greenhouse gas emissions and agricultural non-point source pollution. Besides, we summarized current research of organic fertilizer application and put forward proposals for further studying the organic fertilizer application. Firstly, constantly optimizing the fermentation process to improve the quality of organic fertilizer is of overarching importance. Secondly, it is suggested to strengthen the quality trait evaluation in assessing the application effect of organic fertilizer, and take full advantage of long-term positioning observation and modern monitoring means to improve the soil fertility monitoring level and accomplish the comprehensive environmental effect evaluation. These suggestions aim at providing guidance for rational and efficient application of organic fertilizers, and for sustainable utilization of soil and water resources.

In order to screen out maize inbred lines with excellent combining ability from 80 declassified inbred lines of the United States, analyze their utilization potential and provide the basis for rational utilization, we used PH6WC and PH4CV as test varieties to explore the combining ability and comparative advantages of the 80 maize inbred lines by NCII genetic design. The results showed that the genetic basis of the 80 American inbred lines was rich and there were real differences. The materials could be divided into 33 female parent groups and 47 male parent groups. Among the 80 test materials, LH206, PHN66, NL001, 2FACC, 6M502A, 29MIBZ2, 1538, LH128, LH181, Lp215D, PHR30, LH214 and LH213 had excellent GCA effect value for yield. The TCA effect values of PH6WC×6M502A, PHW51×PH4CV, NL001×PH4CV and LH128×PH4CV in the cross combination were excellent, and their comparative advantages were relatively strong, so further test could be carried out. The NL001, 2FACC, 29MIBZ2 and 1538 were suitable for mechanized harvesting, and the GCA showed excellent performance. Also, 6M502A, NL001 and LH128 had relatively high general combining ability, and they could be used as key inbred lines.

Cadmium pollution not only affects plant growth, but also threats to human health, which has been the study hotspot of domestic and foreign. This paper reviewed the effect on Cadmium to plant growth, the mechanism of uptake, transport and resistance of plant to Cadmium. And some new ideas for future research directions are put forward.

Iron (Fe) is the earliest discovered and most abundant essential microelement in plants, which is involved in many physiological processes and metabolic pathways, Fe deficiency will seriously affect the growth, development, yield and quality of plants. Fe in plant-derived food is the main source for animal and human to obtain Fe, and insufficient Fe uptake can damage their health. In order to fully understand the metabolic physiology of Fe in plants, and promote the cultivation of iron-rich plants and the development of iron-rich food, in this review, the contents, forms and proportions of Fe in soil and plants were summarized, the distribution and function of Fe in plants were concluded, the different efficient absorption strategies of plants in small amount of soluble Fe environment were compared, and the regulation mechanisms of Fe transport in cells and long-distance in plants were analyzed. Based on the above, some research prospects were discussed in view of the previous research, it is suggested that more attention should be paid to the differences and molecular mechanisms of Fe metabolic pathways among different plant species, the Nramp family genes regulating approach of the docytotic mechanism of Fe deficiency in plants, the oxidation precipitation and reduction release mechanisms of ferritin (Fer) in the plastids, and the biofortification measures for increasing Fe content and bioavailability in plants.

The study of seasonal frozen soil change in Shanxi Province has important application value for revealing the response of seasonal frozen soil thawing to climate change and the direct impact of land degradation caused by frozen soil change on agricultural production, irrigation and water conservancy infrastructure and road construction in the Loess Plateau under the background of climate warming. Based on the frozen soil data from meteorological observation records at 108 stations in Shanxi Province from 1981 to 2018, this paper analyzed the spatiotemporal variation characteristics of the ground freezing date, thawing date, the number of frozen days and annual maximum depth of frozen soil, and the interannual and interdecadal variation characteristics of the annual maximum frozen soil depth, and the responses of the above factors to climate warming. Results showed that soil freezing in northern Shanxi began in September, and the frozen soil subsided in May at the latest. The depth and area of frozen soil reached the maximum at the end of winter and the beginning of spring. The date of ground freezing was postponed and the date of ground thawing was earlier, and the number of frozen days was reduced accordingly to various degrees in most parts of the province from 1981 to 2018. The annual maximum depth of frozen soil gradually decreased from north to south. The annual maximum depth of frozen soil decreased in the middle and southern parts of the province, and increased in the northern part, which might be related to the warming and wetting of winter climate in north Shanxi. Under climate warming, winter precipitation and 0 cm ground temperature had complex response relationship with the annual maximum depth of frozen soil. The annual maximum depth of frozen soil was negatively correlated with 0 cm ground temperature under the background of excessive winter precipitation. The decreasing trend of the maximum frozen soil depth was a direct response to the increase of the annual average temperature, and the response of the maximum frozen soil depth to the annual average temperature was more significant than that to the annual precipitation.

Crop modelling can simulate crop growth in a variety of the simulation scenarios based on the present research experiments, predict some unknown risks, optimize the management measures of agricultural resources and provide scientific guidance for management of agricultural production. APSIM model is just typical representative of crop model. In order to study structure characteristics of APSIM model and its application in China, in the paper we expounded development history, the operational framework and module structure of APSIM model firstly, then we summarized the application of assessment under climate change in China and farmland management of APSIM model and its applications in climate zone of China. At last, some problems existing in the application of APSIM model in China are pointed out and we provided some suggestions for the application of APSIM model such as APSIM model combined with RS and GIS technology.

Leguminosae, as important food and cash crops, have been widely valued. Rhizobia are gram-negative bacilli which are ubiquitous in soil, and can form symbiotic nitrogen fixation system with legume plants. Rhizobium can not only increase the yield of plants, but also have no effect on the surrounding ecological environment. The symbiotic system of Rhizobium and leguminous plants has the highest biological nitrogen fixation efficiency, accounting for more than 65% of the total biological nitrogen fixation. The in-depth study of the symbiotic nitrogen fixation system is beneficial to the sustainable development of China’s agriculture. In recent years, more and more scholars have been involved in the classification, identification and application of Rhizobium. In this paper, the classification, morphological level, physiological and biochemical level, cell components, nucleic acid molecular level identification and application of Rhizobium are reviewed, which could provide references for the practical application of Rhizobium.

The causes, influencing factors and prevention and control technologies of foodstuff browning at home and abroad are summarized. According to different conditions, browning can be divided into enzymatic browning and non-enzymatic browning, while non-enzymatic browning can be further divided into Maillard reaction, caramelization, ascorbic acid oxidative decomposition and polyphenols oxidative dimerization. There are many factors affecting browning. The factors affecting enzymatic browning include substrate type and concentration, enzyme activity, oxygen, temperature and pH, etc. The factors affecting non-enzymatic browning vary with different reactions, among which temperature and pH are the most important factors. Based on the occurrence mechanism and influencing factors of browning, the prevention and control technologies of browning include physical and chemical prevention and control technologies and the combination of both. This paper points out current problems in fruit and vegetable storage and browning prevention and control technology development, such as high energy consumption, high cost and low safety. Moreover, it further suggests that the browning prevention and control technology should be mainly physical one, supplemented by necessary chemical technology treatment, and the focus should be on the excavation of new materials and new inhibitors.

In order to study the genetic basis and genetic relationship of current rice varieties in Heilongjiang Province, 47 pairs of SSR markers published in the agricultural industry standard Protocol for the Identification of Rice Varieties SSR Marker Method (NY/T 1433—2014) were used to analyze the genetic diversity among 231 rice varieties from different accumulated temperature regions in Heilongjiang Province. The results showed that a total of 136 alleles were detected form the 47 pairs of SSR markers, alleles per locus ranged from 2 to 5, the average was 2.92. Genetic diversity ranged from 0.11 to 0.79, with an average of 0.56. The polymorphic information content (PIC) was 0.11-0.76, with an average of 0.49. The value of marker index (MI) ranged from 3.18 to 18.39, with an average of 6.52. Cluster analysis divided the 231 rice varieties into 3 categories and 7 groups, and the clustering results were consistent with the results of principal component analysis. Taken together, the genetic diversity of rice varieties in Heilongjiang Province is not rich enough (the average polymorphic information content index is 0.49), and the genetic relationship among the varieties in the same accumulated temperature area is relatively close. In variety breeding, attention should be paid to the hybridization of northern and southern varieties, in order to broaden the genetic background and cultivate new environment-friendly varieties with high-quality and high-yield.

Copper (Cu) is an essential metal for human body, animals and plants, and participates in various morphological, physiological and biochemical processes. Copper is a cofactor of many enzymes and plays an important role in photosynthesis, respiration and electron transport chain. It is also a structural component of defense genes. In order to provide more systematic theoretical reference for the future study of copper stress on plants, based on the adverse effects of excessive copper on physiological processes such as plant germination, growth, photosynthesis and anti-oxidation summarized in previous studies, this paper reviews the biological functions of copper, the toxicity of excessive copper to plant growth and development, the role of copper transporters and chaperone proteins, and the tolerance mechanism of plants to copper stress. The future research direction is prospected, which provides a basis for formulating effective strategies to maintain copper homeostasis.

To reveal the pathways and mechanisms of the interaction between plants and soil microorganisms, the authors reviews the research progress of the promotion of plant growth and development by rhizosphere beneficial microorganisms and the effects of plant rhizosphere secretions on soil microbes, mainly include the promoting effect of rhizosphere-promoting microorganism PGPM on plant growth and development, the promotion of biocontrol microorganism BCA on plant growth and development, the composition of root exudates, the function of root exudates, and the pathway of root exudates affecting soil microbes, etc. The authors point out that the research on the mechanism of interaction between plants and soil microorganisms is not deep enough. The research on the screening and adaptability of PGPM strains, the ecological adaptability of biocontrol microorganisms and the mechanism of action on target pathogens, the separation of root secretion, the optimization of the identification method and the allelopathic approach all need to be further studied. In the future, the application of modern molecular biology technology in related research should be increased, and the interaction between plant and soil microorganisms should be further revealed by combining molecular biology techniques with traditional culture methods.

Wheat is the main food crop ensuring food production safety and boosting high quality development of agriculture in China, and the improvement of wheat quality becomes more and more urgent. The quality traits of wheat are complex. After years of genetic improvement, important progress has been made in the study of wheat quality traits, but the wheat quality improvement in China is still at a low level. In this paper, the research status of several important quality traits of wheat was briefly summarized, with the focus on the genetic improvement of traits that control the nutritional quality and processing quality of wheat. The paper mainly analyzed the genetic characteristics of wheat protein content, gluten content, starch content and sedimentation value, and reviewed the molecular genetic laws of each quality trait and the main genes related to regulation. With the development of molecular biology and biotech nology, the genetic regulation of wheat quality traits is clear, and molecular design breeding can be used as a key research method in the future.

The SWEET gene family of plant sugar transporters is a class of important sugar transporters discovered in recent years, which plays an important role in plant growth and development, physiological metabolism, and resistance to stress by regulating the transport and distribution of sugar in plants. SWEET gene has different biological functions in different species and plays an important role in plant life activities. In this study, we reported the research status of the protein structure, transport mechanism and biological function of the SWEET gene family in plants, aiming to provide a theoretical basis for further study on other structures and functions of SWEET gene family.

E-commerce poverty alleviation is an innovative poverty alleviation method which can promotes the development of impoverished areas. As the northernmost agricultural province in China, Heilongjiang Province, on the one hand, has a certain degree of rural poverty, on the other hand, the advantages of a good ecological environment and abundant resources of green agricultural products. Therefore, it is very suitable for implementing targeted poverty alleviation through E-commerce. Through a comprehensive and systematic analysis of the current situation of rural E-commerce poverty alleviation in Heilongjiang Province, it is found that there are some problems such as the “relying on others” thinking of farmers, the lack of leading talents in the E-commerce industry, the low degree of standardization of agricultural products and the relative lack of infrastructure. The study puts forward some suggestions such as improving the awareness of poor households in E-commerce poverty alleviation, cultivating leading talents in rural E-commerce, establishing well-known brands of local agricultural products and improving infrastructure for the further development of E-commerce poverty alleviation in Heilongjiang Province.

To prevent and mitigate the possible adverse effects of heavy snowfall on facility agriculture, production and life, and to improve the level of snow forecast, 19 regional snowstorms in Nantong since 1951 were analyzed from impact systems, atmospheric temperature stratification, dynamic and water vapor conditions by using conventional high altitude and surface data and ECWMF 0.75°×0.75° reanalysis data. The diagnostic analysis and forecasting process were illustrated with the regional snowstorm in 2013 as an example. The results showed that: (1) Nantong belonged to the north subtropical monsoon climate, and the process of rain or sleet to snowstorm accounted for the majority; to judge the snowfall, we should pay attention to the precipitation after snowfall, and the surface temperature for estimating the depth of snow cover, therefore, we must consider the comprehensive influence of strong cold air downward and strong warm and humid air flow northward; (2) the synoptic systems of heavy snowfall mainly included two westerly troughs, one in the north and the other in the south, as well as mid-low level shears, southwest jets and low-level cold cushion, the example was a typical regional snowstorm weather situation; (3) there were at least two strong SW jets at 500- 850 hPa altitudes, and the strong convergence rise mainly occurred at 700 hPa and above, which provided dynamic and water vapor condition for the formation of snowstorm; the cold cushion was below 850 hPa, and there was a temperature inversion between 850 and 700 hPa; when the air temperature of 850 hPa was ≤-4℃ and air temperature of 2 m level was ≤3℃, the precipitation changed to snow, and the snow cover increased obviously after the surface temperature approached zero; (4) the average 24 h SLR (snow to liquid ratio) in Nantong was more than 10 in pure snowfall snowstorm, the process of rain or sleet to snowstorm was less than 10, and that in the southeast was less than 5, and the precipitation phase transition and SLR could be generally prejudged by air temperature of 850 hPa, and temperature of 2 m level and surface; (5) it was also a feasible method to find the similar process of weather situation from the historical heavy snowfall, compare stratification, dynamic and water vapor conditions, and then enlarge or reduce the snowfall and snow depth of similar processes to infer precipitation and snow depth.

As an important part of modern agricultural production development, intelligent agricultural machinery equipment plays an crucial role in improving resource allocation and ecological environment, enhancing economic development, promoting rural revitalization and ensuring food security, while accelerating the development of agricultural modernization. Shandong Province, as a large province of agricultural machinery equipment manufacturing and application, still has problems such as unbalanced development of agricultural machinery equipment industry, low level of intelligent equipment, insufficient integration of agricultural machinery and agronomy, and backward construction of basic conditions for mechanization. This study analyzes the status quo of the intelligent agricultural machinery equipment. In view of the problems of the development of intelligent agricultural machinery industry in Shandong Province, we deeply dissect the domestic and foreign cutting-edge technologies and the industrial developing trends. In combination with the urgent needs of the modern agricultural and rural development, we put forward future research and application targets of intelligent agricultural machinery equipment in Shandong Province, and further clarify the innovation and support fields of government, enterprises and scientific research institutes, and the key technology research direction in line with the national strategic needs and the requirements of agricultural modernization.

The paper aims to reveal the influence of management area of mulberry field on the annual income of sericulture farmers in western China. During 2015-2018, we conducted a follow-up survey on the level of rural economic development, the transfer of rural labor force, and the production and operation of sericulture farmers in 13 towns in Fucheng. Through the establishment of econometric model, 554 sample data were analyzed to determine the appropriate scale of mulberry field management in western China. The results showed that: (1) the area of land owned by each household was very small with 0.04 hm² per household; (2) the average mulberry field area of sericulture farmers’ independent management was 2.05 hm² per household; (3) the appropriate scale threshold range of intensive management of regional mulberry field was 1.51-12.08 hm²; (4) the functional relationship between the per capita net income of sericulture farmer and the management scale of mulberry field was y=-2491.8x²+33201x, that was to say, the land management scale was 6.66 hm² when the per capita net income was the largest. In conclusion, sericulture farmers are rational and reasonable in determining their own land management scale at present, and there is still a certain space for land demand in the future under better economic conditions.

Understanding the evolution characteristics of major agronomic characters of main planting wheat varieties can provide a basis for new variety breeding and cultivation innovation. 50 main planting wheat varieties of different years in Shandong Province were used as materials, the evolution characteristics of agronomic characters and economic coefficient, and their correlation were analyzed. The results showed that, the plant height presented an extremely significant decreasing trend with the time. Every cultivar alternation decreased the plant height by 6.29 cm on average. The 1000-seed weight showed an extremely significant increasing trend, every cultivar alternation increased 1000-seed weight by 1.26 g on average. The economic yield and biological yield per stem decreased first and then increased, and they showed an extremely significant positive correlation. The economic coefficient increased significantly, and every cultivar alternation increased the economic coefficient by 24.33% on average. There was no significant change trend in spike length, kernel number per spike, total spikelet number, and the number of fertile spikelet in different years. The trend of economic yield and biological yield per stem was different from the trend of grain yield, indicating that the coordination between population yield and individual yield was an important direction to improve grain yield of wheat.

Lignan is considered one of the most important bio-active components in flaxseed, and has attracted attention in recent years because of the efficacies of anti-cancer, antioxidation, anti-inflammation, diabetes prevention and cardiovascular system protection. In order to make a better understanding of the exploitation and utilization of flaxseed lignan, based on the domestic and foreign literature reviews, this article mainly reviewed the research progress on the extraction technology and biological activity application of flaxseed lignan. The effective extraction of lignan from flaxseed is the basis of bioactivity research. Different extraction processes can not only cause the difference in the extraction rate of lignan, but also affect its biological activity. This article summarizes some commonly used extraction methods for flaxseed lignan, including organic solvent extraction, subcritical water extraction and microbial fermentation. At the same time, the application of bioactivities is summed up and the research progress of lignan in the pharmaceutical field is emphasized. This article proposes prospects for the future research direction of flaxseed lignan, aiming to provide theoretical basis for the in-depth research, development and application of flaxseed lignan in the fields of medical industry and health industry.

As a low-cost and environmentally friendly new type of fertilizer, microbial fertilizers can effectively improve soil, increase fertility, increase crop yield, and reduce crop losses caused by pathogens, playing an important role in the national agricultural green development strategy. In this paper, we summarized the development status of microbial fertilizers in China in recent years, the classification and preservation of strains, and the mechanism of soluble and volatile secondary metabolites of plant growth promoting bacteria from the aspects of classification, product application and mechanism of microbial fertilizers, and analyzed the common problems faced by the development of microbial fertilizer industry. Finally, several suggestions for promoting the development of microbial fertilizers were put forward.

The alien invasion is a far-reaching global issue, which has a major impact on the ecosystem, environment, health, society and economic development of countries. Especially in recent years, with the acceleration of global warming and global trade liberalization, the species and amounts of invasive alien species have shown a rapid growth trend, leading to an increasingly serious threat. Without effective prevention and countermeasures, the alien invasion may lead to “bioterrorism”. This paper takes Spodoptera frugiperda which is a major pest invading China in a large scale in FAO global warnings in January 2019, as an example, analyzes the impact of invading organisms on China’s economy, ecology and society, and illustrates the possible invasion pathways of alien organisms, and dissects the challenges of prevention countermeasures of alien biological invasion in China in the current era, and also proposes a series of comprehensive prevention and control measures according to the invasion characteristics and impacts of invading organisms, including improving the management mechanism of “unified supervision, division of labor and responsibility”, accelerating the legislation of invasive alien species, completing the well-structured and scientific management system, establishing the law and monitoring system, strengthening the basic research of invasive alien species and the establishment of prevention and control networks, and deepening the science popularization and education.

Pesticides play an important role in ensuring agricultural production, increasing grain yield and improving farmers’ living standards. In the process of pesticide control of pests and diseases, the active ingredients are easily degraded or lost due to the unstable physicochemical properties of the pesticides’ active ingredients and the improper application process. The utilization rate of conventional pesticide formulations is only about 20%. At the same time, there are problems such as fast release rate of active ingredients, short duration of pesticide effect and great influence of environmental conditions. Controlled release nano-pesticide formulation is a hot spot in the research of pesticide formulations. Based on the nano-dispersion preparation technology and the slow and controlled release characteristics of pesticide carriers, the serious loss of active ingredients of pesticide can be solved by combining nanotechnology with pesticide characteristics, control target, application environment and application methods, so as to improve the effective utilization rate of pesticide formulations. The active ingredients can be released continuously and stably in a specific time and space according to the requirements of pest control dose, which has met the requirements of pest control economically, safely and effectively. In this study, the research progress of nano-biomaterials in controlled release nano-pesticide formulation was reviewed, and the application prospect of controlled release nano-pesticide formulation was discussed.

The use of pesticides plays an important role in controlling pests in crops, especially for vegetables and fruits. However, the unreasonable use of pesticides has caused excessive pesticide residues, environmental pollution and other problems. China has a vast territory, and the situation of pesticide residues in vegetables and fruits is different in different regions. Therefore, this study analyzed the current situation of pesticide residues in four economic regions of China in recent ten years and explored the residues’ differences in different varieties, purchase sources and seasons of vegetables and fruits. Then, this paper discussed different household processing methods to reduce the pesticide residues in vegetables and fruits. Based on the analyses above, the paper put forward some relevant suggestions on scientific and rational use of pesticides, as well as effective methods for removing pesticide residues in vegetables and fruits.

Microbial exopolysaccharides have important characteristics such as renewability, biodegradability, strong adsorption, anti-inflammatory, antioxidant, and antiviral properties. They have multiple applications in fields of food, pharmaceuticals, cosmetics, and environmental protection. Previous studies mainly focused on the isolation, purification and structure of microbial exopolysaccharides, but there were few reports on the relationship between the structure and function of microbial exopolysaccharides and the role of exopolysaccharides in environmental protection. In order to elucidate the structure-function relationship of microbial exopolysaccharides and expand their applications, this article reviews the impacts of monosaccharide composition, molecular mass, functional groups, glycosidic linkages, and surface morphology on their functions. Furthermore, potential applications of microbial exopolysaccharides in wastewater treatment, soil remediation, and antibiotic elimination for environmental protection are summarized. Due to the low yield and biological activity of microbial exopolysaccharides, their extensive industrial application is limited. It is expected that the yield of microbial exopolysaccharides can be enhanced through genetic engineering techniques, structural modification, and optimization of fermentation conditions and promote their development and application in environmental protection.

Biogas slurry is formed by fermentation of organic substances. Because of its large quantity and inconvenient treatment, it has become one of the sources of environmental pressure. The utilization of biogas slurry in rice production not only alleviates the pressure on environmental protection, but also improves rice yield and soil quality. It is an effective way for the resource utilization of biogas slurry. Biogas slurry is rich in nutrient elements and microbial secretions, which can provide all kinds of vitamins, auxin and amino acids required by rice. Biogas slurry has the functions of promoting rice growth and controlling rice diseases and insect pests. In seed soaking and fertilization, the use of biogas slurry instead of chemical agents can improve the drug effect and reduce the pollution level, but the application rate varies according to the composition of biogas slurry in different places. By summarizing and analyzing the rational utilization of biogas slurry resources, it is found that biogas slurry can not only improve rice yield and economic benefits, but also reduce chemical pollution, improve soil quality and drive the sustainable development of agriculture, which is of great significance to build the balance of agricultural ecological cycle.

In order to comprehensively understand the current status of major diseases in freshwater aquaculture across the country, and identify the existing drawbacks in disease prevention and control, we conducted a survey at the city level in freshwater aquaculture areas. By conducting a comprehensive analysis of disease data from different regions, the types of diseases (a total of 101 species, including 25 viral diseases, 25 bacterial diseases, 6 fungal and algal diseases, 32 parasitic diseases, and 13 other diseases), epidemiological patterns, severity of damage and control measures for aquaculture species across the country were clarified. By further analyzing the existing drawbacks in disease prevention and control, the targeted recommendations for guiding the future development of aquatic disease prevention and control are put forward.

The grain aphid Sitobion miscanthi (Takahashi), considered as S. avenae (Fab.) in China, is one of the most widely distributed aphid species which needs chemical control annually in northern China at wheat grain filling stage. The spatial-temporal population dynamics of the grain aphid is affected by geographical area, meteorological factors, natural enemies, agricultural practices, biodiversity, and resistance characteristics of wheat varieties to aphid at different growth stages in field. In general years, the dynamics of aphid population develop with the wheat growing and temperature rise in field. The aphid number has sporadic occurrence at the jointing stage of wheat seedling and cluster occurrence at booting stage, increases rapidly after head sprouting, and reaches the peak at mid-late stage of grain filling, and decreases sharply at milking stage. The aphid spatial distribution pattern follows random distribution - contagious distribution - aggregated distribution (mosaic distribution) - uniform distribution - aggregated distribution (mosaic distribution)- disappearance. The wheat grain number is affected weakly by aphids before wheat head sprouting because the population of aphids is very small in field. But the 1000-grain weight is significantly affected by the aphid as its population increases rapidly during grain filling stage in field. In this paper, an ecological control strategy is proposed for grain aphid. We suggest that the dynamic control index of this pest should be established according to the resistance/tolerance characteristics of wheat varieties to aphid during different growth stages. The priority should be given to the biological control before wheat head sprouting, and the dynamic control index should be strict; the chemical control should be carried out after head sprouting, and the dynamic control index could be loosened. The utilization of plant protection UAV combined with artificial intelligence is also suggested to automatically discover the occurrence center of aphid and other pests/diseases, and to spray pesticides precisely on the occurrence center in wheat field simultaneously.

The aim was to establish a method for the determination of twelve flavonoid components in Scutellaria baicalensis. The HPLC method was performed on an Agilent ZORBAX SB-C18 column (4.6 mm×150 mm, 5μm) with a detection wavelength of 280 nm and a mobile phase of acetonitrile-0.1% phosphoric acid aqueous solution at a flow rate of 1.0 mL/min and a sample volume of 10 μL. The established extraction and chromatographic conditions were used for the qualitative and quantitative analysis of Scutellaria baicalensis. The linearity of the twelve flavonoids in Scutellaria baicalensis was good in the mass concentration range (r>0.98), and the average spiked recoveries of scutellarin, apigenin-7-O-β-D-glucopyranoside, carthamidin, baicalin, luteolin, chrysin-7-O-glucuronide, wogonoside, apigenin, baicalein, wogonin，chrysin and oroxylin A were 99.7214%, 92.7039%, 103.9755%, 100.5837%, 92.4819%, 93.2465%, 99.6387%, 104.3866%, 95.0767%, 95.3245%, 92.2161%, 95.3995% (RSD<5). A method for the determination of twelve flavonoid components in Scutellaria baicalensis was established, which was easy to operate, reproducible and accurate.

The soil fertility of cultivated land in Gaomi City of Shandong Province was investigated and the spatial distribution of soil fertility was clarified. Eight soil fertility indexes, including soil pH, organic matter, total nitrogen, total phosphorus, total potassium, alkali-hydrolyzed nitrogen, available phosphorus and available potassium, were acquired by gridded sampling and analysis of surface soil. The membership value of each index was determined by the membership function model of fuzzy mathematics, and the weight of each index was determined by principal component analysis. The integrated soil fertility index was calculated using membership value and weight, and then interpolated for mapping. The results showed that the soil in the study area was mainly alkaline, accounting for 37.77% of the total samples, followed by neutral, accounting for 29.52% of the total samples. Organic matter, alkali-hydrolyzed nitrogen and available potassium were mainly insufficient, total nitrogen and total potassium were mainly medium, and total phosphorus and available phosphorus were mainly rich. The membership value of organic matter and total nitrogen were significantly lower than that of other indexes, showing they were the main limiting factors of cultivated land soil fertility. Total nitrogen had the maximum weight value and contributed the most to soil fertility. Alkali-hydrolyzed nitrogen had the minimum weight value and contributed the least to soil fertility. In the study area, the spatial distribution of integrated soil fertility index of cultivated land was mainly medium.