Abstract:The pathway and mechanism of boron(B) acquisition dependent on plant B transporters have been fully revealed，and the physiological response process of plant B deficiency has also been widely studied. In order to deeply explore the adaptability of plants to B deficiency and its potential mechanism，this review systematically summarizes the important research progress from three aspects：the plant B absorption and transport pathway，the physiological response of B stress and the adaptive regulation to stress by B，mainly including B absorption regulation，genetic improvement of B efficient plants，hormones and B stress and the importance of B in other stresses. It is expected to provide theoretical reference for B regulating plant stress adaptation and a way to achieve B efficient genetic improvement.

Abstract:Soil nutrients are always the most direct and main source of nutrients for citrus trees. The level of soil nutrient content directly determines the nutrient accumulation and storage of trees， which is the basis of tree nutrition. The lack of soil nutrients will inevitably lead to the lack of tree nutrients. This article summarizes the relationship between leaf analysis and soil analysis in citrus orchards to diagnose nutrient status， soil and its fertility "deficiency" factors in Chinese citrus orchards. It is defined that the deficiency of calcium， magnesium， boron and zinc in citrus， soil acidification and excess of phosphorus， iron， manganese and copper are the prominent problems of tree nutrition in Chinese citrus orchards. The joint diagnosis of nutrient status in citrus orchards by leaf-soil analysis， as well as the ecological region division of soil based supplementary fertilization and decrement fertilization in Chinese citrus orchards were proposed. It will be of great significance to guide the fertilization and production of citrus with low-carbon and green and high efficiency in China..

Abstract:Slow/controlled release fertilizer can enhance the nutrient use efficiency，which is an important technology to increase nutrient utilization rate，and metal organic frameworks （MOF） provided an alternative option for the development of slow/controlled release fertilizer. MOF，comprised of organic ligands and metal ions/metal clusters via coordinative bonds are highly porous，crystalline materials，and the tunable porosity，chemical composition，size and shape，and easy surface functionalization make this large family more and more popular. There has been a growing interest over the last decades in the design of engineered MOF with controlled sizes for a variety of applications in the fields of chemistry，materials science，medicine，biosensor etc.，but MOF’s application in agricultural science is in initial stage. MOF composition and structure as well as the synthesis approaches were elucidated，and the applications in main fields including in agricultural science were summarized，in particular，the potentials in the application as a new type of slow/controlled release fertilizer was addressed； then challenges in MOF development for slow/controlled release fertilizer were discussed. Multi-nutrient elements could be combined in MOF by directional design in molecular level according to the nutrient demand of crops，which provided new technical support for the development of slow/controlled release fertilizer.

Abstract:In order to explore the comprehensive effects of different forms of molybdenum（Mo） fertilizer on the yield， quality and mineral nutrient content of Chinese cabbage， the varieties of "Shanghaiqing" and "Aijiaohuang" of Chinese cabbage were selected as the experimental materials， the random block experimental design was used to carry out both in field experiment and pot experiment respectively. A total of 6 treatments were set up： no fertilization （CK）， habitual fertilization （NPK）， habitual fertilization+ potassium molybdate （NPK+ KMo）， habitual fertilization+ ammonium molybdate （NPK+ AMo）， habitual fertilization+ molybdenum oxide （NPK+ BMO） and habitual fertilization+ nano molybdenum oxide （NPK+ NMo）. The different effects in yield， quality and mineral nutrient content of Chinese cabbage were compared and analyzed. Compared with NPK treatment， each Mo application treatment could significantly improve the fresh matter of field flowering cabbage and potted Chinese cabbage shoot. Among them， NPK+ AMo treatment had the best effect， which increased 32.3% （field cabbage）， NPK+ NMo and NPK+ AMo treatment could increase 30.8% and 30.2% （potted cabbage）compared with NPK treatment，respectively； the contents of soluble protein， vitamin C and reducing sugar of Chinese cabbage were increased， while the content of nitrate was reduced under Mo application. Compared with NPK treatment， NPK+ AMo and NPK+ NMo treatments significantly reduced the nitrate content of Chinese cabbage by 18.9% and 14.9%，increased the reducing sugar content by 23.8% and 30.2%，respectively， NPK+ NMo treatment could significantly increase the contents of soluble protein and ascorbic acid by 25.8% and 50.2%， respectively； besides， NPK+ AMo and NPK+ NMo treatments significantly reduced the nitrate content in the shoot of potted Chinese cabbage by 27.8% and 29.4%， respectively. In addition， NPK+ NMo treatment significantly increased the contents of soluble protein， ascorbic acid and reducing sugar by 86.5%， 64.0% and 22.2%， respectively； meanwhile， each Mo application treatment could significantly increase the contents of Mo and Mg in Chinese cabbage. NPK+ NMo treatment had the greatest effect， increasing 79.2% and 55.7% respectively； the content of Mg and Mo in the shoot of potted Chinese cabbage in NPK+ NMo treatment increased 74.31% and 96.88% compared with NPK treatment， respectively， while the content of Zn in NPK+ AMo treatment was different from that in NPK treatment， increased by 52.2%. On the basis of habitual fertilization， increasing the application of different forms of Mo fertilizer could improve the yield， nutritional quality and mineral nutrient content of Chinese cabbage， improve the edible value， reduce the nitrate content and improve the edible safety. In general， the effect of increasing the application of NMo was the best， followed by AMo.

Abstract:To explore the yield?increasing effect and physiological mechanism of boron (B)?nitrogen (N) interaction in Brassica napus, the effects of B?N different treatments on rapeseed growth, N uptake and utilization, N metabolism enzyme activity, and seed yield were analyzed by hydroponic culture experiment and field plot experiment. The results showed that B deficiency significantly inhibited the root growth of rapeseed at the seedling stage under different N supply levels. Compared with low N or low B treatment, the balanced supply of B and N significantly increased the N uptake and the expression level of related genes, and improved the activities of nitrate reductase (NR) and glutamine synthetase (GS) in N metabolism. In the field experiment, the application of B and N fertilizer significantly increased the seed yield of rapeseed. However, the effect of B fertilizer application was closely related to soil N availability. Under the normal N supply level(180 kg/hm²), the effect of B fertilizer application was better than that of low N (60 kg/hm²) condition, while high B (18 kg/hm²) combined with high N (240 kg/hm²) limited the further increase of seed yield. Appropriate co?application of B and N significantly improved the N harvest index and promoted the distribution of N to the grains. B and N co?application had significant interaction effects on the growth and development of rapeseed, both in the hydroponic seedling stage and in the field of the whole growth stage. Under the field conditions of this study, the recommended amount of N fertilizer was 180?240 kg/hm², and the combined application with 4.5?9 kg/hm² of borax could maximize the yield increasing potential of rapeseed.

Abstract:To explore the differential effects of boron （B），zinc （Zn），and molybdenum （Mo） on fruit quality and mineral nutrients content of the blueberry，four treatments including conventional fertilizer （CK），B，Zn and Mo fertilizer were conducted in a long-term position experiment of trace elements. The results suggested that the application of B，Zn and Mo could significantly reduce the titratable acid content of blueberry fruits，resulted in the increases of solid acid ratio of fruit by 26.28%，14.73%，and 27.56% compared with the control，respectively. The application of B，Zn and Mo significantly increased the content and accumulation of nitrogen（N），phosphorus（P），and potassium（K） in blueberry fruits，indicated that the B，Zn，and Mo were beneficial to the transfer of N，P，and K elements from plants to fruits. In addition，Zn and B treatments increased Zn accumulation by 28.95% and 21.88%，respectively. Besides，B，Zn，and Mo treatments increased Mo accumulation by 49.37%，58.86%，and 245.57%，respectively. Generally，the comprehensive score of blueberry fruit quality among all treatments was Mo>Zn>B>CK by principal component analysis，indicated that application of B，Zn，and Mo could improve the comprehensive quality of blueberry fruit，especially the Mo application.

Abstract:In order to study the effect of compound fertilizer of different formulations applied on summer maize at one time，a field experiment was conducted to analyze maize yield and component factors，ear traits，nutrient accumulation，nutrient utilization efficiency and economic benefits by setting 6 formulation treatments （30-5-5，33-5-8，28-7-9，27-7-12，28-11-10，29-6-10）. The results show that the average yield of maize under different formulas （28-7-9，27-7-12，28-11-10，29-6-10） reaches 10.5 t/hm²，the two high-nitrogen formulas （33-5-8 and 30-5-5） have lower yields，and the other high phosphorus and/or potassium formulas can increase yields by 6.3%-9.5% and 7.0%-10.2%. Compared with the two high-N formulas，the length of bare tip，the number of missing grains and the seed setting rate of maize increased for the formula with high-P/K. In terms of nutrient utilization indexes，the nutrient harvest index and internal efficiency of the high-N formula were lower than those of other treatments. The total and net returns of the high-P/K formula increased by 4.6%-6.9% and 6.1%-9.4% compared to the 30-5-5 formula，and by 9.3%-11.7% and 19.3%-23.4% compared to the 33-5-8 formula. Under the conditions of this study，the yield，nutrient utilization efficiency and economic benefit of the formula with reducing N，increasing P and K were better than the high-N formula.

Abstract:To investigate the effects of biochar from different feedstocks on acid soil improvement, nitrogen(N) mineralization and nitrification, acid red soil was selected as experiment material, and different biochar prepared from rice straw, rice husk and wood were added to carry out a 50?day indoor culture experiment. Five treatments had been set: CK (control), F ( chemical fertilizer), B₁ (rice straw biochar with chemical fertilizer), B₂ (rice husk biochar with chemical fertilizer), B₃ (wood biochar with chemical fertilizer). The soil basic physic?chemical properties, enzyme activity and the contents of ammonium N and nitrate N were determined to analyze the relationship between soil properties and N transformation. The results showed that rice straw biochar improved soil pH better than wood biochar and rice husk biochar. Compared with CK and F treatment, the soil pH in B₁ treatment increased by 0.10 and 0.64 units, respectively. Besides, the contents of soil organic matter, total N, available phosphorus and available potassium in B₁ treatment were also significantly higher than that of other treatments. Furthermore, the application of fertilizer (F) and biochar (B₁, B₂, B₃) significantly increased the soil N mineralization rate and nitrification rate, and there were significant differences in different biochar treatments. Throughout the 50?day experiment,compared to F treatment,the average N mineralization rates in B₁, B₂ and B₃ treatments decreased by 81.5%, 87.6% and 28.1%, respectively. Meanwhile, treatment B₁ and B₃ could hold soil nitrate N and increase the nitrification rate by 12.0% and 16.0%, respectively, while B₂ treatment reduced the nitrification rate by 18.5%. In addition, the soil carbon and N cycle?related enzymes activity in different biochar treatments were significantly different. Totally, the results indicated that biochar from different feedstocks have different effects on the physic?chemical properties of acid red soil, and the differences of soil properties could affect the N transformation, and rational application of biochar can hold soil N and reduce N loss.

Abstract:In order to determine the appropriate nitrogen （N） fertilizer application rate for maize under straw returning in the black soil of central Northeast China， a site?specific field experiment from 2017 to 2020 was conducted in Gongzhuling County of Jilin Province. The experiment had set 6 different N fertilizer rates （0， 70， 140， 210， 280 and 350 kg/hm²）to analyze the effects of N on maize yield， N fertilizer utilization efficiency and soil N balance under straw returning， and to explore the relationship among N fertilizer rate， maize yield and N surplus rate under straw return. The results showed that the maize yield first increased and then decreased with the increase of N fertilizer application rate under straw returning condition， but the amount of N application to obtain the highest yield was decreasing with the extension of experiment， reduced by 15.8%. The cumulative agronomic efficiency， the recovery efficiency and the partial factor productivity of N application in maize all decreased with increasing rate of N fertilizer application. In additin， soil N residues were significantly increased by 13.0% and 33.6% at high N application rates （280 and 350 kg/hm²） compared with the soil before planting， respectively， while their cumulative apparent N losses reached 578 and 833 kg/hm². The correlation analysis showed that the N fertilizer rate was 188.9 kg/hm²， yield was 11 850 kg/hm²， N recovery efficiency was 40.1% and N loss was 65.7 kg/hm² when the surplus rate was 0. The results indicated that the appropriate N fertilizer rate under straw returning conditions could significantly improve maize yield and N use efficiency， and reduce the apparent N loss. Considering the crop yield， theoretical surplus rate and apparent soil N balance， to apply 179.5-198.4 kg/hm² N fertilizer was the appreciate range under long?term straw incorporation in the experiment region.

Abstract:To study the effects of different optimized practices on the growth of spring maize and soil properties under no mulch (NM) and plastic ?lm mulch (FM) cultivations, and provide the optimized management of phosphorus (P) fertilization that improve P use efficiency, a ?eld experiment with four P fertilization practices was carried out:CK(no P fertilizer), LAPP(localized fertilization of ammonium polyphosphate),BSSP (broadcasted fertilization of calcium superphosphate),LSSP (localized fertilization of calcium superphosphate) .The results showed that in the early growth stage of spring maize, compared with NM cultivation, soil water content and water storage under FM cultivation were increased by 24.7%, and soil temperature was increased by 11%.The aboveground biomass of maize under FM was 1.81 times higher than that under NM after sowing.The accumulation of P in the maize shoot under FM was 1.59 times higher than that under NM.The alkaline phosphatase activity in the LAPP treatment was 28.7%?30.8% lower but 7.4%?20.4% higher than that in the BSSP treatment under FM condition, and 14.8%?45.9% higher than that in the BSSP treatment under NM.Soil available P content in the LAPP treatment was higher than that in other treatments.In addition, at 50?day after sowing, the total root length, root surface area and length of fine root (<0.5 mm) in the LAPP treatment were grow better than that in other treatments.Therefore, film mulching is still the main way to keep water and heat and promote the growth of spring maize in the rainfed areas of Northwest China, and localized application of ammonium polyphosphate is beneficial to the growth of maize and the use efficiency of P fertilizer.

Abstract:In order to evaluate the application effectiveness of integrated soil-crop system management （ISSM） and provide technical support for sustainable high yield and efficiency in regional crop production， based on the long-term （2009－2020） located experiment we discussed the effects of no fertilization（CK），farmer’s practice（FP），high yield management（HY）and ISSM on maize yield，plant phosphorus （P）and potassium （K） uptake，use efficiency and soil P and K nutrient status. The results showed that the grain yield in CK treatment decreased dramatically during the 12-year experimental period，a slightly decreased yield trend was found in FP treatment，while continually increased yields trends were observed in HY and ISSM treatments. Compared with FP treatment，ISSM treatment significantly increased the average yield and plant P and K uptake by 26%，24% and 32%，respectively，and reached 98%，91% and 85% of those in HY treatment. The average use efficiency of P and K fertilizer in ISSM treatment were 18.7，1.2 units higherthan those in FP treatment，and 17.4，24.8 units higher than those in HY treatment，respectively. Compared with FP treatment，the 12-year adopting ISSM significantly increased total and available contents of P and K in 0-20 and 20-40 cm soil layers，and available contents of P and K for all the aggregate size fractions in 0-20 cm soil layer. The positive and significant correlations were observed between all the measured parameters，of which the stronger correlations were found among grain yield，plant P and K uptake and use efficiency，as well as between soil P and K contents and those in the aggregate fractions that > 0.25 mm size. In conclusion，ISSM could achieve long-term high and stable yield for spring maize，increase P and K uptake and utilization in plants，and improve soil P and K nutrient supply capacity，consequently promote the sustainable development in the whole soil-crop system.

Abstract:Screening marker genes play a crucial role in plant genetic transformation，and the development of safe and efficient screening marker genes is of great significance for transgenic crops.The potential of the phosphite dehydrogenase gene ptxD_Q with high catalytic activity as a screening marker gene for rice genetic transformation was comprehensively evaluated by means of tissue culture，nutrient solution screening and foliar spraying.The results showed that when ptxD_Q gene was used as a screening marker，the screening efficiency of resistant callus was about 44.37%-47.28%，significantly higher than that of the resistance genes including hygromycin and glufosinate.The positive transgenic seedlings can be screened by simply culturing transformed seedlings in the culture medium with phosphite as the only phosphorus source.In addition，a method for screening transgenic seedlings by foliar spraying of phosphite was established.Phosphite is less expensive and less polluting than the current antibiotic and herbicide screening systems.As a forward screening system，it has high screening efficiency and has potential value in studying transgenic crops and developing sustainable agriculture.

Abstract:The effects of nitrogen，phosphorus and potassium fertilizer application on the yield of mid-season rice in Yangtze River Basin and its influencing factors were analyzed to provide a scientific basis for nutrient management in this rice planting areas.The data were collected from the rice field experiments conducted by the international plant nutrition institute （IPNI） and the literature searched on CNKI database with keywords “rice” and “rice + yield” in the Yangtze River Basin of China.There were 1 107，745 and 785 groups of NPK data that met the criteria for meta-analysis，respectively.Using no fertilization treatment as the control and the response ratio as the value of yield-increasing effect，the Meta-analysis method was used to study the yield-increasing effect of fertilization on rice in the Yangtze River Basin and its influencing factors including soil basic fertility，planting area，soil organic matter，pH and soil physical and chemical properties.Compared with no application of nitrogen，phosphorus or potassium fertilizers，the application of nitrogen，phosphorus and potassium fertilizers to the mid-season rice in the Yangtze River Basin had a significant effect of increasing yield.The average yield of nitrogen，phosphorus and potassium fertilizers increased by 35.1%，10.9% and 11.9%，respectively，and nitrogen fertilizer had the highest effect of yield increase.Different levels of basic soil fertility had significant effects on the increase of rice yield.The effects of yield-increasing of nitrogen，phosphorus and potassium fertilizers were the highest in the low soil fertility （yield < 5.0 t/hm²），with yield increase rates of 45.9%，15.1% and 17.0%，respectively.The effects of yield-increasing of nitrogen，phosphorus and potassium fertilizers were significantly different in the planting areas of the Yangtze River Basin.The effect of yield-increasing of nitrogen application in Shanghai was the highest，which was 43.9%，and the effects of yield-increasing of phosphorus application and potassium application in Chongqing was the highest，which were 16.4% % and 16.1%.The application of nitrogen fertilizer had the best effect of yield increasing under alkaline soil conditions，and the application of phosphorus and potassium fertilizers was the best under weakly acidic soil conditions（pH 6.0-7.0），with yield increase rates of 39.0%，14.1% and 15.7%，respectively.The effects of yield-increasing of nitrogen and potassium fertilizers were significantly different among different contents of soil organic matter，while the effects of yield-increasing of phosphorus fertilizers were not significant.The effect of yield-increasing of nitrogen application was the best when soil total nitrogen ≤1.0 g/kg，total phosphorus >0.9 g/kg，total potassium <13.0 g/kg，alkali-hydrolyzed nitrogen ≤100 mg/kg，available phosphorus ≤9.0 mg/kg，available potassium ≤70.0 mg.Both phosphorus and potassium fertilizers obtained the best effect of yield-increasing when soil total phosphorus <0.3 g/kg，total potassium >20.0 g/kg，alkali-hydrolyzed nitrogen >150.0 mg/kg，available phosphorus ≤9.0 mg/kg，and available potassium ≤70.0 mg/kg.Low-fertility soils help to increase the effect of yield-increasing of fertilization.However，soil pH and different soil physicochemical properties affect the effect of yield-increasing of fertilization，resulting in differences in the effect of yield-increasing of fertilization among different provinces and cities in the Yangtze River Basin.The effect of yield-increasing of applying nitrogen fertilizer was the highest in soils with low contents of alkaline-hydrolyzed nitrogen，available phosphorus and available potassium respectively，and the effect of yield-increasing of applying phosphorus and potassium fertilizers was higher when the contents of soil alkaline-hydrolyzed nitrogen were high and the contents of available phosphorus and available potassium were low.The application of nitrogen fertilizer in alkaline soil，the application of phosphorus fertilizer and potassium fertilizer in weakly acidic soil had the best effect of increasing yield.Therefore，the nutrient management of rice in each planting area should comprehensively take the soil pH，organic matter and soil physicochemical properties as the basis for fertilizer input into consideration.

Abstract:Based on long-term （1989-） location experiment，the effects of different fertilization measures on morphological changes and accumulation characteristics of phosphorus in dry land of red soil profile were studied.Five treatments including nitrogen，phosphorus and potassium fertilizer （NPK），nitrogen，phosphorus and potassium fertilizer plus peanut straw （NPK+PS），nitrogen，phosphorus and potassium fertilizer plus green manure （NPK+FR） and nitrogen，phosphorus and potassium fertilizer plus pig manure （NPK+PM），and only nitrogen and potassium fertilizer （CK） were set up in the field experiment.The results showed that long-term application of phosphorus fertilizer significantly increased the contents of total phosphorus and available phosphorus in red soil and increased the soil phosphorus activation coefficient （PAC）.The results of the correlation analyses showed that medium active organic phosphorus （MAOP），aluminum phosphate （Al-P） and iron phosphate （Fe-P） in inorganic phosphorus were significantly correlated with available phosphorus （P< 0.05）.In the control treatment，the soil inorganic phosphorus was mainly in closed storage （O-P） （64.54%）.But under different fertilization treatments，exogenous phosphorus was easier to accumulate in aluminum phosphorus （Al-P） and iron phosphorus （Fe-P），especially in NPK+PM treatment （Al-P，CK： 6.27%，NPK+PM： 27.58%； Fe-P，CK： 17.28%，NPK+PM： 37.35%）.The effects of NPK+PS and NPK+FR treatments on phosphorus in soil were mainly concentrated in the plough layer，but NPK+PM treatment still had a great impact on the phosphorus content in the soil layer below 20 cm.There was still a small amount of available phosphorus accumulation in the bottom layer （60-100 cm）.Phosphorus fertilizer and its combined application with organic fertilizer significantly promoted the accumulation and activation of soil phosphorus，especially the decomposed manure with pig manure as raw material.

Abstract:A total of 46 pomelo resources in Guangfeng County and its surrounding areas of Jiangxi Province were identified by SSR molecular marker technique to explore the genetic relationship and origin of Majia pomelo and its main pomelo lines around its origin，and to screen varieties with suitable pollination. The fruit quality-related indexes of Majia pomelo with different cross-pollination combinations were analyzed for two consecutive years. The results showed that Majia pomelo had obvious variation during the long-term seed reproduction and artificial selection. It is most likely derived from the local pomelo in Guangfeng and its surrounding areas through long-term natural and artificial selection. Among the different cross-pollination combinations，native pemolo No. 4 has the best effect on improving the fruit quality of Majia pomelo，which is the most suitable male parent for pollination at present.

Abstract:Puffing is a common physiological disease of mandarin fruits. Based on reviewing literatures at home and abroad， it is clear that the peels of citrus fruits puffing is rough， foamy， thick and perishable. The sponge layer is loose， collapsed and disordered. There is a large gap between the peel and the pulp due to its separation. The content of sugar and acid in the pulp is low. The valve is thick and hard. The juice sac is dehydrated and hardened. The conditions for the occurrence of citrus fruit puffing are described from the aspects including fruit size， maturity， mineral nutrition， climate factors， etc.. The mechanisms of the occurrence of citrus fruit puffing are revealed from the aspects including cytological level， physiological level and molecular level. According to the “asynchronous development” mechanism of citrus fruit puffing， it is urgent to carry out in-depth studies from three levels including source-sink supply， competition suppression and integrated coordination， and strive to solve the problems of citrus fruit puffing through combining “ integrated coordination” with “targeted regulation”.

Abstract:Tulip is the national flower of the Netherlands and other countries，but it is originated from Tianshan Mountain and the Pamir-Alai Mountains between China and Central Asian countries. Turks discovered tulips in the Tianshan valley more than 1 000 years ago and spread and planted them extensively in the Ottoman Empire. The ambassador of the Holy Roman Empire，Busbecq，brought tulips to Vienna in 1559. Clusius，the “patron saint of the tulip”，brought them to Leiden，the Netherlands in 1573. From then on，tulip was spread all over the Netherlands. As a big tulip country，the Netherlands has collected about 2 400 tulip accessions. Hundreds of tulip germplasm resources are also collected and preserved in some countries including Turkey，Britain，Israel，the Czech Republic，Poland and China. The breeding goals of tulips include flower color，flower aroma，flower shape，flowering period，vase life，heat tolerance，disease resistance，low cooling requirement，and bulb proliferation. Through systematic domestication and bud mutation，13 tulip varieties were released in China. Almost all tulip bulbs in China were imported from the Netherland. Quality of domestic tulip bulbs could not bloom well due to improper postharvest treatment and virus-induced degeneration. Through the breeding of new varieties and the proliferation and rejuvenation of tulip bulbs，it is expected to realize the localization of tulip bulbs and varieties in China.

Abstract:The pathogenic fungi causing the rot disease of postharvest chestnut were isolated and purified by tissue separation method to clarify the predominant pathogenic fungi of postharvest chestnut and the control effect of plant essential oil on them.Further morphological and molecular biological identification of the predominant pathogenic fungi was carried out by microscopic observation and double-gene phylogenetic analysis.On this basis， the control effect of a single component of 10 plant essential oils including perillaldehyde， cinnamaldehyde， citral， folic aldehyde， eugenol， linalool， nerol， thymol， carvacrol， and citronellol on the predominant pathogenic fungi in chestnut postharvest was analyzed.The results showed that the predominant rot-causing fungi of postharvest chestnut included Fusarium sp.， Neofusicoccum sp.， Geotrichum sp. and Mucor sp.， among which strains BL-8 and BL-18 were identified as Fusarium asiaticum and Neofusicoccum parvum by double-gene phylogenetic analysis.The single component of 10 plant essential oils had a certain degree of inhibitory effect on the predominant rot-causing fungus strain BL-8 and BL-18 of postharvest chestnut.Among them， carvacrol had the most obvious antifungal activity against the predominant pathogenic fungi of postharvest chestnut， with its EC₉₀ value on the strain BL-8 and BL-18 of 24.431 μL/L and 11.768 μL/L， respectively.It was further found that carvacrol significantly inhibited the growth of the two predominant pathogenic fungi through in vitro pathogen growth inhibition test and natural storage test.Carvacrol fumigation treatment effectively controlled the occurrence of disease in postharvest chestnut caused by the infection of strain BL-8 and BL-18.Therefore， carvacrol as a fumigant has potential application value in controlling fungal diseases of postharvest chestnut.

Abstract:During the process of coevolution between insects and plants，insects successfully localize host plants to determine their feeding habits and niche.Nevertheless，the molecular mechanism of host localizing of insects remains largely unknown.The true fruit flies （Diptera：Tephritidae） are important pests infesting fruits and vegetables all over the world.Research shows that vision and olfaction of tephritid fruit flies play critical roles in host location.Currently，the trapping device which simulates color and odor can trap and kill the tephritid fly effectively，but the effect of trapping and killing is uneven.This paper reviews the progress of the host location behavior through vision and olfaction by fruit flies as well as related molecular basis，and the application effects.Finally，the future perspective is discussed in order to pave the way for developing eco-friendly control measures against fruit fly pests.

Abstract:The regulatory effects of intracerebroventricular （ICV） injection and deprived feed of histidine or valine on the feeding of Chinese perch （Siniperca chuatsi） were studied to explore the direct signal perception of the central nervous system and the indirect signal perception of the peripheral tissues. In the ICV injection test，the control group was injected with phosphate buffered saline （PBS），and the experimental group was injected with histidine or valine or simultaneously with an inhibitor of general control non-derepressible-2 （GCN2） GCN2iB. The changes in food intake of Chinese perch at 1 h and 4 h after injection were detected. In the feed deprivation test，the control group was fed with amino acid complete feed and the experimental group was fed with deprived feed of histidine or valine. The changes in food intake，GCN2 signaling pathway-related factors and appetite genes were detected. The results showed that the injection of either histidine or valine significantly reduced the food intake of Chinese perch compared with the control group （P<0.05）. Simultaneous injection of GCN2iB and histidine restored the food intake of Chinese perch to normal levels. Compared with the control group，the intake of deprived feed of histidine or valine was significantly decreased （P<0.05）. Moreover，the mRNA expression of activating transcriptional factor 4 （atf4），a key activating transcription factor downstream of GCN2 signaling pathway，was significantly down-regulated （P<0.05） in deprived feed of histidine or valine. The mRNA expression level of the appetite factor neuropeptide Y （npy） in the hypothalamus was significantly decreased （P<0.05）. However，there were no significant changes in the mRNA expression levels of agouti-related protein （agrp），pro-opiomelanocortin （pomc），and amphetamine-regulated transcript （cart） genes. In conclusion，both histidine and valine can inhibit the feeding behavior of Chinese perch via ICV administration and feed deprivation. The changes of feeding behavior of Chinese perch are related to the GCN2 signaling pathway. The deprived feed of histidine or valine might result in the anorexia by down-regulating the expression of appetite-stimulating factor npy gene.

Abstract:The three genes including ATP6V0A1，IL20RB，and STX10 were individually knocked out with CRISPR/Cas9 technology （previously established in author’s laboratory） in PK15-CD163-Cas9 cells and IPEC-J2-Cas9 cells to study the effects of three genes on the proliferation of porcine reproductive and respiratory syndrome virus （PRRSV） and porcine epidemic diarrhea virus （PEDV）.The cells with knocked-gene （PK15-CD163-Cas9-ATP6V0A1，PK15-CD163-Cas9-IL20RB and PK15-CD163-Cas9-STX10） were infected with PRRSV.The expression of the ORF7 of PRRSV was analyzed with fluorescence quantitative PCR to detect the proliferation of PRRSV.Meanwhile，the cells with knocked-gene （IPEC-J2-Cas9-ATP6V0A1，IPEC-J2-Cas9-IL20RB and IPEC-J2-Cas9-STX10） were infected with PEDV.The expression of N protein gene of PEDV and the proliferation of PEDV were detected.The results showed that the expression level of ORF7 in the cells with knocked-gene was significantly lower than that of the wildtype cells （PK15-CD163-Cas9-NC，control group）.The expression of N protein gene was significantly reduced in the cells with knocked-gene，compared with the wildtype cells （IPEC-J2-Cas9-NC，control group）.It is indicated that individually knocking out of the three genes significantly inhibits the proliferation of PRRSV and PEDV.ATP6V0A1，IL20RB，and STX10 can play important roles in the proliferation of PRRSV and PEDV.

Abstract:Mebendazole （MBZ） was administered to blunt snout breams （Megalobrama amblycephala） by oral gavage，and water samples were collected at corresponding time points of 0.25，0.5，1，2，3，4，5，6，7 and 8 d after drug administration to study the distribution and excretion of MBZ in the body of blunt snout bream.The liquid chromatography-mass spectrometry （LC-MS/MS） was used to determine the concentrations of MBZ and its metabolites in the water samples after extracted and purified by solid-phase extraction.The fish experimented were killed and its blood，liver，kidney，gill，muscle and other tissues were collected and weighed after the water samples were collected on the 8th day.QuEChERS method was used for extraction and purification，LC-MS/MS was used to detect the concentrations of MBZ and its metabolites in each tissue.The recovery amount in each tissue was calculated.Results showed that the recovery amount of MBZ and its metabolites in the heart，liver，spleen，gill，kidney，intestine etc.was ranged from 3 332.26 to 5 345.52 μg accounting for 13.74%-23.74% of the total dose，with the highest recovery amount in the intestine up to 5.18%-12.85% of the total dose.The recovered amount in other tissues was ranged from 987.22 to 1 907.19 μg accounting for 5.19%-11.40% of the total dose.The recovery amount in water was ranged from 1 561.95 to 4 623.15 μg accounting for 6.44%-21.88% of the total dose.The total recovery amount of MBZ was ranged from 6 295.50 to 10 983.41 μg，with the average recovery ratio of 42.64%.It is indicated that MBZ mainly exists in the form of mebendazole，hydroxybendazole and aminobendazole in the body of blunt snout breams，and no other metabolites were detected after oral gavage.MBZ and its metabolites were mainly distributed in the intestine，liver，other tissues，but the overall recovery ratio was low.It is indicated that mebendazole is poorly absorbed in the body of blunt snout breams，and its metabolic pathway is similar to other animals.Mebendazole is mainly excreted through feces and urine.

Abstract:Taking Procambarus clarkii as the research object，they were randomly divided into 4 groups with 60 tails in each group.They were fed with basic feed coated with florfenicol of 0 （C0），10 （C10），20 （C20） and 30 mg/kg （C30） for 20 d followed by a period of feeding without florfenicol for 15 days to evaluate the elimination pattern.The activities of hepatopancreatic phase Ⅰ drug metabolizing enzymes 7-ethoxycoumarin-O-deethylase （ECOD），7-ethoxyisophenoxazolone-O-deethylase （EROD），aniline-4-hydroxylase （AH），erythromycin-N-demethylase （ERND），aminopyrine-N-demethylase （AND），phase Ⅱ drug metabolizing enzymes glutathione-S-transferase （GST），sulfotransferase （SULT），and uridine diphosphate glucuronosyltransferase （UGT） were measured.Expression levels of cytochrome P450 （CYP450），GST，heat shock protein 70 （HSP70） and metallothionein （MT） mRNA were measured.The results showed that florfenicol significantly reduced phase Ⅰ metabolic enzymes activities but increase phase Ⅱ metabolic enzymes activities （P<0.05）.The results of gene expression showed that florfenicol could up-regulate CYP450 gene expression.Florfenicol of 10 mg/kg up-regulated GST gene expression，but 20 mg/kg and 30 mg/kg florfenicol could inhibit GST gene expression.The inconsistency between gene expression and enzyme activity showed that there was no inevitable relationship between gene transcription and protein synthesis.The results suggest that 10 mg/kg florfenicol maintains the homeostasis of the body by inducing the expression of HSP70，MT and other genes，but high-dose florfenicol is beyond the tolerance of the body and causes damages to the organism.The results of elimination test showed that after 15 days of elimination，except GST enzyme activity，the activities of other drug metabolism enzymes in C10 group returned to normal level，and the expression levels of four drug metabolism genes also returned to normal level.For the sake of safety，when feeding P. clarkii with florfenicol，the recommended dose is 10 mg/kg，which is not only conducive to give full play to the efficacy without being excluded from the body prematurely，but also avoid the body damage and accumulation caused by too high dose of florfenicol.

Abstract:A set of automatic navigation system for rice harvester with dual-motor crawler chassis was designed and tested to solve problems of high rolling rate， poor alignment stability of manual-operated crawler harvester and low field operation accuracy of existing electric crawler machinery for ratoon rice harvesting in the first season. Based on the dual-motor crawler chassis self-designed for the rice harvesting， the relationship between the steering radius of the chassis and the speed of the driving motors on both sides was derived on the basis of the field slip model. An automatic navigation fuzzy controller was designed. The dual-antenna RTK-GNSS is used to obtain the real-time position and heading angle information of the dual-motor crawler chassis. The lateral fuzzy correction controller of the automatic navigation system and the PID controller of the motor speed on both sides control the motor speed in real time to realize the automatic tracking of the working path. The results of road test showed that the average lateral deviation of the automatic navigation system was 0.015 m and 0.021 m when the dual-motor crawler chassis was driven at 0.6 m/s and 1.0 m/s. When the driving speed was 0.6 m/s， the average lateral deviation of the automatic navigation system was 0.050 m. Compared with the navigation system modified with electronically controlled hydraulic steering， this navigation system has precise control volume， fast response speed and small tracking error. It can be used in the row-to-row operation of ratoon rice in the first season to reduce the rolling rate.

Abstract:In the process of automatically processing fish body， fish body orientation and sorting is the basis of pretreating fish body. In this article， a machine vision-based fish body orientation and sorting device was designed to solve the problems of noisy working environment and poor working stability of fish orientation and sorting devices existed. The convolutional neural network Resnet-18 was used to identify the head and tail orientation of the fish， and the image processing method was used to extract the outline of the fish body and perform grid division， then the ventral and dorsal orientation of the fish was judged by comparing the size of the grey scale value. When the tail of the fish was detected to be facing forward， the cylinder pushed it out and rejected it to achieve the head and tail orientation of the fish. When the head of the fish was facing forward， the ventral and dorsal orientation of the fish was judged by the image processing， and then the cylinder pushed it to the edge of the limit plate to bring its belly against the edge， and it fell into the W-shaped chute device under the action of inertia to complete the ventral and dorsal orientation of the fish. The results showed that the success rate of fish orientation was 93.3%. The average recognition time of the algorithm was 0.038 s， and the average orientation time of each fish was 3.725 s. Theoretically， the efficiency of fish orientation can reach 15-16 fish/min， which meets the production requirements of fish orientation. It will provide useful references for the application of fish orientation and machine vision in fishery production.

Abstract:A set of automatic excavation depth control system was designed by comprehensively using sensor technology， hydraulic control technology and PLC control technology to solve the problems of unstable excavation depth of the 4UML-130 vibrating chain cassava harvester， which results in large damage of cassava and high energy consumption. The system designed was made up of profiling mechanism， excavation depth detection mechanism， hydraulic system and control system. The integral separation fuzzy PID algorithm was used to adjust the excavation depth in real time， which effectively achieves the accurate control of excavation depth. The results of simulation and indoor test showed that the overshoot of the control system using integral separation fuzzy PID algorithm was the smallest and the time to reach stability was the shortest in the step response experiment. The error of the control system using integral separation fuzzy PID algorithm in the sinusoidal response experiment was ±0.5 cm， significantly better than that of the other methods.

Abstract:Take the collection of typical road unevenness in the orchard as the research object，establish a road roughness acquisition method based on lidar point cloud processing，built a road roughness acquisition system platform based on 3D lidar，combine point cloud processing technology to complete the extraction of road elevation information.By using AR （autoregressive） model to calculate the road power spectral density based on the proportional analysis method to determine the roughness level，and through the acceleration vibration recorder for system verification，using the system to carry out a typical orchard road unevenness data collection test. The test results show that the roughness of the orchard road surface showed that the cement pavement is mainly concentrated in the B grade，and the B grade accounts for 82.33%. The sand and gravel pavement is mainly concentrated in the C grade，and the C grade accounts for 84.00%. The mud pavement is mainly concentrated in the D，E grade，with D grade accounting for 48.67% and E grade accounting for 31.00%. The results of roughness evaluation indicated that the application of the three-dimensional lidar orchard road roughness acquisition system is reliable and the results of evaluation are accurate. It is suitable for collecting level of road roughness in mountain forests，fruit，and tea gardens.

Abstract:China is a big country of apple producers and exporters，so it is essential to control the quality of exported apples. The soluble solids content （SSC） in apples is an essential factor affecting the quality of apples. Non-destructive inspection of SSC in apples can be realized by near-infrared spectroscopy （NIR）. The model update method combined with the variable screening method was used to perform nondestructive inspection on the SSC in five apple varieties including Red Fuji，Green apple，Golden Delicious，Rose and Lokit to obtain a general robust multi-variety apple model. The results showed that the updated new model achieved high-precision prediction of the SSC in five varieties of apples. At this time，the root mean square error of prediction （RMSEP） of the model was 0.698%，the correlation coefficient of prediction （R_p） was 0.904，the prediction deviation was 0.074%，and the ratio of performance to standard deviate （RPD） reached 2.340. The model was optimized with three waveband selection methods including competitive adaptive reweighted sampling （CARS），successive projections algorithm （SPA） and uninformative variable elimination （UVE） to identify and extract important information bands of the spectrum. The results showed that CARS selected effective wavebands more effectively. The established model significantly improved the analytical performance in new apple varieties，with RMSEP of 0.587%，R_p of 0.928，and prediction bias reduced to -0.052%，with RPD of 2.684. Therefore，the strategy of combining model updating with waveband selection has great application potential in studying and developing the general model of portable near-infrared detector for multi-variety fruits.