2022 年 7 月 18 日,党中央在向"全球重要农业文化遗产大会"所致贺信中强调,加强农业文化遗产保护,进一步挖掘其经济、社会、文化、生态、科技等方面价值,推动构建人类命运共同体.为促进我国农业文化遗产保护理论研究与实践经验分享,研讨农业文化遗产保护工作未来的首要重点与切实途径,促进农业文化遗产保护事业健康发展.
This study aimed to understand the variations in soil organic carbon(SOC)pools,soil temperature and water content and their relationships to mitigate climate change.Therefore,a field experiment was conducted to investigate the seasonal dynamics of SOC,permanganate oxidizable organic carbon(POxC)concentrations,as well as their relationships with soil temperature and water content under different tillage practices during the summer fallow in the drylands of the Loess Plateau in China.The experiment included three tillage practices,i.e.,no tillage,plough tillage and subsoiling tillage during the summer fallow.Results showed that the seasonal changes in the SOC concentrations increased and then decreased at both 0-5 and 5-10 cm depths under plough tillage and subsoiling tillage treatments during the growth period of winter wheat.While the seasonal changes in POxC concentration,soil water content and soil temperature fluctuated.Regression analysis revealed that the soil water content at the 5-10 cm depth had a linear relationship with the SOC concentrations and a quadratic polynomial relationship with the POxC concentrations(P＜0.05),with a better fit under the plough tillage treatment compared to the no tillage and subsoiling tillage treatments.The SOC concentrations showed no significant response to variations in soil temperature at both the 0-5 and 5-10 cm depths.In contrast,the POxC concentrations demonstrated a negative correlation with daily maximum temperature,daily mean temperature and daily minimum temperature.In summary,the findings of our study demonstrated that the seasonal changes in the POxC concentration at 0-10 cm depth were closely related to variations in soil temperature and water content,while seasonal changes in the SOC concentrations were less sensitive to soil temperature under summer fallow tillage treatments in the drylands.This study provides a theoretical basis for the scientific management of SOC pools in dryland wheat fields.
Over past two decades,the application of nuclear techniques has been integrated into many aspects of scientific research and production practice in food and agriculture,and nuclear techniques are unique and irreplaceable in some areas.This review provides a comprehensive overview of the latest developments and major achievements from the nuclear application in major fields of food and agriculture around the world.The application status and innovative development of nuclear techniques in the fields of animal production and health,food safety and control,plant mutation breeding and genetics,water and soil management and agricultural environment,and insect pest control were reviewed emphatically.Considering many severe global challenges faced by the food and agriculture around the world,the authors discussed and showed the prospects and strategic priorities of nuclear application in food and agriculture.
Ubiquitin-specific proteases are a highly conserved gene family that is widely present in eukaryotes and regulate various physiological activities of cellular proteins through deubiquitination.In order to systematically explore the function of the UBP gene family in grape,this study used bioinformatics to identify and analyze the members of the UBP gene family in grape,and further assayed the expression patterns of VvUBP genes by quantitative real-time PCR under different abiotic stresses.The results showed that the VvUBP gene family included 27 members,with coding sequence(CDS)length between 594-4 812 bp and coding amino acid sequence length of 197-1 603 aa.The results of phylogenetic analysis showed that the UBP gene family could be divided into 8 subgroups(GⅠ-GⅧ).The expression levels of VvUBPs in stems were relatively low,and VvUBP27,VvUBP10 and VvUBP23 were expressed at higher levels in tendrils,flowers and leaves,respectively.Gene expression analysis showed that treatments with exogenous methyl jasmonate(MeJA)significantly induced high expression of four genes,including VvUBP5,VvUBP12,VvUBP18 and VvUBP27,and exogenous salicylic acid(SA)treatment significantly induced high expression of VvUBP5 and VvUBP19.The expression of VvUBP15 increased most significantly under 0.6%salt stress,the expression of VvUBP6 decreased significantly under low light stress and VvUBP25 increased the most at high temperature stress for 6 h.In summary,VvUBP gene family members were able to respond to different abiotic stresses,thereby improve the stress tolerance of grapes.The results of this study provide a scientific basis for revealing the mechanism of UBP regulating grape growth,development and stress resistance.
In order to clarify the physicochemical properties and antioxidant activity of Armillaria luteo-virens pigment,the extraction processes of Armillaria luteo-virens pigment using response surface design were optimized,and the stability and antioxidant activity of the pigment were investigated.The results showed that the optimum extraction conditions of Armillaria luteo-virens pigment were:Deionized water as extraction agent,extraction temperature 51℃,extraction time 61 min,the ratio of material to liquid 1:113 g·mL-1,in which the extraction rate was 90.93％.The crude extract of Armillaria luteo-virens pigment was sensitive to light,more stable under dark conditions,and had poor resistance to high temperature and reduction.However,it had a certain degree of acid,alkali,and oxidation resistance.The addition of Zn2+ increased the absorbance of Armillaria luteo-virens pigment,and when the concentration of Al3+ exceeded 0.25％,the absorbance of the pigment decreased.Glucose had little effect on the stability of pigment.When the concentration of sodium benzoate and sucrose exceeded 1％,the absorbance of the pigment increased,which had a significant impact on its stability.The crude extract of pigment had a certain scavenging ability on 2,2-Diphenyl-1-picrylhydrazyl(DPPH),hydroxyl,and 2,2′-azino-bis(3-ethylbenzothiazoline-6-sulfonic acid)(ABTS)radicals,with half maximal inhibitory concentration(IC50)of 2.30,0.01,and 1.00 mg·mL-1,respectively.It had a certain reduction ability on Fe3+.The DPPH IC50 value and ABTS IC50 value were positively correlated with the content of crude polysaccharides and nitrogen,while the hydroxyl radical IC50 value was negatively correlated with the content of crude polysaccharides and nitrogen.This study provided a theoretical basis for the development and utilization of Armillaria luteo-virens pigment.
To explore the difference of stable isotope characteristics of organic tea in Zhejiang Province,72 representative samples from 52 organic tea enterprises in Zhejiang Province were collected.The stable isotope ratios(δ15N,δ13C,δ2H,δ18O)in organic tea were determined by elemental analysis-stable isotope ratio mass spectrometer,the differences in stable isotopes between different tea species was studied,and the stable isotope characteristics of organic tea in Zhejiang Province were analyzed from three geographical scales.The results showed that there was no significant difference in the stable isotope ratio between organic green tea and organic black tea.The δ15N of organic tea in Zhejiang Province ranged from-2.4‰ to 6.7‰,with an average value of 2.0‰,and there was no significant difference at the city scale.At the regional scale,δ15N of organic tea in southern Zhejiang was significantly higher than that in northern Zhejiang.At the national scale,the δ15N of organic tea in Zhejiang Province was significantly higher than that in other producing areas in China.The mean values of δ13C,δ2H and δ18O of organic tea in Zhejiang Province were-27.2‰,-47.9‰ and 26.3‰,respectively,and there were regional differences among some cities.There was no significant difference in the three stable isotope ratios of organic tea between southern and northern Zhejiang.This study provided a scientific basis for the establishment and characterization of stable isotope database of organic tea in Zhejiang Province.
To investigate the effects of growth-promoting bacteria and growth regulators on the salinity variations,rice yield and rice quality of the beach paddy,a rice planting experiment was conducted from June to November of 2020 in the coastal beach area of Nantong,Jiangsu Province.A two-factor split zone design was adopted,and the main zone was treated with seed immersion by growth-promoting bacteria,including clean water(CK),and growth-promoting bacteria of Rudong(RD)and Ningbo(NB).The second zone was treated by growth regulator spray,including clean water(W),"BiHu(0.136%Gibberellic Acid·indol-3-ylacetic Acid·brassinolide)"(T1)and"sodium nitrophenate"(T2).As the results,the salinity of irrigation water during rice cultivation ranged from 0.78 to 1.12 g·kg-1,and the soil salinity variations ranged from 1.11 to 1.87 g·kg-1 during the rice growth season in the CK,RD,and NB plots.Compared with CK,the rice yield increased by 4.65%and 1.83%in the RD and NB plots,respectively;and compared with W,the rice yield increased by 5.50%and 1.05%in the T1 and T2 plots,respectively.Compared with CK-W,the rice yield in RD-T1 increased the most by by 11.66%(P＜0.05),and the values of grain number per panicle and solid grain number were increased by 13.45%and 13.85%,respectively(P＜0.05).Compared with CK,the brown rice rate,amylose,and protein contents of rice in the RD plots were significantly reduced,but no significant effect was found on other quality indexes.According to the results of two-factor analysis,the growth regulator factor had a significant influence on panicle length,grains per panicle,filled grains per panicle and yield,while the growth-promoting bacteria factor had a significant influence on 1 000-grain weight.Moreover,a significant interaction was found between the growth regulators and growth-promoting bacteria specifically on 1 000-grain weight.In conclusion,growth-promoting bacteria combined with growth regulators had significant effect on the yield increase.Growth regulators mainly increased the number of grains per panicle and the number of solid grains,and growth-promoting bacteria mainly improved the 1 000-grain weight.This study provides a technical reference for exploring appropriate agronomic management measures to achieve the purpose of increasing rice yield in tidal flats areas.
Notopterygium incisum is a traditional Chinese herb commonly used in large quantities,and its rhizomes and roots are the major parts used as medicine.Previous studies have found that the content of secondary metabolites,represented by notopterol and isoimperatorin in the rhizomes of N.incisum,is significantly higher than that in the roots,but their biosynthetic pathways and regulatory mechanisms are not yet fully understood.In this study,we used RNA-seq and transcriptomic analysis to compare and analyze the differential expression of genes between rhizomes and roots of cultivated N.incisum.The results showed that:1 222 differentially expressed genes(DEGs)were significantly enriched in pathways including phenylpropanoid biosynthesis,plant-pathogen interaction,MAPK signaling,and plant hormone signal transduction pathways.Transcripts of key enzyme-coding genes such as shikimate O-hydroxycinnamoyltransferase(HCT),cinnamyl-alcohol dehydrogenase(CAD),and peroxiredoxin 6(PRDX6)in phenylpropanoid biosynthesis were significantly up-regulated in rhizomes when compared to those in roots.Several transcription factors of the AP2/ERF,WRKY,C2C2,and NAC families showed significant differential expression between rhizomes and roots,and these factors may be the key transcription factors affecting the biosynthesis of secondary metabolites.The differential expression of genes is consistent with the differences in the content of notopterol and isoimperatorin in the rhizomes and roots of N.incisum.The results of the study can provide a theoretical basis for further research on the accumulation mechanism of active ingredients in the medicinal parts of N.incisum and directed breeding of N.incisum.
In order to explore the physiological and molecular mechanisms of Atractylodes chinensis(DC.)Koidz.in response to drought stress,the plug-seedling technology was used in the analyzation of the physiological characteristics of A.chinensis in response to continuous natural drought for 3-18 d.High throughput transcriptome sequencing was used to analyze the molecular response characteristics of A.chinensis under drought stress.The results showed that,after continuous drought for 6 d,the plant relative water content of A.chinensis was significantly lower than the control,while the content of soluble sugar,proline and malondialdehyde,and the activity of antioxidant enzymes were significantly or extremely significantly higher than the control.After rehydration for 15 d,the CAT activity and plant relative water content of A.chinensis showed no significant difference when compared to the control,however,other indicators were still significantly higher than those of the control.The results of principal component analysis showed that the content of soluble sugar and total protein,the activity of SOD and CAT could well reflect the drought resistance ability of A.chinensis.Under drought stress,the comprehensive evaluation D value of the membership function in A.chinensis was 0.765-0.865.A total of 14 538 differentially expressed genes(DEGs)were obtained through transcriptomic analysis.The most annotated unigenes in GO functional annotations are related to cellular component,and the most annotated unigenes in KEGG classification was glucose metabolism.There are 71 unigenes classified to terpenoids and polyketides metabolic pathway,12 of which encode 7 key enzymes in sesquiterpenoid and triterpenoid biosynthesis pathway.Based on comprehensive analysis,drought stress can affect the expression of related functional genes in A.chinensis,thereby affects its physiological characteristics.This study provides a reference for further researches on drought resistance mechanisms and biosynthesis pathways of main active ingredients in A.chinensis.
The aim of this study was to investigate the expression and distribution of NUPR1 gene in dairy cows with mastitis.To establish a lipoteichoic acid-induced inflammation model of dairy cow mammary epithelial cells(MAC-T)in vitro,the distribution of Nucleus Protein 1(NUPR1)gene in the mammary tissue of diseased dairy cows was determined by immunohistochemistry(IHC).qRT-PCR and WB were used to detect the expression of inflammation-related factors,NUPR1 gene and its upstream and downstream genes in the mastitis tissue and mammary epithelial cell inflammation model of dairy cows.The results were as follows:qRT-PCR and WB results showed that IL-1β,IL-6,IL-8 and TNF-α were significantly up-regulated(P＜0.01)in breast pathological tissues and cell inflammation models.IHC results showed that the expression of NUPR1 in the mammary epithelial cells and diseased mammary tissue of dairy cows was significantly(P＜0.05)or extremely significantly(P＜0.01)higher than that in the normal group,DNMT1 was down-regulated,KLF4,SESN2 and SOCS3 genes were up-regulated(P＜0.01)in the pathological mammary tissue and mammary epithelial cell inflammation model of dairy cows with mastitis.The results provide experimental and theoretical basis for further exploring the regulatory mechanism of NUPR1 gene in the pathological process of mastitis.
To investigate the effects of external addition of carbon(C)and nitrogen(N)on greenhouse gas emission in farmland soil,an indoor incubation experiment was conducted using C(glucose and acetic acid)and N(sulfate ammonium)in farmland black soil at 25℃and flooding condition.Results showed that the combined addition of C and N significantly decreased NO3-content in soil,especially for the combined addition of N and glucose.Compared with the control group without N fertilizer,addition of N had no significant effect on CO2 emission rate.When compared with the group of N fertilizer alone,the combined addition of C and N could stimulate the emission rate of CO2 from soil,with the cumulative emissions of the treatment of N added with glucose and acetic acid were 3.93 and 2.44 times higher than that of the solely N fertilizer group,respectively.Addition of N fertilizer stimulated N2O emission rate,with a value of 3.60 times higher than that of the control group.Furthermore,compared with the control group,the N2O emission rate increased significantly by single application of N fertilizer,and the cumulative emission was 3.60 times higher than that of the control treatment.Compared with N fertilizer alone,nitrogen fertilizer combined with glucose treatment significantly promoted the N2O emission rate only on day 1,and there was no significant difference in the cumulative N2O emission during culture.The effect of nitrogenous fertilizer combined with acetic acid treatment on N2O emission rate lasted for 5 days,and the cumulative N2O emission was 3.58 times higher than that of nitrogenous fertilizer alone.Furthermore,addition of N fertilizer had no significant effect on CH4 emission rate compared with the control group.Compared with the treatment of N fertilizer added alone,combined addition of C and N significantly increased CH4 emission rate and cumulative emissions from soil,but no significant difference was observed for the emissions of CH4 between the treatments of combined addition of N with glucose nor acetic acid.The results indicate that the presence of glucose and acetic may promote greenhouse gas emissions from farmland black soil under short-term flooding condition,and also provide theoretical support for the assessment of greenhouse gas emissions from black soil.
To study the effect of exogenous Uniconazole on physiological parameters of potato leaves under drought stress,a pot experiment was carried out in the potting field of Keshan Branch of Heilongjiang Academy of Agricultural Sciences in 2022 using drought-sensitive variety Atlantic as the experimental material.Uniconazole and drought treatments were carried out during the tuber expansion period(the second inflorescence flowering).Four treatments were set up as follows:normal water management(CK),normal water management + Uniconazole spraying(CK+S),drought stress(D)and drought stress + Uniconazole spraying(D+S).Samples were collected after 15 days of Uniconazole spraying.The effect of exogenous Uniconazole on the growth,active oxygen accumulation,antioxidant enzyme activity,ascorbate-glutathione(ASA-GSH)cycle and osmotic adjustment substance content of potato leaves under drought stress were analyzed by correlation analysis and principal component analysis.Results showed that exogenous Uniconazole could significantly improve the growth of potato leaves.Compared with D treatment,the contents of chlorophyll a(Chl a)and total chlorophyll(Chl a+b)in leaves treated with D+S increased significantly by 16.52%and 13.85%,respectively.Uniconazole spraying reduced MDA,O2-production rate and H2O2 content in leaves,but increased antioxidant enzyme activity and ASA,GSH,DHA and GSSG content in ASA-GSH cycle,result in a removal of excessive accumulation of ROS and reduced membrane lipid peroxidation.In addition,exogenous Uniconazole could significantly increase the content of soluble protein and proline in leaves,and also alleviate the inhibitory effect of drought stress on leaf growth.Furthermore,exogenous Uniconazole can promote the synergistic effect between antioxidant enzymes,ASA-GSH cycle and osmotic regulation in potato leaves,thereby improving the level of reducing power and antioxidant capacity in leaves,reducing the damage caused by reactive oxygen species to cell membranes,and improving potato drought tolerance.This study provides more scientific basis for drought-resistant cultivation of potato and application of Uniconazole.
随着全球农业科技的快速发展,农业科技信息的传播交流愈加重要.英语作为国际通用语言在农业科技领域中扮演着重要的角色.由于农业科技领域的专业性和特殊性,准确地翻译农业科技英语文献成为具有挑战性的任务.语料库是一个包含大量文本样本的电子数据库,可以用于研究和分析语言使用的规律.通过构建农业科技领域语料库,可以收集大量的农业科技英语文献,从而提取出专业术语、短语、句型和语言表达的规律,为农业科技英语翻译提供支持.为了推动语料库的建立,促进农业科技的跨国交流,《2023世界农业科技创新大会》于2023 年11月3日在平谷区金海国际会展中心召开.会议指出,农业科技发展正面向现代化发展,需为全球农业科技创新人才搭建筑梦舞台,而农业科技英语是实现这一目标不可或缺的工具.
农耕是中国农业社会的核心活动,对国家的发展有着深远的影响.中国水墨画以其独特的表现形式,成为表达农耕主题的重要艺术载体.农耕题材的水墨画作品通过描绘农田、农民、农具等元素,展现了中国农耕文化的丰富内涵,还原了农耕社会的劳动场景.艺术家们通过创新的表现手法,诠释着农耕的内涵,使之与现代社会相结合,不仅丰富了农耕题材的表现形式,也促进了中华传统文化的传承与发展.本文主要探讨农耕题材中国水墨画创作方式,为农耕文化传承提供保障,也为我国农业文化遗产的传承奠定基础.
This study aimed to elucidate the effects of combined nitrogen and phosphorus and reduced fertilizer applications on the growth,nutrient utilization,and yield traits of wheat.The research was conducted through a hydroponic experiment and a field positioning experiment from 2019 to 2021,involving eight main wheat varieties cultivated in southern Shanxi.In the hydroponic experiment,four nitrogen and phosphorus treatments(N 0.2 mmol·L-1+P 0.1 mmol·L-1、N 0.2 mmol·L-1+P 2.5 mmol·L-1、N 4 mmol·L-1+P 0.1 mmol·L-1、N 4 mmol·L-1+P 2.5 mmol·L-1)were applied to preliminarily investigate and screen seedling traits of the different wheat varieties.In the field experiment,the effects of reduced fertilizer application on wheat growth and development,nutrient utilization,and yield were examined throughout different years using three treatments,i.e.,conventional fertilization(CF),reduced fertilizer application(FR),and no fertilizer application(CK).Results showed that under hydroponic conditions,the sample Pinyu 8161 had the lowest plant height,root length,plant dry weight,root dry weight,and root-to-shoot ratio among all wheat varieties in terms of the nitrogen and phosphorus levels.Under low phosphorus conditions,the dry weight increase of Liangxing 67 with normal nitrogen was only 17.07%,while the root dry weight decreased.Moreover,the root cap was relatively low under normal nitrogen and phosphorus conditions.In addition,under normal nitrogen and phosphorus conditions,the root cap was relatively low.Under field production conditions,the yields of Pinyu 8012 and Jimai 22 remained high when the fertilizer application reduced from 2019 to 2020(wet year),showing no significant difference in their yields.In contrast,under the same conditions,the yield of Hannong 1412 was the lowest(only 7 520.18 kg·hm-2)among all varieties.Compared to conventional fertilization,the yields were significantly lower in cultivars of Shannong 20,Zhongmai 4072,and Hannong 1412 with reduced fertilizer application.During the period from 2020 to 2021(dry year)when fertilizer was reduced,the yield of Jimai 22(6 191.53 kg·hm-2)was significantly higher than that of Pinyu 8012 and Shinong 086.Jimai 22 also had a high grain nitrogen accumulation(130.35 kg·hm-2)and phosphorus absorption efficiency(0.79 kg·kg-1).Reducing the application of chemical fertilizers in dry years led to early leaf senescence in the later stages of wheat growth,which significantly reduced the dry matter accumulation during maturation but impacted little on stem morphological characteristics.In summary,when 180.0 kg·hm-2 N,105.0 kg·hm-2 P2O5,and 34.5 kg·hm-2 K2O were applied during wheat growth in the wheat-corn rotation region of Jinnan,and N 60.0 kg·hm-2 N was applied during the jointing period,the yields of cultivars Pinyu 8012 and Jimai 22 were higher in the wet year.Jimai 22 also had the highest yield in the dry year,and reducing the chemical fertilizer improved the storage and re-transportation of dry matter in the nutrient organs of wheat before flowering,as well as the grain yield contribution rate and the thickness of the third internode.However,merely reducing continuous fertilizer application in dry years could lead to varying degrees of instability and unsustainability in wheat yield.Overall,the findings of this study provide more strategies for a stable and efficient cultivation in the wheat region of southern Shanxi.
To investigate the effects of physical radiation on three rose cultivars,the indicators of morphological characteristics,mutation rate,death rate,and semi-lethal radiation dose of Carefree Wonder,Beijinghong,and the Golden Scepter were irradiated with 0,10,20,40,60,80 Gy.The results showed that the plant height,crown breadth,number of branches,length of branch,length of compound leaf,and width of compound leaf of three rose cultivars were decreased with the increases of 60Co-γ radiation doses.In detail,Carefree Wonder and Beijinghong showed the best growth when irradiated with 10 Gy,and Golden Scepter grown better under 20 Gy radiation treatment.Otherwise,the death rates were increased along with 60Co-γ radiation doses increased.Lower death rates and more flower color mutants were observed for Carefree Wonder with 10 and 20 Gy treatments respectively.The semi-lethal radiation dose for Carefree Wonder,Beijinghong,Golden Scepter was 53,132 and 19.87 Gy,respectively.The highest mutation rate of Carefree Wonder was 31.67%under 10 Gy radiation,and there were lots of mutants in flower color and flower shape,such as color of white,light pink,soft pink,white and pink.Otherwise,the petal edge of Golden Scepter was mutated from circle edge into serrata edge with 10 Gy radiation treatment,and then turned into deep dehiscence and edge backwinding with 20 Gy treatment.In addition,the number of petals increased significantly for Beijinghong compared with normal.In conclusion,our results indicated that 10 and 20 Gy 60Co-γ rays were conductive to the growth and can induce mutants with new flower color and flower type.This study provided basis for the breeding of Chinese rose.
Different temperature settings in vacuum freeze-drying(FD)procedures affect the sensory and nutritional quality of dried fruit and vegetable products.In order to obtain a better program of blueberry during FD,differential scanning calorimetry was used to explore the changes in the thermodynamic properties and glass transition temperature(Tg)of blueberry,and low field nuclear magnetic resonance was used to determine the water distribution and content changes.With shrinkage,anthocyanin content and texture quality as indicators,the effects of five different heating programs of FD on the crisp drying characteristics and nutritional quality of blueberry were explored.The results showed that there were no significant changes in the eutectic point,eutectic point,and Tg of blueberries after ultrasonic treatment.As the moisture content of blueberries decreased,the Tg increased.The free water in blueberries was first converted into non flowing water,and then non flowing water converted into free water and bound water.The shrinkage rate,color,sensory and nutritional quality of blueberry crispy granules showed significant changes under different program settings(P＜0.05).The shrinkage rate of blueberry crispy granules was the smallest after drying of program 2.The brittleness of blueberry crispy granules was the highest after drying of program 1,and the hardness of blueberry was the highest after drying of program 5;After drying of program 4,△E value for dried blueberries was the highest,while after drying of program 1,vitamin C(Vc)content and antioxidant activity of blueberry crispy granules were the highest.Overall,the superior FD program was program 2.The results of this study provided a theoretical basis for the development of blueberry crispy products.
Tembotrione is a 4-hydroxyphenylpyruvate dioxygenase(HPPD)inhibitor herbicide.Studying the degradation of Tembotrione in aerobic soil is crutial for its environmental safety assessment.This study investigated the main degradation products,degradation pathways,and change pattern of degradation product content with time in aerobic soil by liquid chromatography-high resolution mass spectrometry and other modern analytical methods using high specific activity[phenyl-14C]-Tembotrione as a tracer.Results showed that under aerobic conditions,the degradation of Tembotrione in all the four soil samples followed a first-order kinetic model,and the half-life of Tembotrione in red loam,fluvio-aquic soil,black soil and cinnamon soil was 13.18,5.05,10.49 and 2.82 d,respectively.Three main degradation products(M1,M2 and M3)of Tembotrione were identified in the four aerobic soils,and the degradation pathway in aerobic soil was proposed.,In addition,the content of degradation products in all four soils showed the order of M2(0.5%-60.8%AR)＞M3(0.0-10.0%AR)＞M1(0.0-3.9%AR)during the whole incubation process,except for the 120-day sampling point of fluvio-aquic soil.Overall,this study provides more knowledge for assessing the environmental safety of Tembotrione.
To investigate the prevalence characteristics of"new"Listeria spp.in fruits and vegetables in the field in Hebei province,five types of vegetables and four types of fruits(27 000 samples in total)collected from six major fruit and vegetable farms in Hebei were used to qualitatively analyze of Listeria spp.by using the Listeria spp.detection methods published by China's National Health and Family Planning Commission-China Food and Drug Administration(GB 4789.30-2016),United States Food and Drug Administration-Bacteriological Analysis Manual(FDA-BAM Chapter 10),United States Department of Agriculture(USDA MLG 8.12),and International Standards Organization(ISO 11290-1),respectively,and the plate counting method in GB 4789.30-2016 was followed for the enumeration of Listeria monocytogenes(L.monocytogenes)in positive samples.The results showed that Listeria marthii(0.41%),Listeria thalandensis(0.25%),and Listeria fleischmanni(0.17%)had the highest detection rate,and other 12"new"Listeria discovered in recent years(Listeria newyorkensis、Listeria floridensis、Listeria rocourtiae、Listeria weihenstephanensis、Listeria valentina、Listeria aquatica、Listeria riparia、Listeria cornellensis、Listeria grandensis、Listeria booriae、Listeria costaricensis,and Listeria goaensis)were distributed in different fruits and vegetables in the field.Quantitative analysis showed that the contamination level of L.monocytogenes in most of the positive samples was 0-100 CFU·g-1.It was the first time to conduct a large-scale prevalence distribution study on"new"Listeria in fruits and vegetables in the field,which demonstrated that different"new"Listeria existed in different fruits and vegetables in the field,and the contamination risk of the"classic"Listeria spp.in fruits and vegetables in the field still exists.The results layed a data foundation for further control and prevention of the contamination and spread of the"new"Listeria in fruits and vegetables in the field.
In order to clarify the species of pathogen causing Canarium album black spot in Chaozhou city and screen out effective control agents,this study isolated and purified the pathogens from infected fruits with tissue separation,and then identified the species of pathogen based on morphological and molecular biology.The results showed that Alternaria alternata is the pathogen causing Canarium album black spot.Moreover,the inhibitory effects of 14 fungicides on the growth of Alternaria alternata were evaluated by the mycelial growth rate.The results showed that the growth of Alternaria alternata was significantly inhibited by 14 fungicides.Among which,four fungicides,namely zhongshengmycin 3%WP,captan 80%WG,flusilazole 8%ME and benzoic azoxystrobin 40%SE,showed better inhibitory effects,with inhibitory concentration EC50 of 1.267,1.207,1.100 and 0.944 mg·L-1,respectively.Field trial showed that the prevention effects on Canarium album black spot with benzoic azoxystrobin 40%SE and flusilazole 8%ME were the best,with field control efficiencies of 68.58%and 65.44%respectively,while copper chloride oxide 30%SE and kasugamycin 2%WA exhibited lower field control efficiency(about 10%).In conclusion,benzoic·azoxystrobin 40%SE and flusilazole 8%ME can be recommended as the preferred agents for the prevention and control of Canarium album black spot.This study would provide a theoretical basis for the screening of efficient fungicides against Alternaria alternata as well as prevention and control for Canarium album black spot.
