Research Progress on Detection Techniques of Fungicide Residues in Chinese Chives

Chinese chive is a kind of medicinal and edible plant,with many diseases,and chemical fungicides are usually used for control.In order to find out the risk of pesticide residues in Chinese chives,this paper summarized relevant literatures published in recent years,and sorted out and analyzed the types of pesticides used and detection techniques of common diseases in Chinese chives.

On the calibration of a shear stress criterion for rock joints to represent the full stress-strain profile

Conventional numerical solutions developed to describe the geomechanical behavior of rock interfaces subjected to differential load emphasize peak and residual shear strengths.The detailed analysis of preand post-peak shear stress-displacement behavior is central to various time-dependent and dynamic rock mechanic problems such as rockbursts and structural instabilities in highly stressed conditions.The complete stress-displacement surface(CSDS)model was developed to describe analytically the pre-and post-peak behavior of rock interfaces under differential loads.Original formulations of the CSDS model required extensive curve-fitting iterations which limited its practical applicability and transparent integration into engineering tools.The present work proposes modifications to the CSDS model aimed at developing a comprehensive and modern calibration protocol to describe the complete shear stressdisplacement behavior of rock interfaces under differential loads.The proposed update to the CSDS model incorporates the concept of mobilized shear strength to enhance the post-peak formulations.Barton’s concepts of joint roughness coefficient(JRC)and joint compressive strength(JCS)are incorporated to facilitate empirical estimations for peak shear stress and normal closure relations.Triaxial/uniaxial compression test and direct shear test results are used to validate the updated model and exemplify the proposed calibration method.The results illustrate that the revised model successfully predicts the post-peak and complete axial stressestrain and shear stressedisplacement curves for rock joints.

Detection and Analysis of Pesticide Residues in Chinese Chives and Risk Assessment of Dietary Intake

[Objectives]This study was conducted to understand the status of pesticide residues and dietary intake risk of Chinese chives in Tangshan area. [Methods] Sixty eight kinds of pesticide residues in 415 Chinese chive samples collected from Tangshan area were qualitatively and quantitatively determined by high-performance liquid chromatography-tandem mass spectrometry(HPLC-MS/MS) and gas chromatography(GC) in 2020. [Results] The results showed that 41 kinds of pesticide residues were detected in the 415 Chinese chive samples, and the detection rate was 69.4%(288/415), and there was a combination of pesticides in many samples. According to the National Food Safety Standard―Maximum Residue Limits of Pesticides in Food(GB 2763-2019), the residues of 12 pesticides exceeded the maximum residue limits(MRLs), and the unqualified rate was 38.07%(158/415). The highest detection rate of clothianidin was 41.20%(171/415), but there was no MRL in GB 2763-2019. The next was procymidone, the detection rate of which was 35.42%(147/415), and the over-standard rate was 30.12%(125/415). Forbidden and restricted pesticides were detected in some samples. According to the dietary exposure risk assessment, the NEDI/ADI values were all less than 1 and the intake risk was within acceptable range. In Tangshan area, the types of pesticides used in Chinese chive production are complex, and there are risks of multi-residue pollution and use of banned and restricted pesticides and unregistered pesticides. It is suggested that routine monitoring of pesticide residues and management of pesticide use should be strengthened to ensure the quality and safety of agricultural products. [Conclusions] This study provides a theoretical basis for the safe production of Chinese chive and the standardized and rational use of pesticides.

Main Problems and Countermeasures of Chinese Chive Quality and Safety in China

In recent years,the problem of pesticide residues in Chinese chives has attracted widespread attention from society.This paper comprehensively analyzed the production and planting situation,quality and safety status and changes in pesticide standards of Chinese chives,and deeply discussed the main quality and safety problems of Chinese chives and their causes.On this basis,it was proposed to improve the quality and safety level of Chinese chives from three aspects:improving limit standards,promoting green production prevention and control techniques,and strengthening supervision on input products.

香葱伴生番茄对青枯病及根际微生态特征的影响

【目的】为明确香葱伴生对番茄青枯病及根际微生态特征的影响,揭示香葱伴生番茄降低青枯病发病率的机理。【方法】通过田间试验设置番茄单作和香葱伴生番茄2个处理,分别采集单作发病番茄(QK)、单作健康番茄(NBS)和香葱伴生番茄(BS)的根际土壤,应用16S rDNA高通量测序和液相色谱-质谱联用(LC-MS)技术,探究香葱伴生对番茄根际微生态特征的影响。【结果】田间试验结果表明,番茄单作处理和香葱伴生番茄处理的青枯病平均病株率分别为50.48、31.43%,香葱伴生番茄处理对番茄青枯病的防治效果为37.74%。16S rDNA高通量测序结果表明,BS、NBS根际土壤细菌群落相对丰度和多样性均显著高于QK;与QK相比,BS和NBS根际土壤细菌茄科雷尔氏菌属相对丰度显著降低,而芽孢杆菌属相对丰度升高;与NBS相比,BS根际土壤细菌茄科雷尔氏菌属相对丰度降低,芽孢杆菌属相对丰度显著提高。利用LC-MS技术共鉴定出番茄根际土壤代谢物586种,其中正离子模式代谢物320种,负离子模式代谢物266种,并将代谢物的功能注释至新陈代谢、遗传信息加工和环境信息加工等代谢通路;与NBS相比,BS根际土壤代谢物中的缬氨酸、L-天冬酰胺和柠檬酸的含量均显著降低,L-赖氨酸、谷氨酸、D-谷氨酰胺和异亮氨酸的含量也低于NBS,但差异未达到显著水平。【结论】香葱伴生番茄显著降低番茄青枯病田间发病率,改变了番茄根际土壤中细菌群落结构和番茄根际土壤代谢物含量。

北方草莓温室后墙韭菜管道无土栽培技术

为了提高北方草莓日光温室空间利用率和经济效益,开展了后墙立体栽培韭菜的关键技术研究应用。通过栽培管道安装布设、无土栽培基质填充、韭菜品种优选、科学水肥调控等措施,在京郊草莓采摘季同期可收6茬韭菜,不仅美化了温室环境,丰富了采摘内容,而且提高了温室空间利用率,相当于增加土地面积60m^(2),每年可增加收入6000多元。

枳实薤白桂枝汤防治心血管疾病的研究进展

心血管疾病是严重危害人类健康的疾病之一,目前在我国患病率日益增加,给家庭与社会带来了沉重负担。枳实薤白桂枝汤为治疗“胸痹心痛”的经典名方之一,全方共奏通阳散结、祛痰下气之效。研究发现,枳实薤白桂枝汤治疗心血管疾病临床疗效显著,且该方可通过多靶点、多机制协同作用干预心血管疾病的发生与发展,发挥保护心肌细胞、改善心肌细胞功能等作用。本文就近几年枳实薤白桂枝汤对心血管疾病的临床研究与作用机制进行梳理,为推进枳实薤白桂枝汤的临床应用提供可靠依据。

不同日照时长对韭菜抽薹的影响

为明确不同日照时长对韭菜抽薹的影响,筛选适宜抑制韭菜抽薹的日照时间,以深休眠韭菜品种海韭6号为试验材料,设置自然光照(CK)、9 h、10 h、11 h和12 h 5个日照时长,研究不同日照时长对韭菜抽薹的影响。结果表明,适当缩短日照时长可显著抑制韭菜抽薹,其中10 h和11 h日照下韭菜抽薹率最低,分别为0.66%、0.34%;9 h和12 h日照下韭菜抽薹率分别为8.47%、3.31%;花芽分化解剖学观察结果也表明,适当缩短日照时间可有效抑制韭菜花芽分化。本研究结果可为提高河北张家口等高海拔冷凉地区夏季韭菜产量和品质提供参考。

论综合档案馆档案资源体系建设的长期主义

长期主义本质上倡导为追求长远目标实现而开展决策实践或付诸行动,为综合档案馆档案资源建设提供了价值取向和方法指导。档案价值论、档案治理理论、“成本—收益”理论和WSR系统方法论为长期主义应用于综合档案馆档案资源建设廓定了理论框架。基于长期主义的核心要素,借鉴WSR系统方法论框架,提出综合档案馆在档案资源建设中应当践行长期价值主义,明晰档案资源建设应然目标;践行长期行动主义,谋求档案资源建设效能提升;践行长期激励主义,积极探寻人本价值精神彰显。

微酸性电解水对采后香葱抑菌特性及贮藏品质的影响

为探究微酸性电解水(slightly acidic electrolyzed water,SAEW)对香葱采后贮藏品质的影响,本实验分析低温((4±1)℃)贮藏条件下不同质量浓度(0、100、200 mg/L和300 mg/L)SAEW浸泡处理5 min后香葱采后抑菌特性及贮藏品质的变化。结果显示,较对照和其他质量浓度(100 mg/L和300 mg/L)SAEW处理相比,200 mg/L SAEW浸泡处理更好地维持了采后香葱的外观品质并抑制了其菌落总数的增长。进一步的研究结果显示,200 mg/L SAEW浸泡处理可有效抑制香葱中质量损失率和腐烂率的增加,减缓叶绿素、VC、可溶性糖以及可溶性蛋白含量的下降,减少有害物质总游离氨基酸、丙二醛和亚硝酸盐的积累。综上,200 mg/L SAEW浸泡处理不仅能有效抑制低温贮藏期间香葱中菌落总数的增长,而且可有效延缓该过程中香葱营养品质的流失,从而提高香葱的保鲜效果。因此,SAEW可作为一种维持采后香葱贮藏品质,延缓其衰老进程的有效杀菌、保鲜措施。

韭菜联合收获机的设计与试验

针对当前韭菜机械化收获存在的割茬不齐、铺放乱序及人工归集打捆效率低等问题,结合韭菜物理特性及国内韭菜种植模式,设计了一种集喂入切割、夹持输送、有序铺放及归集打捆于一体的韭菜联合收获机。整机采用电动自走式结构,重点设计了扶禾喂入装置、切割装置、夹持输送铺放装置、集束与打捆装置等关键工作部件的结构参数。构建了韭菜收获打捆试验台,开展了韭菜收割打捆试验,结果显示:收获齐茬率93.1%,损伤率2.6%,损失率1.8%,收获机能够较低损伤、较高质量地完成韭菜齐茬收割、有序输送和集束打捆的联合收获,各性能参数达到了设计要求。

不同厚度聚乙烯薄膜对韭薹低温贮藏品质的影响

为建立冷藏条件下韭薹自发气调包装(MAP)保鲜方法,将新鲜预冷的韭薹(200±0.5)g密封包装于25 cm×60 cm的聚乙烯(Polyethylene,PE)薄膜包装袋内,薄膜厚度分别为10、20、25、30、45μm,于(0±0.5)℃下贮藏105 d,研究不同O_(2)和CO_(2)透过率的薄膜对韭薹贮藏过程中包装袋内O_(2)和CO_(2)体积分数及产品品质的影响。结果表明,不同O_(2)和CO_(2)透过率的聚乙烯薄膜包装处理都可以很好地抑制韭薹品质劣变;不同处理组之间袋内O_(2)和CO_(2)的体积分数均存在显著差异(P<0.05);45μm PE袋(O_(2)透过率(4080±352)cm^(3)·m^(-2)·d^(-1)·0.1 MPa^(-1)、CO_(2)透过率(16566±1415)cm^(3)·m^(-2)·d^(-1)·0.1 MPa^(-1))处理的前15 d袋内O_(2)体积分数显著下降,之后维持在3.94%~6.66%(第105天除外),前60 d袋内CO_(2)体积分数显著下降,之后维持在3.07%~3.53%之间,该处理有效地抑制了韭薹黄化、花苞开放及花苞腐烂,贮藏至105 d时,纤维素含量维持在较低水平,韭薹仍然具有商品价值。综上,采用聚乙烯薄膜包装可以保持韭薹低温贮藏的商品性,延长其货架期。

韭菜新品种久星31号的选育

久星31号是以天津青韭优选株系96-13-32为母本,以92-1优选株系19-5-6为父本,经有性杂交、系统选育而成的韭菜新品种。直立性强,春季返青早,平均株高49.0 cm,假茎长10.1 cm、粗0.6 cm;叶片深绿色,蜡粉少,长宽条形,先端锐尖,平均叶长38.9 cm,叶宽0.8 cm,单株功能叶片数5片,单株质量8.7 g;分蘖能力强,冬季不休眠,耐寒性强,对灰霉病的抗性强于对照791,蛋白质含量1.82%,β-胡萝卜素含量9.10μg·g^(-1),VC含量216.0 mg·kg^(-1),铁含量71.1 mg·kg^(-1);年收割6~7茬,每667 m^(2)产量12500 kg左右,适宜河南省以及生态型相似地区种植。

浙江省韭菜中常用杀菌剂多残留分析及膳食暴露风险评估

评估浙江省内生产基地与市场环节韭菜的杀菌剂残留水平及对人体的膳食暴露风险。采集时间主要集中在2020年12月至2021年1月,2021年8月至2021年11月,连续两年对浙江省内采集的213个韭菜样品中39种杀菌剂进行残留检测分析,并对检出杀菌剂进行急性和慢性膳食暴露风险评估。残留杀菌剂共19种,总检出率为48.83%(104/213),其中腐霉利(15.02%)、多菌灵(13.15%)、啶酰菌胺(13.15%)、烯酰吗啉(11.74%)、吡唑醚菌酯(11.27%)、百菌清(10.80%)检出率较高;检出2种及2种以上杀菌剂残留的样品占总样品量的25.82%(55/213)。1个样品中的嘧霉胺残留量超过了农业农村部规定的鳞茎类蔬菜最大残留限量(3 mg/kg),超标率为0.47%,样品合格率达99.53%。该实验韭菜中腐霉利按现有标准GB 2763.1-2022(5 mg/kg)判定,则无样品超标,但依据原有标准GB 2763-2021(0.20 mg/kg),腐霉利超标率达7.04%(15/213)。急性和慢性风险范围分别为0.004%~5.546%和0.000%~9.654%,均小于1,摄入风险处在可接受水平。该结果说明浙江省内韭菜中农药多残留情况较突出,应加强农药使用管理,确保韭菜消费安全。

施氮量对有机基质栽培韭菜生长、品质及氮素利用的影响

为筛选适宜有机基质栽培韭菜生长的最佳施氮量,以独根红品种为试材,设置CK(0 kg·667 m^(-2))、T1(4 kg·667 m^(-2))、T2(8 kg·667 m^(-2))、T3(12 kg·667 m^(-2))、T4(16 kg·667 m^(-2))、T5(20 kg·667 m^(-2))、T6(24 kg·667 m^(-2))、T7(28 kg·667 m^(-2))、T8(32 kg·667 m^(-2))、T9(36 kg·667 m^(-2))共10个尿素处理,探究施氮量对基质栽培韭菜生长、品质及氮素利用的影响。结果表明,T3处理的韭菜总产量最高,较CK、T9处理分别显著增产21.58%、17.19%,分蘖数较CK显著增加37.69%。T3处理有较好的根系形态,且分蘖数、根系形态及矿质养分含量之间存在不同程度的正相关性(r=0.352~0.952)。氮肥农学效率、偏生产力和氮素利用率随施氮量的增加整体上呈降低趋势。采用隶属函数法对产量及可溶性糖、丙酮酸、纤维素和硝酸盐含量等指标进行综合评价,T3处理得分最高,综合品质最好。综上,适宜的施氮量能提高韭菜的产量、品质,促进矿质养分的吸收,其中T3处理能较好地协调产量、品质和氮肥利用率的关系,效果最佳。

不同韭菜品种营养品质评价分析

为充分利用韭菜资源,筛选营养品质较高的韭菜品种,对7个青韭品种、3个韭黄品种共10个样品进行营养品质评价分析,测定氨基酸、可溶性淀粉及矿物质含量等13项营养品质指标,运用差异显著性分析、相关性分析、主成分分析、聚类分析和模糊隶属函数分析法对韭菜营养品质进行综合评价。结果表明:10个样品的13项营养品质指标差异显著,系统聚类分析将10个样品分为3类。第Ⅰ类为20-CJ37-1、20-CJ36-1、20-CJ17、20-CJ38;第Ⅱ类为21-CJ43、20-CJ37、20-CJ8、20-CJ26、20-CJ38-1;第Ⅲ类为20-CJ1。主成分分析提取了韭菜品质综合评价的3个主成分,获得总游离氨基酸、可溶性淀粉、含水量、可溶性蛋白、热值5个营养品质评价指标。通过模糊隶属函数模型分析表明20-CJ17、20-CJ36-1、20-CJ26的营养品质较高。

Effect of Chitosan with Different Molecular Weights on Postharvest Quality of Chinese Chive Scapes

[Objective] The purpose of this study was to determine the effect of chitosan with different molecular weights on quality and lignification of postharvest Chi- nese chive scapes （Allium tuberosum Rottler ex Sprengel）. [Method] Some physio- logical and biochemical indexes such as weight loss, decay index, opening rate of flowers, chlorophyll and ascorbic acid content, respiration rate, the activities of enzymes, lignin and cellulose content of Chinese chive scapes treated with three kinds of chitosan with different molecular weights were investigated during the room stor- age at 20 ℃ to simulate shelf life. [Result] The results showed that all the treat- ments of chitosan with different molecular weights significantly delayed weight loss, decay index and opening rate of flowers, maintained higher chlorophyll and ascorbic acid content, inhibited respiration rate, reduced the activities of enzymes phenylala- nine ammonia lyase, cinnamyl alcohol dehydrogenase and peroxidase, and retarded lignin and cellulose accumulation during the storage of Chinese chive scapes. However, high molecular weight chitosan has better preservation effect on Chinese chive scapes. [Conclusion] The results suggest that the coating treatment of high molecu- lar weight chitosan may be a promising technique to maintain postharvest quality of Chinese chive scapes.

Comparison of Methods for Ultra-drying of Chinese Chive Seeds

[Objective] This study aimed to identify the ultra-drying method most suitable for the storage of Chinese chive seeds through comparing different ultra-drying meth- ods. [Method] Through setting treatments including freezing, silica gel drying and heating drying at 50℃ as well as two controls, the effects of different drying methods for storing ultra-dried Chinese chive seeds were compared. [Result] There were no significant differences in the germination rate and seedling length between Chinese chive seeds treated with heating drying at 50℃ and those treated with either freezing or get drying at the initial stage of the storage. Storing of Chinese chive seeds previously treated with either heating drying at 50℃, or freezing or gel drying for 0-98 months at 20℃ hadn＇t caused any adverse effect on the germination rate of seeds. And the effect of different storage conditions on seedling length displayed earlier than that on the germination rate. There was no significant difference on seedling length between seeds treated with heating drying at 50℃ and those treated with freezing drying after stored for as long as 98 months, revealing similar efficacy on storing seeds. [Conclusion] Freezing drying requires huge investment and cost for perennial running, and silica gel drying is slow in drying and time-consuming. By contrast, heating drying at 50℃ is an economic and simple method, which can enable the Chinese chive seeds to sustain a longevity of eight years or more.

相生和相克间作作物对豌豆根际微生物群落的影响

【目的】解析豌豆与相生和相克作物间作其根际微生物群落的组成,探讨作物间发生相互抑制和协同效应的微生物学机制。【方法】盆栽试验设置4个处理:碗豆间作番茄(PT,相生),间作香葱(PA,相克),单作(PP),以不种植作物的处理为对照。供试土壤为红壤土。作物定植50天时,挖出整株植物,通过抖落法采集根际土壤,基于高通量测序技术比较分析豌豆根际土壤中细菌与真菌群落结构。【结果】间作番茄(PT)处理豌豆根际土壤微生物生物量磷(MBP)显著高于间作香葱(PA)和碗豆单作(PP)。相生或相克组合间作均提高了豌豆植株根际土壤细菌和真菌各分类水平的数量,并且细菌多样性和丰富度均发生显著变化。间作诱导豌豆植株根际土壤细菌和真菌群落组成发生显著变化,间作香葱诱导糖单孢菌属(Saccharomonospora)和硫杆菌属(Thiobacillus)等具有分泌抑制豌豆生长化感物质潜力的细菌,以及作为病原菌的镰刀菌属(Fusarium)真菌富集在豌豆植株根际。与之相比,间作番茄虽然对豌豆根际细菌和真菌群落多样性与丰富度影响较小,但显著改变了豌豆根际细菌和真菌的群落组成;另一方面,豌豆间作相生作物—番茄不仅诱导油壶菌属(Olpidiom)真菌富集,而且降低了镰刀菌属(Fusarium)等病原真菌的相对丰度。【结论】与相生作物间作,可提高豌豆根际土壤中的微生物磷含量;而与相克作物间作,诱导豌豆根系招募分泌抑制豌豆根系生长的化感成分的有害微生物以及致病菌,这可能是作物相克的重要原因。

胶体金免疫层析法在韭菜农药残留检测中的应用研究

为验证胶体金免疫层析技术在韭菜农残检测中的可靠性和适用性,选用3种不同的农残胶体金免疫层析快速检测产品(胶体金农残快检试剂)检测韭菜中腐霉利、吡虫啉、啶虫脒、多菌灵、克百威、三唑磷等6种农药残留,并将其与色谱质谱串联法进行比较,对其灵敏度、假阳性率及假阴性率进行验证评价。结果表明,在0.5 LOD的农药添加水平下,3种胶体金农残快检试剂对实验室空白样品的检测结果均为阴性;但当添加水平达到LOD或MLR时,其检测结果均为阳性,证明胶体金农残快检试剂灵敏度较高,且符合国家标准食品中农药最大残留限量要求;实验室加标试验和实际样品比对试验结果显示,胶体金农残快检技术与色谱质谱联用法的检测结果均无显著性差异(χ^(2)<3.84),其假阴性率和假阳性率均为0。故胶体金免疫层析法可在韭菜的农残快速检测中应用。