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甲霜灵在西瓜及土壤中的残留消解动态研究 总被引：1，自引：0，他引：1
采用高效液相色谱检测方法,研究甲霜灵在西瓜及土壤中2a的残留消解动态及最终残留。结果表明:甲霜灵在西瓜和土壤上的半衰期为4.10~4.30 d和8.61~9.55 d。甲霜灵灌根施药后,西瓜全果经过14 d,土壤经过28 d,消解率都达到85%以上。按最高推荐剂量500 g.a.i/hm2和1.5倍高剂量750 g.a.i/hm2使用3~4次,收获距末次施药间隔5、7、14 d,甲霜灵在西瓜全果、瓜肉和土壤中的最终残留量均低于中国食品中甲霜灵的最大残留限量标准0.2 mg/kg。所以甲霜灵在海南地区西瓜上按照推荐剂量300~500 g.a.i/hm2灌根2~3次,采摘间隔期7 d以上是安全的。 相似文献
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采用气相色谱法及田间试验方法,研究马拉硫磷在香蕉和土壤中的残留降解动态。结果表明:马拉硫磷在香蕉上的原始沉积量与施用剂量密切相关,加倍剂量的原始沉积量比推荐剂量的高出80.2%,两种处理的降解速率均非常迅速,施用后7 d残留量均0.005 mg/kg。马拉硫磷在香蕉园土壤上的降解规律符合一级动力学关系,降解动态方程为C=0.096 3·e-0.118 4 t,半衰期(T1/2)为5.5 d,降解99%所需要的时间(T0.99)为35.9 d。距第2次施药后61~65 d,最终在香蕉及土壤上均未检出马拉硫磷残留(检出限为0.005 mg/kg)。在福建蕉区上科学、合理施用马拉硫磷,最终产品质量可符合GB 2763-2012、NY/T 750-2011中规定的MRL要求,同时最终对蕉园土壤环境不会造成长期污染。 相似文献
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建立了豇豆、土壤中吡虫啉测定高效液相色谱法,并研究吡虫啉在海南豇豆和其种植土壤中的消解动态以及在豇豆中的最终残留。结果表明:方法回收率为78%~89%,在0.05~5μg/mL线性关系良好,相对标准偏差(RSD)7%,最低定量限0.01μg/mL,方法满足检测工作要求。吡虫啉在豇豆和土壤中的半衰期分别为2.9、5.1 d。以1.5倍推荐剂量一次喷施农药2.5 d后吡虫啉残留量小于0.5μg/g。吡虫啉在土壤中半衰期较短,属于易降解农药;分别以1.5、2倍推荐剂量3次施药,每次施药间隔2d,自然降解4、6d后残留量均低于0.5μg/g。 相似文献
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敌敌畏、溴氰菊酯、三氟氯氰菊酯在香蕉上的残留动态 总被引：2，自引：0，他引：2
采用气相色谱法及田间试验方法,研究敌敌畏、溴氰菊酯、三氟氯氰菊酯在香蕉上的残留动态。结果表明,在香蕉上的原始沉积量,敌敌畏>溴氰菊酯>三氟氯氰菊酯,同一农药的原始沉积量与施用量密切相关。敌敌畏在香蕉上消解迅速,在施药1 d后消解率均在80%以上,施药后3 d的残留量≤0.005 mg/kg。溴氰菊酯、三氟氯氰菊酯在香蕉上的残留消解动态符合一级动力学方程,溴氰菊酯推荐剂量为C=0.129 8×e-0.1201t,加倍剂量为C=0.248 9×e-0.114 5t,半衰期(T1/2)为5.8～6.1 d,消解99%所需要时间(T0.99)为38.4～40.3 d;三氟氯氰菊酯推荐剂量为C=0.033 9×e-0.070 0t,加倍剂量为C=0.070 7×e-0.069 5t,T1/2为9.9～10.0 d,T0.99为65.8～66.3 d。敌敌畏、溴氰菊酯、三氟氯氰菊酯在距第2次(末次)施药后60～70 d,香蕉产品的最终残留量均分别<0.005 mg/kg、<0.01 mg/kg、<0.008 mg/kg。 相似文献
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对比了香蕉果穗不套袋、断蕾后套袋、全程套袋三种不同套袋方式下戊唑醇在香蕉全果和果肉中的残留情况。按推荐施药剂量和推荐施药剂量1.5倍施用3次和4次250 g/L戊唑醇水乳剂,末次试药距收获期42 d时,不套袋处理的最终残留量均高于戊唑醇在香蕉上的最大残留限量0.05 mg/kg,断蕾后套袋的最终残留量均低于0.05 mg/kg,全程套袋的最终残留量均低于最低检测浓度0.025 mg/kg。香蕉套袋可以有效阻挡农药在蕉果上的附着,从而降低戊唑醇在香蕉上的残留量。 相似文献
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采用气相色谱（GC-ECD）及田间试验方法,研究了溴虫腈在菜用大豆中的残留消解动态和安全使用技术。结果表明,溴虫腈在菜用大豆上的原始残留沉积量因不同施药处理而有所差异。其残留消解动态符合一级动力学关系,相关系数（︱r︱）=0.9438-0.9847（P〈0.01）;早季的消解系数（︱k︱）=0.13555±0.001955,半衰期（T1/2）为5.0-5.2 d,消解99%所需要的时间（T0.99）为33.5-34.5 d;晚季的︱k︱=0.12748±0.00268,T1/2为5.3-5.6 d,T0.99为35.4-36.9 d。按常规施药方法,在菜用大豆上施用溴虫腈（112.50 g·hm^-2）,在施药1次后17 d,早季豆的农药最终残留量为0.448 mg·kg^-1,晚季豆的农药最终残留量为0.519 mg·kg^-1;连续施药2次（间隔7 d）后22 d,早季豆的农药最终残留量为0.459 mg·kg^-1,晚季豆的农药最终残留量为0.536 mg·kg^-1,产品质量安全水平均符合美国规定的最高残留限量标准。 相似文献
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毒死蜱在菜用大豆上残留动态及安全使用技术 总被引：4，自引：0，他引：4
为了监测菜用大豆中毒死蜱的残留量及科学、安全使用毒死蜱防治菜用大豆上的害虫,确保产品质量安全,采用气相色谱法及田间试验方法,研究了毒死蜱在菜用大豆上的残留消解动态,并对其安全使用技术进行示范试验.结果表明:毒死蜱在菜用大豆上的原始沉积量较高,施用有效成分1.08 kg·hm-2的原始沉积量高于施用0.77 kg·hm-2,施用2次的高于施用1次.毒死蜱在菜用大豆上的残留消解动态均符合一级动力学方程,早季的消解速率快于晚季,早季的半衰期(DT50)为2.7 d,消解99%所需要的时间(T99)为18.2 d,而晚季的DT50为3.43.5 d,T99为22.7-23.5 d.安全使用技术示范试验结果显示,毒死蜱按常规使用剂量及施药方法,间隔7 d连续施用2次,施药后25 d、28 d的残留量平均分别为0.075 mg·kg-1和0.030 mg·kg-1,对照GB2763·2005中叶菜类蔬菜的MBL,以及日本、美国、欧盟的MRL,毒死蜱在菜用大豆上施药后25 d产品符合于我国的质量安全要求,28 d产品符合于日本、美国、欧盟规定的质量安全要求. 相似文献
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A total of 134 Czech Pseudoperonospora cubensis isolates originating from Cucumis sativus were used for fungicide resistance screening. Efficacy of six commonly used and registered fungicides was screened in Czech P. cubensis populations. The investigations covered the frequency and occurrence of sensitive, moderately resistant and resistant isolates to the individual fungicides during the period 2005–2010. Fosetyl-Al (Aliette 80 W) and propamocarb (Previcur 607 SL) were the most effective fungicides. All tested isolates were sensitive on all tested fosetyl-Al concentrations. However, some isolates expressed resistance (profuse sporulation) or moderate resistance (limited sporulation) to lower and/or even to recommended concentrations of propamocarb in the years 2006 and 2008–2010. Metalaxyl (Ridomil PLUS 48 WP) and metalaxyl-M (Ridomil Gold MZ 68 WP) were ineffective. Isolates collected in 2008 and 2009 showed large variation in moderate resistance or resistance even at high fungicide dosages. However, this result was not confirmed in 2010, when efficacy of these fungicides increased slightly, and 69% and 43% of isolates were controlled at the recommended concentration of metalaxyl-M and metalaxyl, respectively. Limited or profuse sporulation was observed only sporadically at high concentrations. Sensitivity of isolates to cymoxanil (Curzate K) differed among the studied years. While cymoxanil was ineffective in the years 2005–2008 and in 2010, 68% of isolates were controlled at the recommended concentration in 2009. During the years 2005 through 2010, a shift towards higher sensitivity to dimethomorph was observed at all screened concentrations. 相似文献
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为了研究番茄NAM基因的功能,利用RT-PCR技术从番茄cDNA中分离了NAM(GenBank登录号:FJ435163.1)基因,该基因ORF全长1 053 bp,共编码351个氨基酸,N端含有NAC结构域.定量RT-PCR分析结果表明,该基因在番茄的根、茎、叶、花和果实中均有较强表达.为了进一步研究番茄NAM基因的功能,构建了NAM基因的超表达载体pLP100-35S-NAM,通过农杆菌介导法转化番茄,并获得抗性植株.经表型分析,转基因番茄植株矮小,生长受到抑制,叶片形态异常,表明NAM基因影响番茄顶端分生组织(SAM)的形成和叶片形态的发生. 相似文献
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利用PCR技术从番茄基因组DNA中扩增了Sly-miR167a转录起始点上游2 134 bp的片段,并将其与GUS基因融合构建植物表达载体,转化番茄,研究番茄Sly-miR167a启动子的时空表达特异性;并利用外源激素处理,研究其对激素的响应特性。启动子序列分析结果表明,Sly-miR167a启动子片段含有启动子调控的保守序列以及生长素、乙烯和赤霉素等响应元件。根据GUS染色结果推测,Sly-miR167a可能在番茄的各个组织中均有表达,并且在叶片、茎、开花前2d、开花当天、果实幼果期、绿熟期和破色期表达强烈。通过外源激素处理后,GUS基因的表达均有显著的上调。说明Sly-miR167a启动子的表达具有时间特异性,并且受外源激素的调控。 相似文献
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Xanthomonas axonopodis pv. vesicatoria was isolated from infected tomato seedlings grown in an open field in Egypt. All the tested isolates infected tomato plants but with different degrees of disease severity. In an attempt to manage this disease, tomato seeds and/or seedlings were treated with an antagonistic local isolate of Pseudomonas fluorescens as a suspension or its formulation or acibenzolar-S-methyl (BTH). When the above three treatments were applied to tomato seeds under laboratory conditions, they improved seed germination and seedlings vigour relative to control seeds treated with sterile distilled water and pathogen but P. fluorescens culture was the most effective. Under greenhouse and field conditions, combinations of the above treatments were used. All treatments significantly reduced disease severity of bacterial spot in tomato relative to the infected control. The biggest disease reduction compared to seedlings inoculated with the pathogen alone resulted from a foliar application of P. fluorescens. Combined application of P. fluorescens or its formulation with BTH reduced the pathogen population and increased seedling biomass and tomato yield relative to control seedlings. 相似文献
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采用改良的海藻糖电转化法获得GFP标记菌株X5-GFP、BQA2-GFP,显微镜观察标记菌株在土壤和水培中的番茄根际的定殖情况。结果表明:标记菌株单独或与青枯菌先后加入进行处理,番茄根际标记菌株的种群数量变化趋势都是一致的。在土壤番茄根际中,X5-GFP单独处理后当天的菌量为1.05×106CFU/g,随之菌量逐渐下降;处理30 d后,为1.50×10~3CFU/g;而BQA2-GFP单独处理后当天菌量为1.68×106 CFU/g,随之菌量也逐渐下降;处理30 d后,为2.50×10~3CFU/g;在水培番茄根际中,X5-GFP单独处理后当天的菌量为2.70×10~5CFU/g,随之菌量逐渐下降;处理30 d后,为1.00×10~3 CFU/g;而BQA2-GFP单独处理后当天菌量为3.60×10~5CFU/g,随之菌量同样逐渐下降;处理30 d后,为1.50×10~3 CFU/g。这表明解淀粉芽胞杆菌X5、BQA2均在番茄根际有较强的定殖能力。 相似文献
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Use of tomato crop residues into soil for control of bacterial wilt caused by Ralstonia solanacearum
Tomato debris can be used as the soil amendment to reduce agricultural residue accumulation problems and increase soil fertility. However, pathogens present in the debris may form a risk for subsequent crops. In this study, tomato growth substrate was amended with tomato debris artificially inoculated with Ralstonia solanacearum and the effect of heat treatments on the survival of the pathogen was measured. Experiments were carried out in the laboratory and in greenhouses, using peat moss and sand mix in pots as substrates. Pots were enclosed in plastic bags or left open. Then 0, 5, 10 and 15 g of tomato debris were applied to 500 g growing medium, with four replicates per treatment. Treatments at 45 °C lowered tomato wilt indices in tomato cv. Money-Maker and that the pathogen was not eradicated after pot treatments at 25 °C. R. solanacearum remained pathogenic on the assayed growing media after a six-week treatment at 25 °C, but was eradicated after treatments at 45 °C. The lower infectivity of infected debris tomato plants when buried with high doses of organic matter and at temperatures above 45 °C suggests that adverse effects on the soil inoculum would be exerted through increased soil temperatures. This study demonstrates that tomato crop residues, usually considered waste material, could be used as soil amendments to reduce their effect as a source of contamination as they offer additional advantages. 相似文献
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《Journal of Crop Improvement》2013,27(2):313-321
Summary The allelopathic effects of chemical substances released from the tomato plant (Lycopersicon esculentum Mill.) were investigated on various receptor plants. Bioassays under controlled conditions in a growth chamber showed that germination and seedling growth of Lactuca sativa and growth of Vitis were reduced when grown near tomato plants. It was also observed that when plants were grown in a U-tube pot with tomato plant, the tomato roots excreted allelochemicals that inhibit growth of tested species. To identify the phytotoxic compounds from tomato plant, a GC/MS method was employed. Forty compounds, such as trans-2-hexenal, a-terpineol, linalool, phenylace-taldehyde, methylsalicylic acid and tetradecanoic acid were identified from the essential oil of tomato plants. The volatile substances from leaves inhibited seed germination and seedling growth of receptor plants in laboratory tests. Inhibitory response varied with the concentration of compounds. These findings suggest that the tomato plant may have an interesting allelopathic potential. 相似文献