HPLC检测分析噻虫嗪种衣剂在马铃薯中的残留动态变化

为明确马铃薯种薯包衣播种后活性成分噻虫嗪在植株和薯块上的残留动态,评价噻虫嗪种衣剂的使用安全性,建立其在马铃薯植株和薯块上的残留检测方法。采用田间试验和高效液相色谱法,样品经甲醇超声提取,浓缩净化后,通过HPLC-UVD检测,外标法定量。添加回收率实验结果表明：该方法在马铃薯植株及薯块上添加回收率分别为86.73%~92.58%、86.03%~93.35%,相对标准偏差(RSD)分别为3.46%~8.19%、3.65%~6.22%,最低检出量为1.0×10-9 g,最低检测浓度为0.001 mg/kg,符合农药残留检测要求。残留动态实验结果表明：噻虫嗪种衣剂在马铃薯植株中的残留动态符合一级动力学方程,包衣播种后60天,噻虫嗪在马铃薯植株中的残留量高,为33.975 mg/kg,以此为原始沉积量得到半衰期为12.4天。在马铃薯块茎中未检测到噻虫嗪。     

高效液相色谱法测定茶叶中的5种农药残留

建立高效液相色谱法检测茶叶样品中5种农药残留分析方法,以期为茶叶绿色生产提供技术理论支撑。样品经水浸泡后,用正己烷和丙酮混合液(V:V=5:1)振荡提取,乙酸乙酯萃取,经弗罗里硅土和活性炭层析柱净化后,高效液相色谱检测茶叶中5种农药（高效氯氟氰菊酯、氯氰菊酯、联苯菊酯、噻虫嗪和吡虫啉）残留量。结果表明：在0.1~10.0 mg/L范围内,5种农药的色谱峰面积与其浓度均呈良好的线性关系,相关系数均大于0.9994,在0.1、0.5、1 mg/L的添加水平下,5种农药在空白茶叶样品中的平均回收率均在85%~95%之间,相对标准偏差(RSD)在0.55%~2.5%之间。该方法符合农药残留分析实验要求,灵敏度高。     

欧盟禁“烟”的中国式思考

<正>新烟碱类杀虫剂作为当前农业生产中重要品种被世界各国广泛使用,近期欧盟委员会对吡虫啉、噻虫嗪及噻虫胺等3种新烟碱类农药采取限用措施,引起了世界各国的广泛关注。我国是农药生产大国,欧盟禁"烟"自然引起了业界的普遍担忧,很多企业担心噻虫嗪会重蹈氟虫腈的覆辙。吡虫啉、噻虫嗪及噻虫胺等3种新烟碱类农药之所以遭禁厄运,是因为产品的安全性问题。据越来越多的证据显示,这3种新烟碱类农药"对蜜蜂等授粉昆虫生存造成威胁,并导     

液相色谱-串联质谱法分析噻虫嗪在菜薹上的残留行为

为了明确噻虫嗪在菜薹上使用后的残留行为，在6个省市开展了噻虫嗪在菜薹上的最终残留试验，在其中2个省份开展了消解动态试验。样品采用固相萃取柱净化，高效液相色谱-串联质谱法(HPLC-MS/MS)测定，外标法定量。结果表明：添加水平在0.01～1.0 mg/kg下，噻虫嗪及其代谢物噻虫胺在菜薹中的添加回收率为89%～102%和93%～100%，相对标准偏差为5.8%～8.5%和4.0%～9.5%，定量限(LOQ)为0.01 mg/kg。消解动态试验结果表明，山东和安徽两地噻虫嗪在菜薹上的降解半衰期分别为1.8 d和1.2 d;6个省市的最终残留试验结果显示，用药量56.25～84.375g a.i./hm²，施药2～3次，药后10 d，收获的菜薹中噻虫嗪的残留量为2，最多施药2次，推荐安全间隔期为7 d。     

新烟碱类农药风险分析研讨会在北京召开

<正>本刊讯新烟碱类杀虫剂作为当前农业生产中重要品种被世界各国广泛使用,近期欧盟委员会对吡虫啉、噻虫嗪及噻虫胺等3种新烟碱类农药采取限用措施,引起了各方的广泛关注。为进一步加强我国新烟碱类农药安全管理,研讨此类农药的具体管理措施,7月1日,农业部农药检定所在北京召开了新烟碱类农药风险分析研讨会。来自全国农业技术推广服务中心、中国农科院、中国农业大学、     

QuEChERS-HPHPLC联用法检测蔬菜中有机磷农药多残留分析

建立了QuEchERS-HPLC联用法检测蔬菜中有机磷农药多残留的方法。改进了QuEchERS前处理方法,提高回收率及结果准确性,然后运用HPLC进行分析检测,根据有机磷农药的差异,得出其最小检出限在0.02μg/kg～55.75μg/kg之间,定量限0.1μg/kg～189.23μg/kg,18种有机磷农药要在定量限浓度和四倍定量限浓度2个加标水平的回收率均在70%～120%范围,相对标准偏差低于20%,试验表明本方法适用于蔬菜中有机磷农药的多残留检测分析。     

欧盟启动三种新烟碱类农药限用新规的相关情况解析

<正>欧盟宣布从2013年12月1日起对吡虫啉、噻虫嗪和噻虫胺农药实施限用政策,以降低或避免对蜜蜂的种群危害。新烟碱类农药是我国目前在蔬菜水果和粮食作物上使用最广泛的杀虫剂类别,也是我国农药出口创汇的主打品种,欧盟新烟碱类农药管理政策的变化,势必将对我国农药生产、使用以及农产品贸易带来较大影响……     

小麦和土壤中辛硫磷残留量的液相色谱分析方法研究

研究了小麦茎叶、籽粒和土壤中辛硫磷残留物的液相色谱分析方法。该方法仪器最小检出量为0.5 ng;当小麦籽粒和土壤中辛硫磷的添加浓度为0.02,0.2,2 mg/kg时,样品的平均回收率为89.8%~98.9%,变异系数为0.8%~5.7%,最低检测浓度为0.02 mg/kg;当茎叶中辛硫磷的添加浓度为0.04,0.4,2 mg/kg时,样品的平均回收率为89.7%~95.8%,变异系数为0.5%~5.9%,最低检测浓度为0.04 mg/kg。方法的灵敏度、精密度和检测限都符合农药残留分析的要求。     

2种不同种衣剂对玉米‘黑糯100’生长状况和抗氧化防御系统的影响

本研究通过田间试验,选择噻虫嗪和噻虫嗪-苯醚甲环唑混剂2种内吸性农药作为玉米种衣剂,探究了种衣剂对玉米乳熟期果穗鲜重,不同生长时期各部位鲜重的影响,以及对玉米植株抗氧化防御系统的影响。结果表明：以推荐使用剂量（6 mL/kg种子）,种衣剂对玉米植株各部位鲜重的影响主要在玉米苗期和拔节期,相比对照处理,噻虫嗪和噻虫嗪-苯醚甲环唑混剂处理明显降低玉米苗期和拔节期各部位鲜重,乳熟期时3个处理之间差异不显著;施用种衣剂能增加果穗鲜重,但增加效果不明显。种衣剂处理均促进植株叶绿素的合成,且噻虫嗪和苯醚甲环唑混施较单施噻虫嗪玉米叶绿素含量更高。单施噻虫嗪和噻虫嗪与苯醚甲环唑混合施用均会引起玉米叶片中抗氧化酶SOD、CAT和POD活性的提高,使叶片GSH和MDA含量降低,说明在本试验施用的种衣剂剂量胁迫环境下,玉米叶片抗氧化防御系统可作出应答,调节细胞的代谢过程,使玉米植株正常生长。     

加拿大魁北克省新农药法规限用五种农药

正今年2月加拿大魁北克省实施了关于管理使用和销售几个最具争议农药的新法规,以保护环境和健康。新法规将限用五种新农药:莠去津(除草剂)、毒死蜱(杀虫剂)和噻虫胺、吡虫啉和噻虫嗪三种新烟碱类(杀虫剂)。此外新烟碱类种子处理剂也受到了法规约束。根据几项科学评估,政府认为三种新烟碱     

Avoidance of leaf rust fungi in wild relatives of cultivated cereals

Summary Avoidance of rust fungi that was based on poor appressorium induction was previously found in Hordeum chilense. In the present study 95 accessions of Triticeae were screened for avoidance of Puccinia hordei. The percentage of appressorium formation per germinated spore ranged from 6 to 90%. On none of the 41 accessions of Aegilops, Agropyron, Elymus, Secale, Thinopyrum or Triticum studied was the rate of appressorium formation lower than 25%. Lower rates of appressorium formation were, however, found on accessions of wild barley species Hordeum brachyantherum, H. marinum, H. parodii and H. secalinum. Its implications in cereal breeding are discussed.     

A note on the origin of Kalanchoë x vadensis Boom & Zeilinga (Crassulaceae)

Summary K x vadensis is a hybrid of K. blossfeldiana and K. marmorata obtained after doubling the number of chromosomes.     

Relation between wheat-rye crossability and seed set of common wheat after pollination with other species in the Hordeae

Summary Cultivars of common wheat (Triticum aestivum L. em. Thell.) of high wheat-rye (Secale cereale L.) crossability set more seed with pollen of other related species than did wheats of low wheat-rye crossability. This was found to be true for pollen parents from the genera Triticum, Aegilops, Secale, Agropyron and Elymus.     

Breeding apomictic bahiagrass (Paspalum notatum Flügge) with improved turf traits

The development of a turf‐type bahiagrass could have a remarkable impact on the billion‐dollar turf industry in the south‐eastern United States. The goals of this study were to (i) select bahiagrass genotypes with improved turf attributes and (ii) determine the reproductive mode and seed fertility of selected genotypes. The population included mutants, wild types, hybrids and standard cultivars evaluated at two locations for two years. Morphological variation was observed and clonal repeatability (H²) ranged from 0.27 to 0.90. Flowering was extremely reduced in some mutants, which also exhibited dark green colour, finer texture and reduced canopy height. Cytoembryological observations revealed that diploids reproduced sexually and tetraploids by obligate or facultative apomixis. Genotypes with superior seed fertility were identified, while others were comparable to the standard cultivars. While mutant plants exhibited great morphological variation, the random mutations did not affect their reproductive mode, validating the use of mutagenesis in apomictic species. The high H² indicated that selection for improved turf attributes could be successfully performed with the advantage of clonal seed propagation.     

Inheritance of fruit colour in a wild Russian red raspberry seedling

Summary A new gene, i, from a self-incompatible wild Russian Rubus idaeus seedling is described. The gene i interacts with the fruit colour gene T, Tii plants having apricot instead of red fruits, and spines, leaves and stems pigmented to varying degrees. A deficit of apricot-fruited seedlings in progenies segregating for i could be explained by linkage between i and the self-incompatibility S locus with a crossover value of approximately 26.7%.Segregations for spine colour in crosses and backcrosses of the Russian seedling with two green-spined (ttII) raspberries selected for their yellow fruit colour, showed that both the latter carried the spine colour intensifier gene P. This suggests that earlier authors were incorrect in attributing the apricot fruit colour developed by some tt plants to a pleiotropic effect of P.     

Flag Leaf Senescence, as Evaluated by Numerical Image Analysis, and its Relationship with Yield under Drought in Durum Wheat

Senescence was evaluated at different stages of the grain‐filling period in eight durum wheat varieties using numerical image analysis (NIA). The varieties were grown under early, severe drought conditions on the high plains of Sétif in Algeria. After flowering, three different irrigation treatments were applied. Treatment effect was small, while a genotypic effect was noted for most of the senescence parameters. Senescence correlated to biomass, while the maximal rate of senescence, V_smax, correlated to thousand‐kernel weight. The potential of the method of numerical image analysis for monitoring flag leaf senescence, detecting genotypic variability and selecting genotypes with delayed senescence is discussed.     

Mechanisms and diversity of resistance to sorghum shoot fly,Atherigona soccata

Sorghum shoot fly, Atherigona soccata, is one of the important pests of postrainy season sorghums. Of the 90 sorghum genotypes evaluated for resistance to this pest, RHRB 12, ICSV 713, 25026, 93046 and 25027, IS 33844‐5, Giddi Maldandi and RVRT 3 exhibited resistance in postrainy season, while ICSB 463, Phule Anuradha, RHRB 19, Parbhani Moti, ICSV 705, PS 35805, IS 5480, 5622, 17726, 18368 and 34722, RVRT 1, ICSR 93031 and Dagidi Solapur showed resistance in rainy season, suggesting season‐specific expression of resistance to A. soccata. ICSB 461, ICSB 463, Phule Yasodha, M 35‐1, ICSV 700, 711, 25010, 25019 and 93089, IS 18662, Phule Vasudha, IS 18551 and 33844‐5 and Barsizoot had fewer deadhearts than plants with eggs across seasons, suggesting antibiosis as one of the resistance mechanism. Five genotypes exhibited resistance with high grain yield across seasons. Correlation, path and stepwise regression analyses indicated that leaf glossiness, seedling vigour, trichome density, oviposition and leaf sheath pigmentation were associated with the expression of resistance/susceptibility to shoot fly, and these can be used as marker traits to select and develop shoot fly‐resistant sorghums.     

Cowpea (Vigna unguiculata): Genetics,genomics and breeding

Cowpea, Vigna unguiculata (L.), is an important grain legume grown in the tropics where it constitutes a valuable source of protein in the diets of millions of people. Some abiotic and biotic stresses adversely affect its productivity. A review of the genetics, genomics and breeding of cowpea is presented in this article. Cowpea breeding programmes have studied intensively qualitative and quantitative genetics of the crop to better enhance its improvement. A number of initiatives including Tropical Legumes projects have contributed to the development of cowpea genomic resources. Recent progress in the development of consensus genetic map containing 37,372 SNPs mapped to 3,280 bins will strengthen cowpea trait discovery pipeline. Several informative markers associated with quantitative trait loci (QTL) related to desirable attributes of cowpea were generated. Cowpea genetic improvement activities aim at the development of drought tolerant, phosphorus use efficient, bacterial blight and virus resistant lines through exploiting available genetic resources as well as deployment of modern breeding tools that will enhance genetic gain when grown by sub‐Saharan Africa farmers.     

Screening for resistance to take-all in wheat,triticale and wheat-triticale hybrid lines

Summary Fifteen triticale and wheat-triticale hybrid lines were evaluated for resistance to the take-all fungus Gaeumannomyces graminis var. tritici and compared with five wheat and two rye lines in inoculated field and pot trials. The triticale and wheat-triticale hybrid lines varied in rye chromosome number and degree of resistance expressed. One line, Venus with seven pairs of rye chromosomes consistently showed levels of resistance intermediate between wheat and rye. A trend was observed where increasing rye chromosome content led to greater resistance but exceptions showed that variation within triticales could not be ascribed to rye chromosome content alone.     

Reaction of tritordeum to Fusarium culmorum and Septoria nodorum

Summary Hordeum chilense is a wild barley extensively used in wide crosses in the Triticeae. It could be a valuable source of resistance to Fusarium culmorum and Septoria nodorum. Some H. chilense x Triticum spp. amphiploids, named tritordeums, were more resistant than the parental wheat line to these diseases, others were not. Average contents of ergosterol and deoxynivalenol (DON) suggested that resistance to colonization by Fusarium was the highest for Hordeum chilense, followed by tritordeum and wheat in decreasing order. In particular, the H. chilense genotypes H7 and H17 enhanced the wheat resistance to F. culmorum in its tritordeum offsprings. Resistance to S. nodorum in tritordeum was not associated with tall plant height. There is sufficient genetic variation for resistance to F. culmorum and S. nodorum among tritordeum to allow the breeding of lines combining short straw and resistance to both diseases.