The toxicity of phosphine,methyl bromide, 1,1,1-trichloroethane and carbon dioxide alone and as mixtures to the pupae of red flour beetle,Tribolium castaneum herbst     

Somiahnadar Rajendran 《Pest management science》1990,29(1):75-83

The toxicity of phosphine, methyl bromide, 1,1,1-trichloroethane (methyl chloroform) and carbon dioxide and mixtures of phosphine + methyl bromide, methyl bromide + methyl chloroform, phosphine + carbon dioxide, and methyl bromide + carbon dioxide to one- to two-day-old pupae of Tribolium castaneum Herbst was studied. Joint action ratios estimated at LD₅₀ and LD₉₀ for a 24-h exposure indicated no enhancement of toxicity for mixtures of phosphine and methyl bromide, or methyl chloroform and methyl bromide on the pupae. Carbon dioxide up to 40% in air enhanced the toxic action of phosphine as well as of methyl bromide. Higher levels of carbon dioxide, however, failed to improve the toxicity of phosphine or methyl bromide proportionately. Carbon dioxide used alone produced a maximum of 11% mortality of the pupae exposed to 10–70% levels for 24 h. The order of toxicity of the fumigants both at LD₅₀ and LD₉₀ was phosphine > methyl bromide > methyl chloroform.  相似文献   

The action of phosphine against the eggs of phosphine-resistant and -susceptible strains of Rhyzopertha dominica F     

Rajendran S  Nayak KR  Anjum SS 《Pest management science》2001,57(5):422-426

The effect of phosphine at exposure periods of 24, 48 and 120 h on hatching and mortality of 0- to 1-day-old eggs of susceptible (TN6) and resistant (FC10) strains of Rhyzopertha dominica of field origin was investigated. The fumigant affected hatching in both the strains. In a 48-h exposure at 27 (+/- 2) degrees C, the LD99 doses for the eggs of TN6 and FC10 were 0.56 and 3.25 mg litre-1, respectively. Significant reduction in hatching was observed in treated batches with progressive increase of phosphine dose in the first 2-3 days. On subsequent days the numbers hatching were often similar to those in controls, and sometimes exceeded control hatch, especially following a 5-day exposure. A critical change in the order of susceptibility of egg and adult stages of the two strains was noticed. In 48-h exposures, eggs of the susceptible strain were more tolerant than their adults, whilst the reverse was true in the resistant strain.  相似文献   

苇状羊茅盐胁迫下生理效应的研究   总被引：51，自引：0，他引：51  

董晓霞  赵树慧 《草业科学》1998,15(5):10-10

应用砂培试验对苇状羊茅盐胁迫下的生理效应进行了研究,通过对苇状羊茅盐胁迫下的相对鲜重,相对干重,根冠比,脯氨酸含量,叶绿素含量及根系活力进行测定,表明,低浓度的盐处理下,苇状羊茅生长未表现出受不利因素影响,但此时羊茅已对外界高渗溶液做出生理反应,叶片中脯氨酸含量成倍增加;随着盐胭控浓度的增大,羊茅相对鲜重,相对干重,根系活力均降低２,生长和生理上都表现出盐害效应同时叶片中脯氨酸和叶绿素含量增加,反  相似文献   

Standardisation of true cassava seed (TCS) programme with special emphasis on more homogeneous, CMD resistant progenies     

P. G. Rajendran  C. Mohan  J. Sreekumar 《Euphytica》2005,142(1-2):13-22

The propagation of cassava through true seeds (sexual seeds) rather than by clones is a promising option due to its manifold advantages such as enhancing the multiplication rate, keeping the dreaded cassava mosaic disease (CMD) under check, longer seed viability, ease of storage and transport. The high genetic heterogeneity and consequent variation among seedlings is the major stumbling block in sexual propagation. In the present study, a CMD resistant exotic accession MNga-1 and a promising cultivar Ambakadan with profuse fruit setting, seed output and male sterility were identified to be promising parents for the TCS programme. The rate of sexual propagation could be more than 20-fold over the traditional clonal propagation. Seed treatment with 1% KNO₃ or 300 ppm GA promoted uniform seed germination and seedling vigour and reduced the transplanting period from 45 days after planting (DAS) to 30 DAS. Removal of taproots of seedlings while transplanting enhanced tuber development. Tuber yield of first clones (C₁) was significantly superior to that of the seedlings. The dry matter content and starch output of seedlings and first clones were comparable to that of the commercial varieties. Similarly, the HCN and cooking quality of seedlings and first clones were at acceptable levels. In the open pollinated (OP) progenies of the Ambakadan the CMD infection increased drastically due to secondary spread of the pathogen. The hybrid progenies of Ambakadan and the CMD resistant line MNga-1 revealed higher percentage of CMD free seedlings and first clonal progenies in the evaluation trials conducted at CTCRI Thiruvananthapuram and ARS, Peddapuram during 2001–2002 and 2002–2003. Nearly homogeneous hybrid population resistant to CMD could be obtained by systematic roguing at seedling and first clonal stage.  相似文献   

Ceramide triggers budding of exosome vesicles into multivesicular endosomes   总被引：5，自引：0，他引：5  

Trajkovic K  Hsu C  Chiantia S  Rajendran L  Wenzel D  Wieland F  Schwille P  Brügger B  Simons M 《Science (New York, N.Y.)》2008,319(5867):1244-1247

Intraluminal vesicles of multivesicular endosomes are either sorted for cargo degradation into lysosomes or secreted as exosomes into the extracellular milieu. The mechanisms underlying the sorting of membrane into the different populations of intraluminal vesicles are unknown. Here, we find that cargo is segregated into distinct subdomains on the endosomal membrane and that the transfer of exosome-associated domains into the lumen of the endosome did not depend on the function of the ESCRT (endosomal sorting complex required for transport) machinery, but required the sphingolipid ceramide. Purified exosomes were enriched in ceramide, and the release of exosomes was reduced after the inhibition of neutral sphingomyelinases. These results establish a pathway in intraendosomal membrane transport and exosome formation.  相似文献   

Influence of phosphine on hatching of Cryptolestes ferrugineus (Coleoptera: Cucujidae), Lasioderma serricorne (Coleoptera: Anobiidae) and Oryzaephilus surinamensis (Coleoptera: Silvanidae)     

Rajendran S  Parveen H  Begum K  Chethana R 《Pest management science》2004,60(11):1114-1118

The hatching and mortality response of 0- to 48-h-old eggs of field strains of the stored-product insects Cryptolestes ferrugineus (Stephens), Lasioderma serricorne (F) and Oryzaephilus surinamensis (L) following phosphine fumigation for 24, 48 or 120 h at 27 (+/- 2) degrees C was investigated. Hatching was delayed and reduced in the first few days in a phosphine-resistant strain of C ferrugineus that was treated with 2.0-7.0 mg litre(-1) doses for 48 h (5-80% mortality) and with 1.0-2.0 mg litre(-1) for 120 h (44-84% mortality). In both the exposures there were significant increases in hatching on later days when compared with the corresponding controls. Developmental delay was, however, not evident in susceptible strains of C ferrugineus, L serricorne and O surinamensis that were exposed to phosphine for 24 h.  相似文献   

UPLC-MS/MS法同时测定牛奶中替米考星、地塞米松、氟苯尼考和氯霉素残留     

仲伶俐  郭灵安  毛建霏  李曦  胡莉  雷欣宇  欧阳华学  李华仙 《中国畜牧兽医》2018,45(9):2645-2652

试验旨在建立一种同时测定牛奶中替米考星（tilmicosin）、地塞米松（dexamethasone）、氟苯尼考（florfenicol）和氯霉素（chloramphenicol）的超高效液相色谱-串联质谱（ultra performance liquid chromatography-tandem mass spectrometry,UPLC-MS/MS）法。牛奶样品经乙腈提取后,将提取液通过Oasis PRiME HLB固相萃取小柱净化,净化后的样液经氮吹浓缩后,用样品稀释液溶解并用正己烷进一步除去脂肪获得待分析样品,进行UPLC-MS/MS分析。采用CAPCELL PAK C18 MGⅢ-H色谱柱（2 mm×100 mm,3 μm）进行液相色谱分离,以甲醇（A）-含0.01%甲酸的0.1 mmol/L甲酸铵溶液（B）为流动相进行梯度洗脱：0~1.0 min,90%至60% B;1.0~3.0 min,60%至30% B;3.0~4.4 min,30%至20% B;4.4~4.5 min,20%~90% B;4.5~6.0 min,90% B。在多反应监测（multiple reaction monitoring,MRM）模式下进行质谱测定,以基质匹配标准溶液外标法定量。结果显示,替米考星、地塞米松、氟苯尼考和氯霉素在1.0~100.0 μg/L范围内均具有良好的线性关系（r>0.999）。方法的最低检测限（limits of detection,LODs）为0.1~0.2 μg/kg,定量限（limits of quantity,LOQs）为0.2~0.5 μg/kg,当4种化合物在牛奶中的添加水平为0.5、5.0和25.0 μg/kg时,回收率为78.6%~94.7%,相对标准偏差（relative standard deviations,RSDs）为2.4%~10.1%。本试验建立的UPLC-MS/MS方法简便、灵敏、准确,适用于牛奶中替米考星、地塞米松、氟苯尼考和氯霉素的同时测定。  相似文献   

Evaluation of interferon gamma (IFN-γ) of <Emphasis Type="Italic">Labeo rohita</Emphasis> as an immunomodulator: in vitro expression model     

Megha Kadam Bedekar  Praveena Soman  Sajal Kole  Deepika Anand  Gayatri Tripathi  M. Makesh  K. V. Rajendran 《Aquaculture International》2018,26(6):1401-1413

Interferon gamma (IFN-γ) or type II interferon is a cytokine that is critical for innate and adaptive immunity against viral and some bacterial and protozoal infections. The importance of IFN-γ in the immune system lies in its ability to inhibit viral replication directly and most importantly from its immunomodulatory effects. Previously, we successfully co-administered IFN-γ along with GAPDH gene of Edwardsiella tarda as bicistronic DNA vaccine in Labeo rohita. In order to ascertain the individual role of IFN-γ, the present study involves cloning and expression of 552-bp IFN-γ open-reading frame (ORF) of L. rohita in striped snakehead (SSN-1) cell line using eukaryotic expression vector system (pQE-TriSystem) followed by transfection in peripheral blood lymphocytes (PBMCs) to evaluate its immunomodulatory ability in comparison to polyinosinic-polycytidylic acid (Poly I:C)-treated PBMCs. The 18.7-kDa protein, expressed in the pQE-IFNγ-transfected SSN-1 cells, reacted with anti-His antibody in Western blot confirming it to be recombinant IFN-γ, whereas the relative expression of IFN-γ, iNOS, Mx, and IL-1β genes in PBMCs was quantified at 24 h and 48 h post treatment by qPCR. The comparative kinetics of all four genes showed significantly (p?<?0.05) high upregulation pattern in both pQE-IFNγ-transfected cell group and Poly I:C-treated cell group demonstrating recombinant IFN-γ as an equally efficient inducer like Poly I:C. Thus, our in vitro experiment results highlight the immunomodulatory potential of recombinant IFN-γ as an analogue to synthetic Poly I:C which warranted future studies to further explore the potential of recombinant IFN-γ as an effective vaccine adjuvant against different microbial invasion.  相似文献   

Protein phosphatases 1 and 2A and the regulation of calcium uptake and pollen tube development in Picea wilsonii     

Kong L  Wang M  Wang Q  Wang X  Lin J 《Tree physiology》2006,26(8):1001-1012

To investigate the roles of protein phosphatases 1 and 2A in the development of pollen tubes of Picea wilsonii Mast., pollen grains were cultured in standard medium in the presence and absence of the protein phosphatase inhibitors okadaic acid and calyculin A. At nanomolar concentrations, these compounds blocked pollen tube growth, causing abnormal morphologies of the pollen tubes. Studies with Fluo-3 revealed that the inhibitors reduced the pollen-tube tip-to-base cytoplasmic calcium (Ca(2+)) gradient and arrested extracellular Ca(2+) uptake. The transmission electron microscope observations indicated that the fusion of paramural bodies with plasma membranes occurred frequently in the tip and sub-tip regions of control pollen tubes, but fusion rarely occurred in inhibitor-treated pollen tubes. Staining with aniline blue showed that callose accumulated in the tip regions of inhibitor-treated pollen tubes. Immunolabeling of pollen tubes revealed that acidic pectin epitopes recognized by the monoclonal antibody JIM5 were present in the tip region and on the flanks of the sub-tip in normal pollen tubes. In inhibitor-treated pollen tubes, these epitopes existed only in the extreme tip region and at higher concentrations than in control pollen tubes. The esterified pectin recognized by JIM7 was located preferentially at the extreme tip region in normal pollen tubes, but at basal sites in inhibitor-treated tubes. Fourier transform infrared (FTIR) analysis further confirmed the changes in acidic and esterified pectin distributions and their relative contents. These results suggest that protein phosphatase 1 or 2A, or both, are involved in the regulation of Ca(2+) uptake across the plasma membrane, in exocytotic activity and in the biosynthesis of cell wall components, all processes that occur in the tip region of pollen tubes and that control pollen tube development.  相似文献   

不同基因型小麦NDVI 值与产量的关系   总被引：4，自引：0，他引：4  

李升东  王法宏  司纪升  孔令安  冯波  张宾 《干旱地区农业研究》2008,26(6):47-50

在旱地保护性耕作条件下,以11个不同基因型小麦(Triticum aestivumL.)品种为材料,研究了植被归一化指数(NDVI,Normalized difference vegetation index)与产量构成和抗旱性的关系。结果表明,不同基因型小麦各生育期的归一化植被指数(NDVI)存在显著性差异;小麦抽穗期NDVI值与其干旱产量指数呈正相关,抽穗期NDVI值较高的小麦品种其干旱产量指数也较高;本试验条件下,石麦15、石家庄8号和烟Blu6439三个小麦品种的干旱产量指数较高。  相似文献