砜嘧磺隆25%可湿性粉剂在马铃薯中的残留动态

为了制定砜嘧磺隆在马铃薯生产中的安全使用标准,采用田间试验的方法,研究砜嘧磺隆在马铃薯中的残留动态,应用液相色谱法测定砜嘧磺隆在马铃薯中的残留量。试验结果表明:砜嘧磺隆在马铃薯植株和土壤中降解符合一级化学反应动力学方程C=C0e-kt,砜嘧磺隆在土壤中半衰期为(0.02～3.10 d),在植株中的半衰期为(0.93～2.90 d)。该药属易分解农药(T1/2<30 d)。在马铃薯4叶期时喷药1次,按推荐剂量90 g/hm2及1.5倍剂量135 g/hm2施用25%可湿性粉剂砜嘧磺隆。在收获期马铃薯植株和块茎均未检测出,在马铃薯上的砜嘧磺隆安全使用量推荐为90 g/hm2,建议马铃薯上砜嘧磺隆最大残留限量值MRL暂定为0.1 mg/kg。     

土壤中氯嘧磺隆对马铃薯和甜菜生育的影响

为了明确土壤中氯嘧磺隆对马铃薯和甜菜生育的影响,分别在苗期和生育盛期向盆栽土壤中灌施不同浓度的氯嘧磺隆溶液,调查作物生育产量。结果表明:供试的马铃薯和甜菜苗期耐药能力弱,生育盛期耐药能力增强;马铃薯耐药能力比甜菜强。马铃薯临界浓度苗期为0.017 a.i.mg/kg土,生育盛期约为0.071 a.i.mg/kg土;甜菜苗期至少小于0.0002 a.i.mg/kg土,生育盛期约为0.011 a.i.mg/kg土。马铃薯苗期抑制产量EC50值约为0.065 a.i.mg/kg土,生育盛期约为0.200 a.i.mg/kg土;甜菜苗期因植株死亡未得到数据,生育盛期约为0.014 a.i.mg/kg土。     

高效降解真菌对大豆田除草剂氯嘧磺隆的降解特性研究

经过摇瓶富集培养,从氯嘧磺隆驯化的土壤中分离出一株大豆田除草剂氯嘧磺隆高效降解真菌,实验室暂时命名为F8.F8的纯培养结果表明:在28℃,接种量5%(体积比)的麦芽汁液体培养基中,120r·min-1振摇96h,其对10mg·L-1氯嘧磺隆的降解率达93.85%.当F8加到土壤中时,可明显促进氯嘧磺隆的降解,在28℃,土壤含水量20%,接种量20ml·kg-1时可使30ug·kg-1氯嘧磺隆的降解半衰期由自然条件下的46.52d缩短为15.03d.     

豆田残留除草剂氯嘧磺隆在土壤空间分布的研究

分别在有除草剂污染的豆田土壤和无除草剂污染的正茬土壤分层采集土壤样本,在盆栽条件下种植甜菜,鉴定农药残留。结果表明:大豆田土壤中残留的氯嘧磺隆主要分布在0~20 cm土层中,残留量随着土层深度的增加逐渐减少。其中0~10 cm土层植株生长到4叶期全部死亡,表明该层残留农药最多;10~20 cm土层对甜菜生长产生严重抑制,表现为株高降低37%,鲜重降低31.7%;20 cm以下土层的甜菜正常生长,该层氯嘧磺隆的残留量对下茬作物无明显影响。通过对特定指示作物甜菜苗期生长发育的研究揭示了豆田除草剂氯嘧磺隆在不同深度的分布特点,为进一步研究消除残留除草剂药害提供科学依据。     

新型除草剂解毒剂减轻氯嘧磺隆残留对玉米的药害作用及机理

以垦玉6号玉米为试验材料,采用土培法研究新型除草剂解毒剂N-二氯乙酰基-2-甲基-1-氧杂-4-氮杂-螺[4.4]壬烷减轻除草剂氯嘧磺隆残留对玉米产生的药害,初步探讨其机理。研究结果表明,随土壤中氯嘧磺隆残留浓度增加,玉米生长受到抑制。采用不同浓度解毒剂浸种处理后,均可在一定程度上减轻氯嘧磺隆残留对玉米产生的药害。当土壤中氯嘧磺隆的残留浓度为2μg/kg,解毒剂的浸种浓度为5 mg/kg时解毒效果最好,玉米株高和主根长的恢复率可达对照的109.71%和90.99%,幼苗中的谷胱甘肽(GSH)含量和乙酰乳酸合成酶活性(ALS)分别达到对照的106.8%和116.7%。     

高效降解氯嘧磺隆菌株的分离筛选

以氯嘧磺隆为唯一碳源,从多年施用氯嘧磺隆的土壤中经富集和分离纯化获得了8株氯嘧磺隆降解菌.通过对其菌体和菌落形态的观察,确定其中有5株细菌,2株放线菌和1株真菌.采用玉米主根生长抑制率的生物测定法,对8株菌的氯嘧磺隆降解率进行测定,最终筛选出l株氯嘧磺隆高效降解放线菌B-4,其氯嘧磺隆降解率可达97.2％.     

不同长残留除草剂对大豆根际土壤脲酶活性的影响

研究了咪唑乙烟酸、氯嘧磺隆和异(口恶)草酮3种大豆田长残留除草剂对土壤脲酶活性的影响.结果表明,3种长残留除草剂对大豆根际土壤脲酶活性的影响程度不同.咪唑乙烟酸、氯嘧磺隆、异(口恶)草酮施用后最初对脲酶活性均具有显著的抑制作用.但随着除草剂施用后时间的延长,咪唑乙烟酸处理土壤脲酶活性开始增强并与对照差异达到极显著水平;氯嘧磺隆处理土壤脲酶活性则逐渐恢复至正常状态;异(口恶)草酮处理土壤脲酶活性开始恢复时间最早,并且脲酶活性显著高于对照的持续时间最长.     

乐果在香草兰和土壤中的残留动态

田间试验条件下,以推荐浓度N(625 mg/L.),2N(1 250 mg/L.),4N(2 500 mg/L)三个施药浓度分别喷施处理植株和土壤.用气相色谱法分析乐果在香草兰植株和土壤中的残留动态.结果表明:乐果在土壤中降解很快.半衰期为0.8～0.9d;植株喷施乐果时,香草兰果、茎、叶中的半衰期分别为6.1～6.4d,2.5～4d,3～4.2d;土表喷药后,乐果在植株各组织中的残留量远低于植株直接喷药的残留量,其最大残留量为0.094 1 mg/kg.不同施药方式,乐果在香草兰果、茎、叶中的残留动态曲线不同.植株喷药时,乐果在香草兰果、茎、叶中的残留量随着时间的延长逐渐降低;而土表喷药时.则呈先升高后降低的趋势,且在喷药后第1 d达到最大.比较香草兰各组织的最大残留量.植株喷药后表现为叶≥果>茎;土表喷药后则表现为果>叶>茎.但就消减动态而言,喷施同样浓度的乐果后,果荚中消减最慢,最后的残留量最大,说明果荚容易吸收积累乐果.     

苯醚甲环唑和嘧菌酯在水稻中的残留消解动态及残留分析

本文建立了气质联用仪测定稻田环境中苯醚甲环唑和嘧菌酯的残留分析方法,对苯醚甲环唑和嘧菌酯在水稻、土壤和田水中的消解动态和残留规律进行了研究。苯醚甲环唑和嘧菌酯在糙米、稻壳、植株、土壤和田水中的最低检测浓度均为0.20 mg/kg,最小检出量为0.2 ng,在不同样品中的平均加标回收率为80.8%~109.5%,相对标准偏差在1.7%~19.7%之间。田间试验结果表明,苯醚甲环唑和嘧菌酯在水稻植株和田水中的残留消解动态规律均符合一级动力学反应模型,苯醚甲环唑在水稻植株和田水中的残留消解半衰期分别为6.3~11.6 d和1.4~11.6 d;嘧菌酯在水稻植株和田水中的残留消解半衰期分别为3.6~8.7 d和2.9~23.1 d。以推荐剂量600 g/hm2和1.5倍推荐剂量900 g/hm2,最多施药3次,距最后一次施药15 d时,苯醚甲环唑和嘧菌酯在糙米中的最高残留量分别为0.461 mg/kg和0.634 mg/kg,低于我国国家标准《食品中农药最大残留限量》(GB2763-2014)中规定的糙米中苯醚甲环唑最大残留限量0.5 mg/kg和欧盟、美国规定的糙米中嘧菌酯最大残留限量5.0 mg/kg。     

5种除草剂对油菜ALS酶活性的影响及杀雄作用评价

在油菜杂种优势利用中,为筛选新型化学杀雄剂,有效诱导雄性不育,以甘蓝型油菜自交系740C和Q8C为材料,使用5种除草剂(苯磺隆、氯吡嘧磺隆、环氧嘧磺隆、双草醚和阔草清),各4个稀释浓度(1/200、1/100、3/200、1/50)对现蕾期的植株进行喷施,在处理后1至4d分别采取油菜叶片和花蕾,测定乙酰乳酸合成酶(acetolactate synthase,ALS)酶活性,并在后期进行花粉活力的测定和育性分析。结果表明:双草醚、阔草清能够抑制ALS酶的活性但不具有化学杀雄作用。同一药剂不同浓度处理的油菜体内ALS酶活性表现为随药剂浓度升高而降低的趋势。740C比Q8C对5种除草剂更敏感,ALS酶活性抑制程度更明显。老叶、幼叶、花蕾对化学杀雄剂的敏感程度依次增加,其ALS酶活性逐步降低。筛选出氯吡嘧磺隆和环氧嘧磺隆,可以作为候选化学杀雄剂,适合浓度分别是1.3~2.6mg/L和1.5~3.0mg/L。     

Pharmacokinetics of Marine-Derived Drugs

Marine organisms represent an excellent source of innovative compounds that have the potential for the development of new drugs. The pharmacokinetics of marine drugs has attracted increasing interest in recent decades due to its effective and potential contribution to the selection of rational dosage recommendations and the optimal use of the therapeutic arsenal. In general, pharmacokinetics studies how drugs change after administration via the processes of absorption, distribution, metabolism, and excretion (ADME). This review provides a summary of the pharmacokinetics studies of marine-derived active compounds, with a particular focus on their ADME. The pharmacokinetics of compounds derived from algae, crustaceans, sea cucumber, fungus, sea urchins, sponges, mollusks, tunicate, and bryozoan is discussed, and the pharmacokinetics data in human experiments are analyzed. In-depth characterization using pharmacokinetics is useful for obtaining information for understanding the molecular basis of pharmacological activity, for correct doses and treatment schemes selection, and for more effective drug application. Thus, an increase in pharmacokinetic research on marine-derived compounds is expected in the near future.     

La pourriture fongique des tubercules de pomme de terre en atmosphère contrôlée

Résumé Fusarium culmorum et, dans une moindre mesure,F. avenaceum, F. sambucinum, Colletotrichum coccodes etCylindrocarpon sp. ont été isolés de tubercules entreposés en atmosphère contr?lée (AC) et atteints de pourriture grave. Des expériences d'inoculation de tubercules avec 10 espèces ou variétés fongiques et conservation en AC à 8 et 10°C ont montré que: 1) les champignons non pathogènes en atmosphère normale (ex.:Cylindrocarpon sp.) le devenaient en AC, 2) ceux qui étaient faiblement pathogènes en atmosphère normale étaient nettement plus virulents en AC (ex.:F. culmorum), 3) les espèces ou variétés virulentes en conditions d'air normales (Fusarium sulphureum etPhoma exigua var.foveata) ne provoquaient pas de pourriture plus grave en AC et leur activité pouvait même être légérement freinée.

---

Summary The extensive rotting of tubers which occurred during storage trials in controlled atmospheres has led to a mycological and pathological study of the rots. The most frequently isolated species wasFusarium culmorum althoughF. avenaceum, F. Sambucinum, Coletotrichum coccodes and aCylindrocarpon sp. were also present. Tubers of cvs Bintje and Ulla were inoculated with 19 isolates of 10 fungal species or varieties associated with rotting of stored tubers (Table 1). The tubers were incubated at 8 or 10°C in normal or controlled (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂) atmospheres and the extent of rotting was determined a month later (Tables 2 and 3 and Fig. 2). Species which were weakly virulent in a normal atmosphere (variousFusarium spp. andPhoma exigua var.exigua) were clearly more aggressive in the controlled atmosphere and this was especially evident in the case ofF. culmorum. Species ot pathogenic in a normal atmosphere under experimental conditions (Colletotrichum coccodes, Cylindrocarpon sp.,Phoma eupyrena) caused rotting in the controlled atmosphere. The two species which were virulent in a normal atmosphere (F. sulphureum andP. exigua var.foveata) were also virulent in the controlled atmosphere and in some cases the extent of rotting was even less. As a general rule, rotting caused by weakly virulent fungi was greater in both cultivars in the controlled than in a normal atmosphere.

---

Zusammenfassung Eine starke F?ulnis von in Kontrotrollierter Atmosph?re gelagerten Kartoffelknollen veranlasste eine mykologische und pathologische Untersuchung. Der am h?ufigsten isolierte Pilz warFusarium culmorum. F. avenaceum, F. sambucinum, Colletotrichum coccodes undCylindrocarpon sp. wurden ebenfalls bestimmt. Neunzehn St?mme von 10 Pilzsorten oder-Arten welche bei Lagerf?ulnis vorkommen (Tab. 1) wurden auf Knollen der Sorten Bintje und Ulla inokuliert. Die Lagerung wurde bei 8 oder 10°C under Normalbedingungen oder kontrollierter Atmosph?re durchgeführt (2% O₂:1% CO₂, 2% O₂:6% CO₂, 2% O₂:12% CO₂, 6% O₂:6% CO₂). Der F?ulnisgrad (Abb. 1) wurde nach einem Monat bonitiert. Die Ergebnisse sind in den Tabellen 2 und 3 dargestellt und in der Abb. 2 illustriert. Unter in Normalbedingungen nur schwach virulente Arten (verschiedeneFusarien undPhoma exigua var. exigua) waren deutlich aktiver in kontrollierter Atmosph?re. Dies was besonders der Fall fürF. culmorum. Pilze, die im Versuch unter Normalbedingungen nicht pathogen waren (Colletotrichum coccodes, Cylindrocarpon sp., Phoma eupyrena), haben unter kontrollierter Atmosph?re Sch?den verursacht. Hingegen werden die beiden unter Normalbedingungen sehr pathogenen Arten (F. sulphureum undP., exigua var.foveata), durch kontrollierte Atmosph?re wenig beeinflusst. Es wurde sogar in einigen F?llen eine gewisse Verringerung des F?ulnisbefalls beobachtet. Ganz allgemein haben die getesteten kontrollierten Bedingungen die Entwicklung der Pilzf?ulnis an beiden Kartoffelsorten gef?rdert, speziell durch Pilzarten, welche unter Normal-bedingungen wenig Sch?den verursachen.

     

Marine Pharmacology in 2016–2017: Marine Compounds with Antibacterial,Antidiabetic, Antifungal,Anti-Inflammatory,Antiprotozoal, Antituberculosis and Antiviral Activities; Affecting the Immune and Nervous Systems,and Other Miscellaneous Mechanisms of Action

The review of the 2016–2017 marine pharmacology literature was prepared in a manner similar as the 10 prior reviews of this series. Preclinical marine pharmacology research during 2016–2017 assessed 313 marine compounds with novel pharmacology reported by a growing number of investigators from 54 countries. The peer-reviewed literature reported antibacterial, antifungal, antiprotozoal, antituberculosis, and antiviral activities for 123 marine natural products, 111 marine compounds with antidiabetic and anti-inflammatory activities as well as affecting the immune and nervous system, while in contrast 79 marine compounds displayed miscellaneous mechanisms of action which upon further investigation may contribute to several pharmacological classes. Therefore, in 2016–2017, the preclinical marine natural product pharmacology pipeline generated both novel pharmacology as well as potentially new lead compounds for the growing clinical marine pharmaceutical pipeline, and thus sustained with its contributions the global research for novel and effective therapeutic strategies for multiple disease categories.     

Effects of Micronutrient Deficiencies on Human Health: Its Status in South Asia

SUMMARY

Vitamin A, iodine, and iron deficiencies affect large numbers of people worldwide. A deficiency of one or more of these micronutrients adversely affects the physical and mental abilities of humans. South Asia contains a high percentage of these individuals, not just because of its large population, but also the prevalence of deficiency is higher there than in many other parts of the world. The reasons for the high rates of deficiency in South Asia are many, but they include inadequate availability of micronutrient-rich foods, sub-optimal dietary habits, and high rates of infection. Across the region, national plans vary from (a) increasing availability of appropriate foods, (b) introducing new dietary behaviors, (c) improving health status, and (d) directly addressing deficiency through intervention programs. The extent to which each of the countries is making progress toward the goals of these plans can help in understanding the priorities for future efforts to address micronutrient malnutrition. This article discusses the adverse effects of micronutrient deficiencies in humans with special reference to South Asia.     

Irrigation but not N fertilization enhances seedhead density in plains rough fescue ( F estuca hallii)

Plains rough fescue ( F estuca hallii) is an important forage grass species in western Canada. Seed for use in pastures and ecological restoration is in high demand but supply is limited because F. hallii is an erratic seed producer. Seed producers require an understanding of the factors that influence flowering and seed set in this species. The aim of this study was to assess the effect of irrigation and nitrogen fertilization on the flowering and growth of F. hallii in a native rough fescue prairie in Alberta, Canada. Irrigation had a strong positive effect on seedhead density, whereas fertilization had limited effects on growth and reproduction of F. hallii. These results demonstrate that under field conditions, available moisture is likely to be a key factor driving flowering and seed production in F. hallii.     

Management of Soil Micronutrient Deficiencies in the Rice-Wheat Cropping System

Summary

Within the last three decades, the rice-wheat cropping system has triggered, and with time, aggravated soil micronutrient deficiencies in the Indo-Gangetic Plains (IGP). This has largely been due to the shift from an earlier rice and wheat monoculture with low yielding, long duration indigenous varieties, to an intensive rice-wheat rotation cropping system with short duration modern high yielding varieties on the same piece of land. The problems related to micronutrient deficiency in the IGP are more due to the size of its available pools in the soil rather than its total contents and are greatly influenced by crop management, or rather its mismanagement. Deficiency of zinc is widespread in the IGP, but with the extensive use of zinc sulfate, zinc deficiency has reduced in some areas of the region. Meanwhile, the deficiency of Fe, Mn and B has increased in the IGP. Deficiency of Cu and Mo is location specific and can limit rice and wheat yields. The adoption and spread of the rice-wheat system in permeable coarse textured soils, particularly in the western IGP, not only caused iron deficiency in rice but also resulted in the emergence of manganese deficiency in wheat. In highly calcareous and acidic soils, boron is the next limiting micronutrient in crop production after zinc. Bumper rice and wheat harvests in the past decade, the declining use of organic manures in the region and except for the widespread use of zinc sulfate, a general lack of awareness amongst farmers on micronutrient deficiency problems has contributed to micronutrients limiting rice and wheat yields in the IGP. Approaches to alleviating micronutrient deficiencies include matching the crop removals of the micronutrients with its replenishments through their respective external carriers, supplementation through organic sources and mobilization/utilization through cultivation of micronutrient efficient crop cultivars. Identification of efficient micronutrient carriers and finding the optimum rate, mode and time of its application is important in ameliorating the micronutrient deficiencies. This article reviews the extent of micronutrient deficiency and discusses various management options available to reduce micronutrient deficiency induced crop yield reduction for rice and wheat in the Indo-Gangetic Plains.     

Marine Drugs Regulating Apoptosis Induced by Tumor Necrosis Factor-Related Apoptosis-Inducing Ligand (TRAIL)

Marine biomass diversity is a tremendous source of potential anticancer compounds. Several natural marine products have been described to restore tumor cell sensitivity to TNF-related apoptosis inducing ligand (TRAIL)-induced cell death. TRAIL is involved during tumor immune surveillance. Its selectivity for cancer cells has attracted much attention in oncology. This review aims at discussing the main mechanisms by which TRAIL signaling is regulated and presenting how marine bioactive compounds have been found, so far, to overcome TRAIL resistance in tumor cells.     

Biochemical and morphological characterization of potato clones differing in their resistance to late blight

Summary Morphological and biochemical parameters that could be involved in resistance to late blight were studied in non-infected and in infected potato hybrids resulting from a cross betweenSolanum phureja, resistant toPhytophthora infestans, and a susceptibleSolanum tuberosum. Some morphological differences between resistant and susceptible hybrids, indicating a positive correlation between stem diameter and phloem thickness in the stem and resistance toP. infestans, were observed. The lignin content in the leaves of the resistant hybrid rose upon infection byP. infestans. In the leaves of the susceptible hybrid, a diminution of the lignin content could be observed upon infection byP. infestans. In the same context, peroxidasic activity raised upon infection byP. infestans in both resistant and susceptible hybrids. Further characterization of the hybrid clones based on the polymorphism of peroxidases was attempted using isoelectric focusing.     

Applied Biotechnology to Combat Late Blight in Potato Caused by <Emphasis Type="Italic">Phytophthora Infestans</Emphasis>

Potato is an important crop, grown worldwide. It suffers from many pests and diseases among which late blight, caused by the oomycete Phytophthora infestans, is the worst. The disease is still causing major damage in many potato production areas and control is only possible by applying fungicides frequently. The knowledge on the molecular biology and genetics of the interaction between the plant and the oomycete is developing rapidly. These are relevant fields of study, currently dominated by the discovery of many resistance genes and numerous effector proteins and the analysis of their specific mode of action. These studies may yield essential information needed for the development of durable resistance. The long-term and worldwide effort to breed for resistance so far has had little effect. A novel breeding approach may change this. It is based on cisgenic modification (CM) consisting of marker-free pyramiding of several resistance genes and their spatial and temporal deployment yielding dynamic varieties that contain potato genes only. It is envisioned that this CM approach with potato’s own genes will not only prove societally acceptable but may also result in simplifications in the legislation on use of the CM approach. Various parties in the potato research arena intend to cooperate in this novel approach in a number of developing countries where potato substantially contributes to food security. The use of resources such as land, water and energy improves when the effect of late blight is markedly reduced.     

Resistance to <Emphasis Type="Italic">Potato virus Y</Emphasis> in a Multitrait Potato Breeding Scheme without Direct Selection in Each Generation

In an experimental breeding scheme to improve late blight (Phytophthora infestans) and white potato cyst nematode (Globodera pallida) resistance of tetraploid potato over three generations of crossing and selection, 15 clones survived the final selection, and these were derived from 15 great-grandparents. There was no direct selection for resistance to Potato virus Y (PVY), but 14 out of the 15 great-grandparents were resistant to PVY and three had extreme resistance. Thirteen of the 15 descendants had PVY resistance and one extreme resistance. This was within the range expected for a random (unselected) sample from the genotypes of the great-grandparents. Hence, we found no evidence for any positive or negative association between PVY resistance and the attributes selected. The conclusion is that laborious selection is not required in every generation when many parents have PVY resistance, including some with more than one copy of a PVY resistance gene or resistance at more than one locus. However, in the future, determining the major virus resistance genes present in potential parents in each generation using diagnostic molecular markers would prevent susceptible × susceptible crosses being made and maximise the number of resistant × resistant ones.