漫话腐植酸类农药

<正>在磺酰脲类除草剂系列产品中,如甲磺隆、氯磺隆、甲嘧磺隆、苄嘧磺隆、氯嘧磺隆、胺苯磺隆、烟嘧磺隆等既能作苗前处理(土壤处理)也能作苗后茎叶处理。有些产品如苯磺隆、噻嘧磺隆,只作茎叶处理,作土壤处理效果不好。因为相当部分磺酰脲类除草     

磺酰脲类除草剂成开发热点

<正>磺酰脲类除草剂由美国杜邦公司于20世纪80年代开发,目前在全球广泛应用。磺酰脲类的销量在除草剂市场仅次于氨基酸类(草甘膦、草胺磷等)位列第2。2009年销售额上亿的品种有苯磺隆、烟嘧磺隆、砜嘧磺隆、氯嘧磺隆、苄嘧磺隆、甲磺隆、碘甲磺隆、甲基二磺隆。     

除草剂安全用药月系列报道四:除草剂药害产生原因如何避免及挽救措施

<正>通常情况下,使用除草剂产生药害的原因有:误用或错用、施药设备受到污染、雾滴挥发与漂移、土壤残留对后茬作物影响、混用不当、除草剂降解产生有毒物质,异常不良环境等等。以最常用的使用范围最广的磺酰脲类除草剂为例,其对杂草有较高活性,可用于农田、林地及非耕地等防除杂草。但此类除草剂属于长残留性除草剂,使用后在土壤残留时间较长,即使有微量残留也易造成后茬敏感作物药害。磺酰脲类长残留性除草剂品种如氯磺隆、甲磺隆、胺苯磺隆、氯嘧磺隆、单嘧磺隆     

磺胺噻唑可作为开发油菜菌核病的防治药剂

<正>为开发新的油菜菌核病防治药剂,浙江大学农业与生物技术学院生物技术研究所选取7种乙酰乳酸合酶(ALS)潜在抑制剂(氯嘧磺隆、苄嘧磺隆、氯磺隆、甲嘧磺隆、咪唑乙烟酸、灭草喹和磺胺噻唑)作为3类ALS酶抑制剂(磺酰脲类、咪唑啉酮类、磺胺噻唑类)的代表,对其防治油菜菌核病的性能进行了测试。结果显示,1.0mg/L灭草喹、磺胺噻唑、氯嘧磺隆、苄嘧磺隆和氯磺隆对核     

几款磺酰胺类除草剂在我国的登记应用情况

<正>磺酰胺类除草剂是继磺酰脲类及后来发现的咪唑啉酮类除草剂之后,由美国陶氏农业科学公示研制开发的一类新型的乙酰乳酸合成酶(ALS)制剂剂。目前被成功开发并在世界范围内广泛推广应用的磺酰胺类包括唑嘧磺草胺、磺草唑胺、氯酯磺草胺、双氯磺草胺、双氟磺草胺、五氟磺草胺、啶磺草胺     

未来除草剂的明星产品——氯吡嘧磺隆的市场分析预测

<正>氯吡嘧磺隆适应作物非常广泛,可用于小麦、玉米、高粱、水稻、甘蔗、番茄、红薯、干豆、草坪和观赏作物,可用于住宅附近,同时对恶性杂草香附子特效,且能防除部分阔叶杂草。因此应用前景和推广价值非常高,未来将会有更多的厂家关注和申请登记。氯吡嘧磺隆除草剂是由日产化学公司研制、孟山都开发的一个新型磺酰脲类除草剂,是乙酰乳酸合成酶(ALS酶)的     

利用除草剂氯磺隆筛选转TSVPI基因玉米后代的方法

本研究以478玉米自交系及其转基因后代为材料,优化了除草剂筛选转基因玉米后代的方法.结果表明,当除草剂氯磺隆浓度为60 mg/L时,利用喷洒的方法可以在田间高效地淘汰大量非转基因植株和ALS(氯磺隆标记)基因表达量低的株系或个体.ALS基因作为除草剂筛选标记基因具有较高的生物活性、选择性强等优点.此方法可以用于转基因玉...     

氨基酸合成抑制剂类除草剂诱导油菜雄性不育效果评价

甘蓝型油菜对以乙酰乳酸合酶为靶标的磺酰脲类等除草剂很敏感, 其中部分除草剂具有很强的化学杀雄作用。本文通过油菜抽薹期叶面喷施试验, 比较26种能够抑制氨基酸生物合成的除草剂及复配剂对甘蓝型油菜雄蕊育性的影响。结果显示除过双草醚、麦喜、胺苯磺隆外, 其余23种除草剂均对油菜具有不同程度杀雄作用。其中600 mg hm^–2的咪唑乙烟酸、150mg hm^–2的吡嘧磺隆、240 mg hm^–2的烟嘧磺隆、200 mg hm^–2的单嘧磺隆和120 mg hm^–2的氯磺隆具有较高杀雄率, 但容易产生药害。而60~90 mg hm^–2的酰嘧磺隆、苯磺隆及其复配剂对油菜杀雄率大于95%, 持续时间长, 对雌蕊结实性能影响较小, 且在20个甘蓝型油菜品种(系)上杀雄效果稳定, 可以作为油菜等植物的最佳化学杀雄剂活性成分。本试验证明可以从氨基酸合成抑制型除草剂中筛选化学杂交剂, 为进一步开发化学杀雄剂提供了参考。     

绿黄隆残留对后茬水稻的二次药害及防止途径研究

绿黄隆(chlorsulfuron)是由美国杜邦公司于1980年开发的磺酰脲类超高效除草剂。该除草剂比绿麦隆、异丙隆等取代脲类除草剂具有用药量低、杀草力强、杀草谱广和对小麦较安全等特点,是目前麦田除草较理想的药剂。但它降解较慢,在田间有一定残留,若使用不当,对后茬作物会产生二次药害。为探究其残留对后茬水稻的安全性及防止残留药害的途径,我们对其进行了为期2年,(1988～1990年)的试验。     

除草剂的科学使用指南（续）

(接上期)⑥残效期长。氯磺隆、胺苯磺隆、莠去津、咪唑乙烟酸等除草剂在土壤中的残留量高,残效期长,易使旁茬或下茬作物受害,如38%莠去津悬浮剂亩用量260毫升以上,第二年除了玉     

Effect of Planting Sequence and Time, and Nitrogen on Maize Legume Intercrop Yield

Productivity of maize ( Zea mays L.) legume intercrops is determined by soil, management, and environment. Planting sequence and time and N fertilization are easily controlled management factors but their effects on intercrop yields are not well understood. Maize grown in monoculture or intercropped with polebean ( Phaseolus vulgaris L.) or cowpea ( Vigna unguiculata [L.] Warp.) was studied for two growing seasons at Morgantown, WV. Crops were seeded in the following sequences: maize before legume, both at the same time, and legume before maize. Planting times were early May or mid June. Nitrogen was applied at 0 or 160 kg ha⁻¹. Maize grain and forage, legume grain and forage, and total forage production were determined on a dry matter basis. Intercropping (average of all treatments) reduced maize grain and forage yields compared to maize in monoculture but had no effect on total forage production. However, total forage production was greatest when the seeding sequence was maize intercropped at the same time or before cowpea. Cowpea never produced grain, but forage production was almost double that of polebean. Maize produced most forage when seeded before the legumes, and the legumes produced most forage when seeded before maize. Early planting increased maize production and decreased legume production. Nitrogen increased maize grain, maize forage, and total forage yields but had not effect on legume forage production. It is concluded that maize/legume intercrops show promise for increasing forage production in temperate areas and more research on planting times and densities, weed control, harvesting and management is needed.     

Characterization of a Spontaneous Rapeseed Mutant Tolerant to Sulfonylurea and Imidazolinone Herbicides

A spontaneous chlorsulfuron tolerant variant, RCS-5, was isolated from protoplast culture of rapeseed, Brassica napus L. The tolerance level of the mutant was due to mutation of a single dominant gene resulting in an alteration of the acetolactate synthase enzyme. Seedling growth bioassays applied in vitro or after seed-soaking treatment showed that the mutant was 250——500 more tolerant to chlorsulfuron than the sensitive control. Field tolerance was evaluated with commercial formulations of chlorsulfuron (Glean T), triasulfuron (Kéos), and metsulfuron methyl (Allié), and an imidazolinone imazamethabenz (Méganet). The results indicated that the mutant could tolerate a lower dose rate of sulfonylureas than the dose recommended for cereal culture. In contrast, the mutation provided a good protection against imazamethabenz. The possibility of using the protoplast-derived mutation in crop rotation and F1 hybrid seed purity assessment is also discussed. However, isolated lines of the mutant were found to be less productive and one week later than the sensitive parent.     

Shade Effects on Phaseolus vulgaris L. Intercropped with Zea mays L. under Well-Watered Conditions

Field experiments were carried out under unstressed conditions of soil water during two summer crop growing seasons (1998–99 and 1999–2000 seasons) in a South African semi‐arid region (Bloemfontein, Free State, South Africa). The aim of this study was to investigate shade effects on beans intercropped with maize in terms of plant mass and radiation use. The experimental treatments were two cropping systems (no shading/sole cropping and shading/intercropping) and two row orientations (north–south and east–west). At the top of bean canopies shaded by maize, incident radiation was reduced by up to 90 %. Shading reduced total dry matter of beans by 67 % at the end of the growing season, resulting in yield losses. The dry matter partitioning into leaf and stem (the ratios of leaf and stem to total biomass) was about 50 % higher in intercropping than sole cropping. In contrast, intercropped beans had 40 % lower dry matter partitioning into pod (the ratio of pod to total biomass). Fraction of radiation intercepted by sole‐cropped beans steeply increased until canopy closure (0.9) and then slowly decreased, while fraction of radiation intercepted by intercropped beans remained constant between 0.0 and 0.2 throughout the growing seasons. However, intercropped beans had 77 % higher radiation use efficiency (RUE) than sole‐cropped beans. In contrast, for maize, no effect of intercropping (shading) was found on growth, partitioning, yield, radiation interception or RUE. Consequently, lower bean yield losses can be attained in association with late shading rather than early shading. This can be controlled by growing crops with different temporal and spatial treatments. As regards row treatment, no effect of row direction was found on growth, partitioning, yield, radiation interception or RUE.     

广西不同小菜蛾种群对印楝素和阿维菌素的敏感性研究

室内浸叶法测定结果表明:广西不同小菜蛾种群对印楝素的敏感性差异较小,LC50值在0.07￣0.23mg/L之间,与敏感性最低的石埠种群相比,相对毒力指数为1￣3.29;对阿维菌素对的的敏感性差异较大,LC50值在2.08￣17.02mg/L之间,与敏感性最低的仁乡种群相比,相对毒力指数为1￣8.18。     

The early stress response of maize (Zea mays L.) to chloride salinity

Chloride is a micronutrient required for photosynthesis but when applied in the concentration of a macronutrient, it may also promote growth by regulating turgor. However, if chloride accumulates excessively, it can induce toxicity. The aim of this study was to identify physiological dysfunctions in maize (Zea mays L.) that arise in response to excessive chloride ion accumulation. For this, a novel water sensor was employed for the first time allowing the in vivo measurement of water content in the plant by using two near IR‐wavelengths with different absorption of water. This enabled to analyse whether water imbalances occurred. Chloride was given together with calcium as companying counter cation. Results show that most of the tested maize genotypes were able to maintain growth, photosynthesis and normal water content when stressed with concentrations as high as 757.1 mg chloride/kg soil dry matter. Leaf blades accumulated only 8.5 mg chloride/g dry matter, with the most genotypes not even showing salt stress necrosis at the leaves. A comparison between more tolerant and more sensitive genotypes revealed that restriction of chloride root‐to‐shoot translocation is a trait of chloride tolerance.     

紫茎泽兰对两种牧草发芽的化感克异作用

研究了紫茎泽兰地上部分、根系及根际土壤不同浓度提取液对白三叶和多花黑麦草发芽的影响。研究结果表明：紫茎泽兰对白三叶和黑麦草种子萌芽存在化感克异现象，并且随浓度的增加，影响越大；相同条件下，对白三叶的影响强于多花黑麦草；低浓度对白三叶败育的影响较大，但对多花黑麦草几乎没有影响；紫茎泽兰根际土壤对两种牧草种子萌芽无明显的化感克异作用。     

高温对玉米籽粒淀粉合成及产量的影响

以农大108和山农3号为试材，采用田间生长箱增温的方法，研究了不同生育时期高温对玉米淀粉合成及产量的影响。结果表明，第1期（出苗后0~28 d）高温处理对玉米的产量没有显著影响，第2期（出苗后29~57 d）和第3期（出苗后58~86 d）高温处理显著降低玉米产量，以第2期对产量的影响最大；同时高温降低1,6-二磷酸酯酶（FBPase）、磷酸蔗糖合成酶（SPS）、蔗糖合成酶（SS）和腺苷二磷酸葡萄糖焦磷酸化酶（ADPGPPase）的活性，且以第2期降低的幅度最大；籽粒淀粉含量，以第1期高温处理高于对照，其他2个处理显著低于对照。     

Total phenolics and condensed tannins in field pea (Pisum sativum L.) and grass pea (Lathyrus sativus L.)

Seed samples of seventeen field pea cultivars grown at five locations, and nine grass pea lines grown at two locations, in western Canada during 1993 and 1994 were analysed for total phenolics and condensed tannins. Each location in each year was considered as one environment. Total phenolics in field pea differed significantly among cultivars, ranging from 162 mg/kg DM (dry matter) (CE, catechin equivalents) for AC Tamor to 325 mg/kg DM (CE) for Richmond. Field pea had barely detectable levels of condensed tannins. Total phenolics in grass pea ranged from 868 mg/kg DM (CE) for L880388 to 2059 mg/kg DM (CE) for LS89110. Condensed tannins in grass pea ranged from 0.89 g/kg DM (CE) for L880388 to 5.18 g/kg DM (CE) for LS89125. Cultivar had a larger relative contribution to total phenolic levels in field pea and to total phenolic and condensed tannin levels in grass pea than environment. Total phenolic and condensed tannin levels were not correlated with seed yield and seed protein content in field pea or grass pea. Levels of total phenolics and condensed tannins were positively correlated in grass pea. Grass pea seeds with darker seed coat colour contained higher levels of condensed tannins. This revised version was published online in July 2006 with corrections to the Cover Date.     

低磷胁迫对玉米自交系齐319和其突变体齐319-96叶片光合作用、叶绿素荧光特性的影响

为了解低磷胁迫下不同磷利用效率玉米叶片在光能的吸收、分配和过剩激发能的耗散方面的差异,以利用细胞工程技术获得的不同磷利用效率玉米齐319 和Qi319-96 为材料,采取水培的方法,研究了低磷(KH2PO4 5 μmol/L,-P)和正常供磷(KH2PO4 1000 μmol/L,+P) 2 个供磷水平对玉米叶片的光合作用及叶绿素荧光参数的影响。结果表明：低磷胁迫下突变体齐319-96 叶片的光能转换和电子传递效率高于玉米自交系齐319;突变体齐319-96 叶片吸收的光能用于光化学反应部分显著高于齐319;通过天线热耗散部分的能量低于齐319;二者通过其他途径耗散过剩光能的部分差异不显著。叶片通过活性氧清除系统对过剩光能耗散作用在自交系齐319 和突变体齐319-96 间差异不显著。低磷胁迫下与齐319 相比,突变体齐319-96 叶片中的无机磷含量显著提高。与自交系齐319 相比低磷下自交系齐319-96具有更高的光能利用效率和碳同化速率,推测不同磷效率玉米自交系之间光合特性差异与叶片中无机磷含量的差异有关。     

Genetic variability in tolerance to cadmium and accumulation of heavy metals in pea (Pisum sativum L.)

Ninety-nine wild growing and primitive varieties of garden pea (Pisum sativum L.) were screened for tolerance to cadmium (Cd) toxicity in quartz sand culture. Cadmium tolerance was determined by the time to plant death when treated with a lethal Cd concentration (13 mg kg^-1), and by a tolerance index (TI) calculated as a ratio between biomasses of Cd-treated and untreated plants in the presence of toxic Cd concentrations (7 mg kg^-1 and 5 mg kg^-1). The Cd-tolerance index varied significantly between pea genotypes from 35% to 90% and from 54% to 100% in the presence of 7 and5 mg Cd kg^-1, respectively. Shoot Cd concentration of tolerant and sensitive genotypes grown in the presence of 5 mg Cdkg^-1 varied between 35 mg Cd kg^-1and 135 mg Cd kg^-1 (dry weight) and was negatively correlated with TI. Certain tolerant pea genotypes were characterized by a high Cd concentration in shoots. All varieties were also screened for their ability to take up heavy metals (HMs) from a slightly contaminated soil. The concentration of Cd, chromium, copper, nickel, lead, strontium and zinc in plant shoots varied between pea genotypes by a factor of 2.8, 4.9, 2.7, 3.5, 9.7, 3.9 and 4.0, respectively. The coefficients of variation between pea genotypes for HM concentration were high, varying from 23%to 39% depending on the metal. The distribution patterns for varieties based on Cd tolerance (sand culture) and HM concentrations (soil culture) were characterised by positive skewness coefficients, suggesting that the majority of pea genotypes was relatively sensitive to Cd toxicity and tended to avoid excessive accumulation of HMs in shoots. These results show that a high genetic variability exists in pea with regards to Cd tolerance and HM accumulation. Concentrations of different HMs in plants grown in soil correlated positively with each other, with the exception of chromium. There was no correlation between Cd tolerance of the varieties in sand culture, shoot concentration of HMs in soil culture, biomass production, subspecies and geographical origin of the varieties. The genetic systems controlling Cd tolerance, HM accumulation and morphological traits are therefore independent to some extent, suggesting a possibility for breeding pea cultivars characterised by high tolerance to and low concentration of HMs in shoots. This revised version was published online in August 2006 with corrections to the Cover Date.