乙烯利对草甘膦在空心莲子草中传导及生物活性的影响

在人工气候室培养空心莲子草,植株经草甘膦与乙烯利混合处理后,测定对植株的抑制作用和草甘膦的吸收与传导量.结果表明,加入乙烯利(100 mg*L-1)后草甘膦(300mg*L-1)对地下根茎抑制率比对照提高了13.6个百分点.植株经乙烯利喷雾处理后,基芽、地下茎和根系中14C-草甘膦含量分别是对照的3.56、1.75和2.35倍.放射性成像图显示,植株地下茎与根系中14C-草甘膦传导量明显高于对照.     

硫酸铵对草甘膦在空心莲子草中输导及除草活性的影响

草甘膦与硫酸铵混合后处理空心莲子草,测定其对植株的抑制作用和体内草甘膦的吸收与传导量。结果表明,加入硫酸铵(1.20 g/L)后草甘膦(300 mg/L)对地下根茎抑制率比对照提高了12.2个百分点。植株经硫酸铵喷雾处理后,地下茎和根系中14C-草甘膦含量分别是对照处理的1.39和1.86倍。药液中水的硬度达到342.0 mg/L时明显降低草甘膦的除草活性,硫酸铵浓度达到12.0 g/L则可基本消除水的硬度对草甘膦除草活性的影响。     

有机硅喷雾助剂对草甘膦在空心莲子草上的沉积和生物活性的影响

研究了有机硅喷雾助剂(OSA)对草甘膦在空心莲子草Alternanthera philoxeroides上的沉 积与生物活性的影响。当采用较大喷雾雾滴,施药液量高于632.5 L/hm2时,添加OSA(0.35 g/L) 后,草甘膦药液在空心莲子草上的沉积量显著下降。最大稳定持留量(MRG)由未添加OSA的0.61~0.63 μ L/cm2下降到0.50~0.54 μ L/cm2。分别以33.7和67.4 μ g/株剂量的草甘膦点叶处理空心莲子草,发现添加OSA的处理对再生植株茎叶生长的抑制率分别比对照提高了8.89%和14.83%。草甘膦(有效成分199.3 g/hm2)施药后1 h进行人工模拟降雨处理,添加OSA后药剂对空心莲子草的生物活性比无OSA对照处理提高了20.5%。研究结果表明,添加有机硅喷雾助剂促进了草甘膦在空心莲子草中的向下传导性能,提高了草甘膦水剂在空心莲子草叶片的耐雨水冲刷性能,但会降低草甘膦药液在空心莲子草上的最大稳定持留量。     

低镁胁迫对马铃薯试管苗碳水化合物积累和分配的影响

以马铃薯品种"大西洋"的试管苗为材料,在5个不同镁浓度(0、188、375、750、1 500μmol·L~(-1))的MS培养基上培养,20 d后测定生理和形态指标,研究了低镁胁迫对马铃薯试管苗叶绿素含量和碳水化合物积累与分配以及根系形态建成的影响。结果表明:试管苗的总叶绿素、叶绿素a(Chla)和叶绿素b(Chlb)含量以及根冠比、总根长、根表面积、根体积和侧根数均为缺镁(0μmol·L~(-1))处理最低,分别比对照(1 500μmol·L~(-1))降低42.3%、40.8%和46.2%以及96.4%、63.9%、54.1%、82.4%和89.9%;平均根直径和Chla/Chlb值为缺镁处理最高,分别较对照增加16.7%和9%;茎叶中淀粉、蔗糖、果糖和可溶性糖含量以及根中蔗糖、果糖和可溶性糖含量均为缺镁处理最高,分别比对照增加了58.5%、54.8%、59.7%和25.9%以及22%、46.7%和54.7%,而根中淀粉含量为缺镁处理最低,较对照降低32.8%。相关性分析表明,马铃薯试管苗茎叶中淀粉、果糖和可溶性糖含量与镁浓度均呈显著负相关。说明缺镁影响马铃薯试管苗的光合作用和碳水化合物代谢,大量碳水化合物在茎叶中积累,向根部的运输量减少,侧根形成减少,根冠比降低,抑制根系的形态建成。低镁水平下(750μmol·L~(-1))试管苗的叶绿素含量增加,更多的碳水化合物向根部运输,根冠比增大,促进根系的形态建成,与正常镁水平(1 500μmol·L~(-1))下马铃薯试管苗指标变化相同,差异不显著,表明含750μmol·L~(-1)Mg~(2+)的MS培养基适宜于马铃薯试管苗的生长和发育。     

芸苔素内酯保护玉米免受胺苯磺隆伤害的作用及其机理

采用土培法和田间小区试验法测定了芸苔素内酯(BR)对玉米的保护作用,并对其作用机理进行了初步研究。结果表明:BR 的浸种浓度在0.01～0.04mg·L~(-1)范围内,能不同程度地缓解16.0μg·kg~(-1)胺苯磺隆对玉米的药害,BR 浓度为0.02mg·L~(-1)时,解毒效果最好。用0.02mg·L~(-1)的 BR 浸种,能不同程度地缓解2.0～32.0μg·kg~(-1)的胺苯磺隆对玉米生长的抑制,但当胺苯磺隆浓度增加到64.0μg·kg~(-1)时,BR 浸种无解毒作用;按15g ai/hm~2的剂量施用胺苯磺隆对玉米的减产率达11.8％,用BR 0.02、0.04 mg·L~(-1)浸种处理则减产率分别为0.2％和0.1％;BR 提高胺苯磺隆处理的玉米幼苗中 ALS 活性可能是其保护玉米免受胺苯磺隆伤害的机理之一。     

三种杂草对草甘膦的敏感性及处理后植株体内莽草酸积累量差异

为明确不同杂草对草甘膦的敏感性,以稗 Echinochloa crusgalli 、马唐 Digitaria sanguinalis 、藜 Chenopodium album 为供试材料,采用生物测定法和吸光光度法分别测定了草甘膦对3种杂草的抑制中浓度(GR50),以及不同剂量处理后杂草体内莽草酸积累量的变化。经410 g/hm2(有效成分)的草甘膦处理后,稗体内莽草酸积累量呈上升-下降-上升趋势,而马唐和藜则表现为缓慢上升,根据此剂量处理下莽草酸积累趋势得出,3种杂草对草甘膦的敏感性由高到低依次为稗、藜和马唐,与生测法的结果一致。经820~3 280 g/hm2(有效成分)的草甘膦处理后,3种杂草体内莽草酸积累量从第2 d开始急剧升高,增长速率随着草甘膦处理剂量的增加而加大;处理后稗、马唐和藜体内莽草酸积累量最高值差异显著,分别为1 137.9、4 989.7和2 084.2 μ g/g,为各自对照水平的16.7、23.7和82.9倍。该研究结果可为系统检测杂草对草甘膦的敏感性提供依据。     

甘露醇和烯效唑对培育马铃薯试管壮苗的影响

用不同浓度甘露醇和烯效唑处理马铃薯试管苗,来探究在组织培养条件下甘露醇和烯效唑对培育马铃薯试管苗壮苗的影响。试验设置对照组(CK)和处理组,处理组分别A(10 g·L~(-1)甘露醇)、B(20 g·L~(-1)甘露醇)、C(30 g·L~(-1)甘露醇)、D(40 g·L~(-1)甘露醇)、E(0.001 mg·L~(-1)烯效唑)、F(0.002 mg·L~(-1)烯效唑)、G(0.003mg·L~(-1)烯效唑)和H(0.004 mg·L~(-1)烯效唑)9个水平,分别在第30天和第60天取样测定。结果表明,培养30 d和60 d后,适宜浓度甘露醇(20 g·L~(-1))和烯效唑(0.003 mg·L~(-1))处理马铃薯试管苗,植株矮化(株高:82.54±3.84 mm和67.41±1.67 mm,30 d;93.74±1.30 mm和68.78±1.16 mm,60 d)且茎增粗(茎粗:1.45±0.03 mm和1.32±0.05 mm,30 d;1.80±0.13 mm和1.65±0.03 mm,60 d),鲜重达最大值(鲜重:1.35±0.04 g和1.32±0.04 g,30 d;1.75±0.09 g和1.53±0.04 g,60 d),马铃薯试管苗根长、根粗、根表面积和根体积也显著高于对照;同时,该处理下试管苗抗氧化酶超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性均达最大值。由此可知,甘露醇和烯效唑能促进马铃薯试管苗增粗矮化生长,使试管苗根系较发达,组织培养抗氧化酶活性增强,降低了活性氧对马铃薯试管苗造成的伤害,从而有利于培育壮苗。     

14 C-标记腈菌唑的合成及其在小麦幼苗上的吸收与传导确证

以14C标记碳酸钡(Ba14CO3)为起始物,采用4步反应合成14C-1,2,4-三唑,总强度为5.813 1 mci,比强为15.53 μci/mg, 纯度大于99%,放化收率84.21%。在此基础上,参照文献报道的有关腈菌唑合成的方法,以4-氯苯乙腈为原料,经取代、缩合等3步反应合成了14C-腈菌唑,其总强度为0.556 6 mci,比强为2.53 μci/mg,纯度大于96%,放化收率85.4%。应用同位素示踪技术研究了14C-腈菌唑在2~3叶期小麦幼苗上的吸收、分布和传导。结果表明,根部给药后6~120 h,小麦根部放射性物质分布比例由59.88%下降为 24.87%;在幼苗茎基部和叶片中,放射性物质分布比例分别由14.18%、1.19%上升为 19.47%和33.75%;14C-腈菌唑被小麦幼苗吸收后向顶传导的速度很快,在叶片中的分布和积累与根部给药时间呈正相关,放射强度由2.94×10-6 μci上升为322.72×10-6 μci。放射性自显影表明,根部给药后120 h,14C-腈菌唑可以内吸传导到整个小麦植株。     

非衍生化超高效液相色谱-串联质谱法快速检测环境水中强极性农药及其代谢物

建立了一种简便、直接进样、非衍生化超高效液相色谱-串联质谱 (UPLC-MS/MS) 快速测定环境水样中乙烯利、草甘膦、草铵膦及其代谢物等6种强极性化合物残留的分析检测方法。环境水样经离心、过滤后，无需衍生，直接进样进行定量分析。样品经Waters Acquity UPLC HSS T3色谱柱 (100 mm × 2.1 mm，1.8 μm) 分离，以0.1%甲酸-5 μmol/L亚甲基二膦酸水溶液、甲醇为流动相，在电喷雾离子源、正离子扫描和多反应监测模式 (MRM) 下进行分析，外标法定量。结果表明:6种化合物在各自线性范围内具有良好的线性关系，决定系数 (R2) 均大于0.99，在10~200 μg/L添加水平下，6种化合物在环境水样中的平均回收率在75%~100%之间，日内相对标准偏差与日间相对标准偏差（n=6）分别为3.6%~7.0%和4.3%~7.5%。方法定量限在0.5~10.0 μg/L之间。利用所建立的方法对3个地区10份地表水样进行检测。结果显示:乙烯利、草甘膦、草铵膦及其代谢物等6种化合物均未检出。该方法与衍生化方法相比，具有简便快速、重现性好、灵敏度高等优点，可以为环境水中乙烯利、草甘膦、草铵膦及其代谢物等强极性化合物检测提供参考。     

根施外源甜菜碱对胡杨幼苗叶片积累甜菜碱与耐盐特性的影响

在不同盐分处理下(0、100、200、300、500 mmol·L~(-1)Na Cl)对土壤进行盆栽实验,研究根施甜菜碱(GB,5 mmol·L~(-1))对1 a生胡杨(Populus euphratica)幼苗叶片甘氨酸甜菜碱(GB)积累特性与不同时间(第7天、第14天)光合作用的影响。结果表明:(1)盐胁迫单独处理下,相比对照(0 mmol·L~(-1)Na Cl,CK)叶片甜菜碱随盐胁迫强度增大积累量显著增多。盐胁迫和外源GB双重处理下,叶片GB含量总体趋势随盐浓度升高表现为先升高后保持平稳。在低盐胁迫处理时(100~300 mmol·L~(-1)Na Cl)外源GB能诱导叶片产生更多GB,较未经GB处理组叶片GB积累量分别提高44.0%、32.5%和35.9%,而高盐胁迫(500 mmol·L~(-1)Na Cl)则转为抑制,叶片GB含量降低了5.1%。(2)随着盐浓度升高,外源GB虽不能持续促进叶片GB含量,但其对光合维持能力却没有丧失。随着胁迫强度增加,外源GB对叶绿素含量、水分利用效率(WUE)、叶片相对含水量(RWC)及相关光合参数的维持作用越明显。(3)不同时间下盐分和外源GB对胡杨光合作用的影响会改变,外源GB先维持胡杨水分传递过程,后维持CO_2同化能力,最终提高其光合作用。总之,根施GB能够促使胡杨叶片GB积累量发生变化并发挥作用,调节盐胁迫下胡杨光合相关生理过程从而提高其耐盐能力。     

Influence of picloram on Cirsium arvense (L.) Scop, control with glyphosate

Low rates of picloram in mixture with glyphosate provided a rapid enhancement of the onset of injury to the shoots of Cirsium arvense (Canada thistle or creeping thistle) under field (0.07+1.0 and 0.07+1.5 kg ha^?1) and greenhouse (0.035+0.42 and 0.07+0.84 kg ha^?1) conditions. Picloram slightly reduced the amount of ¹⁴C-glyphosate absorbed at 24 and 48 but not 72 h after treatment. Movement of ¹⁴C-glyphosate from the treated leaves to the shoot apex, remainder of the shoot and roots was reduced in the presence of picloram. Necrosis of the treated leaves above the treated spots was evident, presumably indicating acropetal movement of either or both herbicides. With the picloram + glyphosate mixtures there was increased shoot regrowth over glyphosate alone at 1 year after treatment under field, and with certain mixtures at 18 days and 4 weeks after treatment under greenhouse conditions. Following application of the mixtures, accumulation of glyphosate in the shoots may be responsible for the enhanced onset of shoot injury while failure of enough glyphosate to translocate to, and cause death of, the roots may be responsible for the increased shoot regrowth over glyphosate alone.     

Fate of glyphosate in Agropyron repens (L.) Beauv. growing under low temperature conditions

Absorption, translocation and distribution of ¹⁴C-glyphosate were examined in Agropyron repens (L.) Beauv. plants growing under field conditions in the autumn. Glyphosate absorption did not increase beyond 3 days after application, whereas translocation to the rhizomes continued up to 7 days after application. The translocated glyphosate accumulated more in new rhizomes than in older parts of the rhizomes. Ten per cent of the glyphosate translocated out of the treated shoot was recovered in younger shoots 7 days after application. Plants harvested the following spring contained less than 20% of the glyphosate originally applied. Although a growth cabinet experiment indicated that 34% of the glyphosate in the rhizomes of treated plants could be remobi-lized into new aerial shoots, considerably less was recovered in new, aerial shoots in the spring in the field-grown plants. Freezing experiments showed that glyphosate translocation to the rhizomes was only prevented when cold treatment caused visible damage to A. repens foliage.     

Differential phytotoxicity of glyphosate in maize seedlings following applications to roots or shoot

The transport and differential phytotoxicity of glyphosate was investigated in maize seedlings following application of the herbicide to either roots or shoots. One-leaf maize seedlings (Zea mays L.) were maintained in graduated cylinders (250 mL) containing nutrient solution. Half of the test plants were placed in cylinders (100 mL) containing different ¹⁴C-glyphosate concentrations; the remainder received foliar appliation of ¹⁴C-glyphosate. After 26 h, the roots and the treated leaves were washed with distilled water, and the plants placed again in cylinders (250 mL) containing fresh nutrient solution for 5 days. Plants were weighed, and split into root, seed, cotyledon, coleoptile, mesocotyl, first leaf and apex. The recovery of ¹⁴C-glyphosate was over 86%. For both application treatments, the shoot apex was the major sink of the mobilized glyphosate (47.9 ± 2.93% for root absorption and 45.8 ± 2.91% for foliar absorption). Expressed on a tissue fresh weight basis, approximately 0.26 μg a.e. g⁻¹ of glyphosate in the apex produced a 50% reduction of plant fresh weight (ED₅₀) when the herbicide was applied to the root. However, the ED₅₀ following foliar absorption was only 0.042 μg a.e. g⁻¹ in the apex, thus maize seedlings were much more sensitive to foliar application of the herbicide.     

Effects of two surfactant series on the absorption and translocation of 14C-glyphosate in sicklepod and prickly sida

The weed species, prickly sida (Sida spinosa L.) and sicklepod (Senna obtusifolia L.), were treated with ¹⁴C-glyphosate alone and formulated with different polyethlylane oxide (PEO) surfactants in tallow amine ethoxylate and non-ionic alkoxylate series to determine the amount of ¹⁴C-glyphosate absorption and translocation. The surface tension, contact angle, and ¹⁴C-glyphosate distribution were significantly affected by both the presence of different waxes on the plants and by the addition of surfactants to the glyphosate. The surface and contact angle values of the surfactants, with and without glyphosate, showed a significant increase as the PEO number increased in both surfactant series. A higher absorption of the ¹⁴C-glyphosate was recorded for S. spinosa compared with S. obtusifolia. The absorption and translocation of the ¹⁴C-glyphosate increased with the increase in the PEO number of tallow amine ethoxylate. In the case of the non-ionic alkoxylate surfactant series, an increase in the absorption of ¹⁴C-glyphosate was recorded when the surface tension and contact angle values decreased. There was no significant difference in the translocation values obtained in the two species after the addition of the surfactants. The amount of ¹⁴C-glyphosate absorbed by the treated leaf was significantly higher in the case of S. spinosa compared with S. obtusifolia. A linear relationship was observed with the physical properties, ¹⁴C absorption, and the efficacy of glyphosate with the addition of the non-ionic alkoxylate surfactant series. The percentage control was higher with the higher PEO surfactant in the tallow amine ethoxylate surfactant series and with the lower PEO surfactant in the non-ionic alkoxylate surfactant series as the two series are chemically different.     

Selectivity of glyphosate in creeping red fescue and reed canarygrass*

The differential tolerance of resislant creeping red fescue (Fes- tuca rubra L, var, rutra) and susceptibie reed canarygrass (Pha- laris arundinacea L.) seedlings to glyphosate [N-(phosphono- meihyDglycine) was confirmed under growth chamber condilions. The absorption, transiocation and metabolism of ¹⁴C-glyphosate was examined in both species to determine if differences in these processes could account for the observed selectivity, Creepmg red fescue actually absorbed more glyphosate than did t-eed canarygrass, and both species rapidly translocated the herbicide throughout their respective tissues. No metabolism of glyphosate was detected in either species. Differential interception and retention of the glyphosate spray can probably be eliminated as possible selectivity mechanisms. The relative tolerance of creeping red fescue to glyphosale appears to be related to its ability lo regenerate roots and shoots from the crown of the plant, but the mechanism of resistance remains obscure.     

Absorption,translocation and metabolism of 14C-glyphosate in several weed species*

The pattern and extent of ¹⁴C-glyphosate [N-(phosphonomethyl)glycine] translocation from the treated leaf and metabolism of ¹⁴C-glyphosate were studied in field bindweed (Convolvulus arvensis L.), hedge bindweed (Convolvulus sepium L.). Canada thistle [Cirsium arvense (L.) Scop.] tall morning glory [lpomoea purpurea (L.) Roth.] and wild buckwheat (Polygonum convolvulus L.). ¹⁴C was translocated throughout the plants within 3 days with accumulation in the meristematic tips of the roots and shoots evident. Cross and longitudinal sections of stems and roots showed that the ¹⁴C was localized in the phloem. Field bindweed translocated 3–5% of the applied ¹⁴C from the treated leaf, hedge bindweed 21.6%, Canada thistle 7.8%, tall morningglory 6.5%, and wild buckwheat 5%. Field bindweed, Canada thistle, and tall morningglory metabolized the parent glyphosate to aminomethylphosphonic acid to a limited extent. This metabolite made up less than 15% of the total 14C. Of the total ¹⁴C applied to excised leaves, 50% had disappeared within 25 days.     

Basis for changes in glyphosate phytotoxicity to barley by the non-ionic surfactants Tween 20 and Renex 36*

The non-ionic surfactants, Tween 20 (polyoxy-ethylene 20 sorbitan monolaurate) and Renex 36 (polyoxyethylene 6-tridecyl ether) enhanced the retention of a glyphosate-dye spray solution by barley (Hordeum vulgare L.) leaves. Tween 20 also enhanced absorption of ¹⁴C-glyphosate applied as droplets to barley leaves whereas Renex 36 similarly applied, reduced both absorption and movement of ¹⁴C-glyphosate. Renex 36 alone or mixed with glyphosate increased leakage of electrolytes from barley leaf segments whereas neither Tween 20 nor glyphosate, alone or mixed together, had any effect. No ¹⁴C-glyphosate complexes were detected in mixtures with either surfactant and neither surfactant affected the pH of the glyphosate solution. The results indicate that the reported enhancement of glyphosate phytotoxicity by Tween 20 is due to increased retention and absorption of the herbicide while the reported antagonism caused by Renex 36 is due to reduced glyphosate absorption and movement possibly as a result of alteration of membrane integrity.     

Uptake and translocation of 14C-glyphosate in Alternanthera philoxeroides (Mart.) Griseb. (alligator weed) I. Rhizome concentrations required for inhibition

Rhizome segments from Alternanthera philoxeroides were shaken in solutions of ¹⁴C-glyphosate for 24 h to establish a range of internal tissue concentrations. Rhizomes were killed at concentrations of 16 μg g^?1 dry weight and above and survived at concentrations of 8 μg g^?1 dry weight and below. Plants grown in the field for 10 weeks in declining photoperiod were used to investigate the uptake and translocation of ¹⁴C-glyphosate after application of a constant dosage in either 1.0-or 0.2-μl droplets corresponding to concentrations of 1.06 and 5.3 g 1^?1, of glyphosate acid, respectively. Use of smaller droplets of higher concentration increased absorption of ¹⁴C, but did not improve translocation. Uptake by treated leaves was 25 and 41% of the applied glyphosate for the large and small droplets respectively, but translocation to underground parts of the plant was about 7% of applied ¹⁴C-activity. Radiolabel accumulated in new rhizomes was equivalent to about 0.5 μg g^?1 dry weight of glyphosate, at least 30 times below the concentration required for tissue death. Absorption et transport de glyphosate C14 chez Alternanthera philoxeroides (Mart.) Griseb. I.Concentrations dans les rhizomes nécéssaires pour l'inhibition Des fragments de rhizome d'Alternanthera philoxeroides ont été trempés dans des solutions de glyphosate C14 pour aboutir à un éventail de concentrations internes des tissus, Les rhizomes ont été tués à des concentrations de 16 μg g^?1 PS et plus, et ont survécu à des concentrations de 8 μg g^?1 PS et en-dessous. Des plantes cultivées en plein champ pendant 10 jours en photopériode décroissante ont été utilisées pour étudier l'absorption et le transport du glyphosate C14 après l'application d'une dose constante dans des gouttelettes de 1 ou 0,2 μl correspondant à des concentrations de 1,06 et 5,3 g l^?1 de glyphosate C14 acide respectivement, L'utilisation de gouttelettes plus petites de concentrations plus é1evées a augmenté l'absorption du C14, mais n'en a pas amélioré le transport. L'absorption par les feuilles traitées était de 25 et 41% du glyphosate appliqué pour les grandes et les petites gouttelettes respectivement, mais le transport vers les parties souterraines de la plante était d'environ 7% du C14 appliqué. Le radio-marqueur dans les nouveaux rhizomes était équivalent à environ 0,5 μg g^?1 PS de glyphosate, soit au moins 30 fois en-dessous de la concentration nécessaire à la mort des tissus. Aufnahme und Translokation von ¹⁴C-Glyphosat in Alternanthera philoxeroides (Mart.) Griseb. I. Für die Hemmung erforderliche Konzentration im Rhizom Rhizomteile von Alternanthera philoxeroides wurden 24 Stunden lang in ¹⁴C-Glyphosat-Lösungen geschüttelt, um eine Reihe von Konzentrationen in den inneren Geweben einzustellen. Die Rhizome wurden bei Konzen-trationen von 16 und mehr μg g^?1 TM abgetötet und überlebten bei Konzentrationen von 8 μg g^?1 TM und weniger. Die Aufnahme und Translokation von ¹⁴C-Glyphosat nach der Applikation einer konstanten Dosis in 1,0-oder 0,2-μl-Tröpfchen, entsprechend Konzentrationen von 1,06 und 5,3 g l^?1 Glyphosat-Säure, wurden an Pflanzen untersucht, die im Freiland 10 Wochen lang bei abnehmender Photoperiode gewachsen waren. Der Gebrauch kleinerer Tropfen höherer Konzentration führte zu mehr Absorption von ¹⁴C, förderte aber nicht die Translokation. Das Glyphosat wurde von den behandelten Blättern zu 25 bzw. 41% aus den großen Oder den kleinen Tröpfchen aufgenommen, aber die Translokation in die unterirdischen Pflanzenteile war etwa 7% der ausgebrachten ¹⁴C-Aktivität. Die in neuen Rhizomen akkumlierte Radioaktivität entsprach 0,5 μg g^?1 TM Glyphosat, mindestens 30mal weniger als für die Abtötung von Gewebe erforderlich.     

9种除草剂对花生白绢病菌的影响

在实验室条件下测定了氟乐灵、乙草胺、异丙甲草胺、异恶草酮、乳氟禾草灵、乙氧氟草醚、三氟羧草醚、恶草酮、二甲戊乐灵等9种除草剂对花生白绢病菌Sclerotium rolfsi Sacc.的影响.结果表明:9种除草剂对花生白绢病病菌的毒力有较大差异,三氟羧草醚和乙氧氟草醚的毒力较高,IC50分别为7.88mg·L-1和18.91mg·L-1;9种除草剂对菌丝干重均有抑制作用,且随剂量的升高而升高,乙氧氟草醚和三氟羧草醚抑制作用最明显,在100mg·L-1和50mg·L-1时抑制率均达90%以上;除乙草胺和异丙甲草胺部分剂量外,其他除草剂对菌核数量均有不同程度的抑制作用,三氟羧草醚作用最为明显,在供试剂量下抑制率均达96%以上;除乙草胺、氟乐灵在供试剂量下对菌核单重有抑制作用外,其他除草剂在多数剂量下对菌核单重均有刺激作用,三氟羧草醚在50mg·L-1时,是对照菌核单重的8.34倍;而各种除草剂在供试剂量下,对菌核萌发均没有影响.     

Uptake, translocation and phytotoxicity of imazapyr and glyphosate in Imperata cylindrica (L.) Raeuschel: effect of herbicide concentration, position of deposit and two methods of direct contact application

The activity of imazapyr and glyphosate against Imperata cylindrica was studied in field and glasshouse experiments using two methods of direct contact application; a rope-wick wiper and a cloth soaked in herbicide solution. The effect of concentration and position of application on herbicide uptake and translocation was also measured. At the lowest dose of imazapyr (5 mg acid equivalent (a.e.) per plant), phytotoxicity was greater from applications by a rope-wick wiper than by a cloth. However, when the dose of imazapyr was increased, the cloth applicator was more effective than the rope-wick wiper. At all doses of glyphosate, rope-wick application was more effective than wiping with a cloth. Herbicide performance in the glasshouse was similar to that in the field. Radiotracer studies showed that increasing the concentration of imazapyr, while keeping herbicide dose constant, decreased uptake and translocation of radiolabel. In contrast, the rate of uptake of ¹⁴C-glyphosate increased with increasing herbicide concentration. Position of application did not significantly affect the amount of uptake and translocation of radiolabel to the rhizomes. It is concluded that rope-wick wipers are more effective than wiping with a cloth for applying imazapyr and glyphosate to I. cylindrica, provided that the concentration of imazapyr does not exceed 10 g a.e. l^?1.