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。     

天然芸苔素内酯减轻胺苯磺隆对水稻药害的作用

采用土培法在室内测定了不同浓度胺苯磺隆对水稻生长的影响，不同浓度天然芸苔素内酯对胺苯磺隆的解毒效应，以及不同浓度胺苯磺隆处理下天然芸苔素内酯浸种对水稻根生长的影响。结果表明，当天然芸苔素内酯浓度在0.01-0.05mg/L范围内时，可显著缓解1.0μg/kg的胺苯磺隆对水稻的药害，用0.02mg/L的天然芸苔素内酯种可不同程度地缓解0.1-20μg/kg的胺苯磺隆对水稻的药害。     

天然芸苔素内酯缓解胺苯磺隆对后茬水稻药害的作用机理初探

通过测定天然芸苔素内酯对水稻幼苗谷胱甘肽(GSH)含量、谷胱甘肽-S-转移酶(GST)活性以及在离体和活体条件下对水稻幼苗乙酰乳酸合成酶(ALS)活力的影响,研究天然芸苔素内酯减轻胺苯磺隆对水稻药害的作用机理。结果表明,其作用机理与水稻幼苗GSH含量、GST活性变化没有太大相关性,可能与其能间接激活水稻幼苗ALS活力有较大相关。     

芸苔素内酯类化合物的合成与分析方法研究进展

本文简要综述了芸苔素内酯的发现和几个常见易混淆的重要术语,以及我国登记的芸苔素内酯类化合物的种类、合成工艺和分析方法。     

赤·吲乙·芸解除胺苯磺隆对玉米药害的研究

赤·吲乙·芸是新一代的植物源植物生长调节剂,对植物生长有非常好的调节效果,而且能增强植物的抗旱,抗冻,抗虫,抗病性,在农业生产中有非常好的应用前景。本文以其解除胺苯磺隆对玉米的药害,对它作为安全剂的前景做了初步研究。     

0.01%芸苔素内酯对小麦经济性状及产量的影响

小麦是我国北方主要粮食作物 ,提高单产是栽培的重要环节 ,增加穗数、每穗粒数和千粒重是获得高产的基础。植物生长调节剂可以增加小麦穗数 ,防止倒伏 ,提高产量 ,在小麦的栽培中起着极其重要的作用。芸苔素内酯是一类重要的植物生长调节剂 ,在小麦栽培中有着广泛的用途。为了更好的使用芸苔素内酯 ,特进行了本次试验 ,现将结果报道如下。1　试验材料及方法试验小麦品种为“鄂恩 1号”,试验田为前茬水稻 ,地势平坦 ,肥力均匀 ,排灌方便。土壤类型为粘性壤土 ,p H值为 6.5 ,有机质含量 1 .9%左右。试验设每 hm2 0 .0 1 %芸苔素内酯 EC 0 .0…     

芸苔素内酯0.01%水剂调节黄瓜生长田间药效试验

进行田间试验以明确芸苔素内酯0.01%水剂对调节黄瓜生长的效果及最佳田间使用量。结果表明,在推荐用量为芸苔素内酯0.01%水剂有效成分为0.03～0.06 mg/kg时,在黄瓜移植后、初花期、结果期喷雾,即可收到良好效果。     

胺苯磺隆和灭草喹对水稻及玉米幼苗生长的影响

本文应用生物测定的方法研究胺苯碘隆和灭草喹对水稻、玉米幼苗生长影响。结果表明，①胺苯磺隆抑制水稻幼苗生长的临界浓度为１０＾－２ＰＰｍ，随着药剂浓度升高，抑制作用增大。不同水稻品种对胺苯磺隆的敏感性不同。籼、糯、粳稻的ＥＣ５０值分别为１．３１８、５．４８４和７５．４３１ｐｐｍ。②当胺苯磺隆的深度在１０＾－２ｐｐｍ以下时，对幼苗的生长具促进作用。     

芸苔素内酯在小麦上的应用效果

芸苔素内酯属激素类植物生长调节剂,可广泛应用于多种阔叶作物,如棉花、烟草及各种果蔬,均可有效地促进作物生长、提高产量,增强作物抗逆性。为了解芸苔素内酯在禾谷类作物上的应用效果,我们于2007年4—6月在武汉市江夏区五里界镇民主村进行了0．01％芸苔素内酯在小麦上的田间试验,并取得了较好的应用效果,增产4．93％～7．69％。现将试验结果整理如下。     

安全剂AD-67保护玉米免受单嘧磺隆药害的作用及其机理

采用生物测定法研究了安全剂AD-67对除草剂单嘧磺隆造成玉米伤害的保护作用,并对其作用机理进行了初步探讨。结果表明:单嘧磺隆在浓度0.025～0.050mg/kg时,对玉米的生长有较为强烈的抑制作用;当AD-67的浓度在0.5～10mg/kg时,能不同程度地缓解单嘧磺隆对玉米的药害。当单嘧磺隆毒土浓度为0.025mg/kg,使用1mg/kgAD-67浸种处理,玉米的主根长和株高分别是对照的107.3%和100.82%;AD-67浸种处理的玉米,幼苗中谷胱甘肽(GSH)含量和乙酰乳酸合成酶(ALS)活性分别是对照的109.76%和113.33%。     

The mechanism of linuron phytotoxicity in maize

The mechanism whereby Iinuron changes the functional and structural characteristics of chloroplast membranes was studied. The primary effect of the herbicide, the inhibition of phoiosynihetic electron transport results in an immuediatecessa-tion of carbon dioxide fixation and alterations in the membrane energization. These are accompanied by secondary processes contributing to phytotoxicity. The fundamental action in its phytotoxicity, as shown in a model system of isolated chloro-plasts, is the peroxidaiive breakdown of the polyunsaturated membrane lipids. This leads to destruction of the pigments, changes in the energy transfer, disorganization of the chloro-plast membranes, and accumulation of toxic organic peroxides.     

安全剂R-28725保护玉米免受氯磺隆药害的作用

采用生物测定法研究了安全剂R-28725保护玉米免受除草剂氯磺隆药害的作用.在氯磺隆毒土浓度为2 μg/kg时,使用5mg/kgR-28725浸种处理,玉米根部受到氯磺隆抑制的谷胱甘肽(GSH)含量由空白对照的57.3％恢复至83.4％;玉米叶片中乙酰乳酸合成酶(ALS)活性增加了17.2％;玉米根部的谷胱甘肽-S-转移酶(GST)活性增加了191.8％;GST酶促反应动力学参数Vmax增大102.5％,Km减小40.0％.结果显示:R-28725能够提高氯磺隆处理后玉米中GSH的含量,增加GST和ALS活性,增强了玉米根部GST酶对底物的亲和力,缓解氯磺隆对玉米产生的药害.     

安全剂R-28725保护玉米免受绿磺隆药害的机理

在盆栽和田间小区模拟条件下，测定了安全剂R-28725对玉米的株高和株鲜重的影响，确定了玉米体内GSH及其支链氨基酸的变化。结果发现：当绿磺隆的使用量为2．5、5、10g/hm^2时，R-28725能够明显提高玉米株高、株鲜重，混喷的效果显著高于其它处理。在绿磺隆的使用量为5g/hm^2时，使用R-28725混喷处理，玉米的产量为对照的101．68％。R-28725能够直接提高玉米幼苗中体内谷胱甘肽(GSH)含量，在绿磺隆浓度为1μg／kg，使用R-28725浸种处理，玉米幼苗中体内GSH含量增加27．83％，说明R-28725能够诱导绿磺隆与谷胱甘肽的轭合，从而达到解毒的目的。     

硝磺草酮对玉米药害的早期诊断和缓解方法

2006—2007年于北京市海淀区试验地开展了硝磺草酮对玉米不同品种的安全性及植物生长调节剂一碧护对药害的缓解作用方面的研究。以华北地区主栽的4个玉米品种为试材,按常规栽培习惯进行种植,小区面积60m^2。玉米4—5叶期,以0、105ga．i．／hm^2、210ga．i．／hm^2、420ga．i．／hm^2、840ga．i．／hm^2的剂量喷施硝磺草酮,施药7d后再按0和30g／hm^2的制剂用量喷施碧护。硝磺草酮的喷液量为600L／hm^2,碧护的喷液量为300L／hm^2施药后2d,玉米叶片的PPM值迅速降低,而随着时间的延长而逐步恢复,但不同玉米品种表现出较明显的差异。以白糯6号对药剂最敏感,需要10d才能恢复到正常水平;甜单8号次之,需要8d才能恢复;滑丰986和郑单21相对不是很敏感,需要6d恢复。处理后3～4d,玉米在硝磺草酮作用下,叶片白化,随用药量的增加而药害程度加重。硝磺草酮对玉米生长有较明显的抑制作用。随着施药剂量的增加,4个玉米品种的株高和鲜重均明显降低,且显著低于不用药的对照。喷施了碧护之后,玉米恢复程度有所加强,玉米株高明显增高。     

The phytotoxicity of various herbicides in two sandy loam soils and the effect of liming

The phytotoxicity of five soil-acting herbicides was investigated in two sandy loam soils and that of a further five herbicides in one of these soils. The effect of liming on phytotoxicity was also examined. Metoxuron, fenuron, metribuzin and fluometuron were more active in Boddington Barn soil than in Bledington soil. Prometryne was similar in effect in both soils. Liming significantly increased the effect of metoxuron in Boddington Barn soil and metoxuron, atraton, difenoxuron and metribuzin in Bledington soil. Monolinuron was less toxic in limed Bledington soil. Reasons for these differences have not been determined.     

The effect of plant-induced changes of pH upon the adsorption and phytotoxicity of s-triazlne herbicides

The effect of plant-induced changes of soluiion pH upon the adsorpiion of s-lriazme herbicides in either K-monimorillonite or Na - bentonite ciay-nutrieni suspensions and iheir phyioioxi- city in soil was studied. ln clay-NO₃^? suspensions (wiih NO₃- as the nitrogen source) maize planls (Zea may L.) caused a marked rise in solution pH and this resulted in a rapid descrp- tion of bound atrazine or simazine. in clay-NHa ⁺ suspensions (with NH4 ⁺ as the nitrogen source) the lowering of solution pH through plant aclivity resulted in jnereased adsorption of these herbicides. In soil, changes of rhizosphere pH were also found when either KNO₃ or (NH₄) ₂SO₄ were supplied as fertilizers, bul it was nol established whether ihis had a direct effeci upon the significant increase in weight of (NH₄)₂SO₄ treated wheat (Tri- ticum aestivum L.) planls at low herbicide concentrations compared with KNO₃ treated wheat plants.     

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.     

The phytotoxicity of some methylphosphonofluoridates

The phytotoxicity of some O-alkyl methylphosphonofluoridates has been studied by examining the effects of the compounds and their likely breakdown products on the germination of wheat seed and on the growth of wheat seedlings (14 to 18 days old) in hydroponic culture. The four O-alkyl methylphosphonofluoridates (ethyl; isopropyl; 3,3-dimethylbut-2-yl(pinacolyl) and cyclohexyl) were found to be phytotoxic and the phytotoxicity was shown to be a property of the compounds as such and not of their breakdown products. The phytotoxicity of the phosphonofluoridates was apparently influenced by the nature of the O-alkyl group and tended to increase as follows: ethyl <isopropyl < pinacolyl <cyclohexyl.