固相抗体直接竞争EL ISA 法测定氯黄隆在土壤中的残留动态

采用包被抗体直接竞争EL ISA 法测定了氯黄隆在盆土中的残留动态和农田土壤中氯黄隆的残留量。结果表明: EL ISA 法测定土壤中氯黄隆的检测限2、45 g/ hm2 第一年麦收时中性沙质土壤和弱碱性沙壤土中氯黄隆的残留量分别为0. 24、0. 56 ng/g 和0. 30、0. 96 ng/g, 第二年分别为0. 28、0. 67 ng/g 和0. 38、1. 09 ng/g , 与平行进行的高效液相色谱法、生物测定法测定结果基本一致。     

Effect of certain herbicides on growth and pathogenicity of take-all fungus on wheat (Triticum aestivum L.)

Summary The effects of Spray Seed (diquat + paraquat), Roundup (glyphosate), Banvel-D (dicamba), Treflan (trifluralin), Glean (chlorsulfuron) and Dacthal (chlorthal dimethyl) at concentrations of 0–500 ppm product on the vegetative growth, vigour and pathogenicity of Gaeumannomyces graminis var. tritici (Ggt) on wheat were examined. All herbicides with the exception of dicamba and chlorsulfuron inhibited fungal growth on potato dextrose agar (PDA) at concentrations 10–500-fold of rates recommended for use in the field. The vegetative growth of the pathogen growing out of straw colonized on PDA supplemented with 100 ppm diquat + paraquat or glyphosate was reduced by 47.4% and 42.4%, respectively. When portions of these colonies were subcultured onto unamended PDA, their growth and the pathogenicity of straw pieces colonized by these subcultures were found to be unaltered. Straw colonized by Ggt on agar amended with concentrations of diquat + paraquat or at all concentrations of glyphosate produced less root disease in wheat seedlings in comparison to those colonized on unamended agar. It is proposed that the reduced pathogenicity of inocula prepared on agar amended with these two herbicides is due to poor colonization by the pathogen of straw on these media, and that a similar effect on saprophytic colonization in the field could lead to a reduction in the field inocula of the pathogen.     

不同基因型玉米对草丁膦、绿黄隆抗性试验

以不同基因型的玉米为材料,在三叶期分别喷洒5个浓度的除草剂草丁膦和绿黄隆,观察不同基因型玉米的生长状况和受到药害后的特征变化,为抗除草剂转基因玉米的筛选提供一定的参考。结果如下:对绿黄隆抗性最强的为自交系连玉87,最弱的为昌7-2;对草丁膦抗性最强的为9801,最弱的为郑58。喷除草剂后3 d和6 d时,通过测量连玉87和昌7-2中可溶性糖、游离氨基酸和氨基酸总量,发现在喷洒草丁膦或绿黄隆后,植株体内可溶性糖总量增加。草丁瞵处理后3 d和6 d时,氨在体内的含量分别增加了3.25倍和7倍,氨基酸总量在3 d时减少了56.31%,6 d时增加了15.11%。绿黄隆喷洒后3 d时,氨基酸总量减少了34.00%;6 d时,氨基酸总量减少了65.03%。     

Effect of certain herbicides on soil microbial populations and their influence on saprophytic growth in soil and pathogenicity of take-all fungus

Summary The application of diquat + paraquat, glyphosate and trifluralin to unsterilized field soil increased take-all caused by the fungus, Gaeumannomyces graminis var. tritici Walker by 13.0% 16.6% and 10.8% respectively, while no effect on disease was recorded in sterilized soil treated with the same herbicides. The herbicides tested had no effect on the saprophytic growth of the pathogen with the exception of glyphosate, which increased its growth in unsterilized soil. The application of diquat + paraquat and glyphosate to unsterile soil had no effect on the numbers of actinomycetes. The diquat + paraquat treatment, however, increased populations of fungi while the glyphosate decreased the numbers of bacteria. The proportion of soil fungi antagonistic to the pathogen was reduced in glyphosate-treated soil. The frequency of occurrence of Eupenicillium euglaucum (v. Beyma) Stolk & Samson (strain B), and Penicillium verruculosum Peyr. (strain B), which were strong and low level antagonists of Ggt on agar, were reduced in their occurrence in soil by 7.7% and 2.5% respectively, following glyphosate treatment. Moreover, the numbers of Aspergillus viridinutans Ducker & Thrower, which showed moderate antagonism to the pathogen, was decreased by 1.9% and 4.1% in diquat + paraquat and glyphosate treatments respectively. The proportion of antagonists rather than total numbers of fungi appears to be related to the treatment effect observed on the soil growth and pathogenicity of G. graminis var. tritici in our investigation. The increase in disease of wheat in certain herbicide-treated soils may be due to the shift in soil microbial populations away from those which are antagonistic to the pathogen.     

除草剂解毒剂对玉米绿磺隆残留药害的解毒效果初报

采用室内盆栽和小区试验等生物测定方法,通过对玉米株高、株鲜重、单株产量、果实中支链氨基酸等指标的测定,研究了除草剂解毒剂3-二氯乙酰基-2,5-二甲基-2-乙基-1,3-噁唑烷减轻除草剂绿磺隆对玉米等后茬敏感作物伤害的生物活性。实验结果表明：上一年使用过绿磺隆的地块,下一年播种玉米时,可以通过3-二氯乙酰基-2,5-二甲基-2-乙基-1,3-噁唑烷的浸种、拌种、混喷、叶喷来减轻药害,其中混喷方法效果最好,为对照的99.41%,浸种方法仅次于混喷,为对照的95.65%。应用除草剂解毒剂使绿磺隆的残留量小于5μg/kg时,后茬可以种植玉米。     

除草剂安全剂3-二氯乙酰基-2-甲基-2-乙基-1，3-噁唑烷对绿磺隆解毒效果研究

主要采用室内生物测定的方法,通过对玉米生理指标—根长、根鲜重的测定,研究了除草剂安全剂3-二氯乙酰基-2-甲基-2-乙基-1,3-噁唑烷保护玉米免受除草剂绿磺隆在不同浓度时的伤害。结果表明：当安全剂与绿磺隆按一定浓度配比混合,对玉米有较好的保护效果,保护率可达60%~170%。     

Activity of Acetolactate Synthase from Maize (Zea mays L. ) as Influenced by Chlorsulfuron and Tribenuron-methyl

Study on relative sensitivity of maize (Zea mays L. ) Nongda108 and Nongda3138 to sulfonylurea herbicide chlorsulfuron and tribenuron-methyl using maize taproot length by sand bioassy indicated that, Nongda3138 had higher tolerance to chlorsulfuron and tribenuron-methyl than Nongda108 did. Chlorsulfuron had stronger growth inhibition to maize Nongda108 and Nongda3138 than tribenuron-methyl did. Study on target enzyme of sulfonylurea herbicide acetolactate synthase (ALS) showed that, chlorsulfuron and tribenuron-methyl inhibited ALS in vitro strongly, and non-competitively. In the same concentration of inhibitors,chlorsuifuron had stronger ALS activity inhibition than tribenuron-methyl did. Lower level of chlorsulfuron and tribenuron-methyl has no ALS activity inhibition in vivo, the ALS inhibition only occurred in the condition of high concentration of chlorsulfuron and tribenuron-methyl in vivo.     

麦谷宁生测方法及其对玉米的安全性研究

选用种植面积较大且抗逆性较强的玉米品种农大 108为指示植物 ,研究了麦谷宁的玉米沙培试验方法。结果表明 ,浸种催芽 ,播种后先盖覆沙量的一半后加药 60mL,再盖沙至 2 cm厚 ,于 2 5℃黑暗培养 3d,可获得满意的结果。回归分析表明 ,麦谷宁浓度的对数与玉米主根长抑制率相对应的机率值成很好的线性关系 ,r2 均大于 0 .90。就大面积种植的 16个玉米品种对麦谷宁的敏感性测定结果表明 ,掖单 12对麦谷宁较敏感 ,农大 3138对麦谷宁耐药力最强 ,各品种对麦谷宁的 IC50 值均大于 7.38μ g· kg-1,感性介于烟嘧磺隆和氯磺隆之间