尿素增强烯草酮胁迫下紫苏幼苗耐性的研究

为探讨烯草酮与尿素处理对紫苏生长的影响,阐明尿素对紫苏在烯草酮胁迫下耐性的调节效应。采用随机区组试验设计,在紫苏六叶期喷施不同浓度的尿素（0、1、2、4和 8 g/L）和24%烯草酮乳油（0、0.67、1.33、2.66和 3.99 mL/L）,分析其对紫苏生长、光合特性、抗逆性指标、杂草防效和产量的影响。结果表明,烯草酮抑制紫苏幼苗生长,降低光合特性,使丙二醛积累增加,超氧化物歧化酶、过氧化物酶活性随其浓度的增加呈先上升后下降趋势;而1～4 g/L浓度的尿素处理则促进生长,并提高了光合特性;8 g/L的尿素处理效果相反。1～4 g/L的尿素和不同浓度的烯草酮先后处理,比单施烯草酮处理的效果好,A组（先喷施尿素后喷施烯草酮）的C1N3（4 g/L尿素,0.67 ml/L烯草酮）处理可使现蕾期产量和子粒产量比单独施用烯草酮增产13.94 %和10.54 %,株防效提高11%。表明在紫苏六叶期先喷施4 g/L的尿素再喷施0.67 mL/L 的烯草酮,能显著提高紫苏幼苗在烯草酮胁迫下的耐性,提高幼苗净光合速率,促进植株生长,这些效应与其提高抗氧化酶活性有关;该施药模式具有提高防效,安全高产等特点,有较高的推广价值。     

Mechanisms of resistance to acetyl-coenzyme A carboxylase inhibitors: a review

Resistance to acetyl-coenzyme A carboxylase (ACCase) inhibitors has developed in at least 10 grass weed species in recent years. In most instances, resistance is conferred by an ACCase alteration in the resistant biotypes that reduces sensitivity to aryloxyphenoxypropionate (AOPP) and cyclohexanedione (CHD) herbicides. Analysis of ACCase from many of these resistant weed biotypes suggests the presence of different mutations, each conferring a different pattern and level of resistance to various AOPP and CHD herbicides. In all cases analyzed to date, resistance is controlled by a single dominant or semi-dominant nuclear gene. In several weed biotypes, resistance is conferred by enhanced herbicide detoxification, primarily through elevated expression or activity of cytochrome P450 monooxygenase(s). This mechanism can confer cross-resistance to herbicides from other chemical classes with different modes of action. Finally, multiple herbicide resistance, i.e. the acquisition of several different resistance mechanisms, has been reported in some weed biotypes. ©1997 SCI     

24%烯草酮乳油防除甜菜田禾本科杂草效果

通过对不同浓度24%的烯草酮乳油在甜菜上的应用,用精稳杀得做对照,来试验烯草酮乳油在甜菜上的效果,以选择出适合甜菜生产所适用的除草剂及浓度。结果表明,不同浓度的烯草酮乳油防治甜菜杂草效果显著。     

240克/升烯草酮乳油防除夏大豆田杂草田间药效试验

田间试验结果表明,夏大豆田播后苗期使用240克/升烯草酮乳油30～40克/667m2,对禾本科杂草有较好的防除效果,并且有较长的持效期,对大豆生长安全。     

Bermudagrass (Cynodon spp) dose-response relationships with clethodim, glufosinate and glyphosate

Greenhouse studies were conducted to evaluate the sensitivity of three commercial cultivars, eight experimental cultivars and common bermudagrass to clethodim, glufosinate and glyphosate. Each herbicide was applied at eight doses. Data were regressed on herbicide dose using a log-logistic curve (R2 = 0.56-0.95 for clethodim, R2 = 0.60-0.94 for glufosinate, and R2 = 0.70-0.96 for glyphosate). The herbicide rate that elicited a 50% plant response (I50) in the bermudagrass cultivars ranged from 0.04 to 0.19 kg ha(-1) clethodim, 0.19 to 1.33 kg ha(-1) glufosinate and 0.34 to 1.14 kg ha(-1) glyphosate. Relative to other cultivars, common bermudagrass was intermediate in its response to clethodim and among the most tolerant cultivars to glufosinate and glyphosate. TifSport was relatively tolerant to clethodim and glufosinate compared with other cultivars, but relatively sensitive to glyphosate. One cultivar, 94-437, was consistently among the most sensitive cultivars to each of the herbicides. While there were differential herbicide tolerances among the tested bermudagrass cultivars, there did not appear to be any naturally occurring herbicide resistance that could be commercially utilized. However, research indicated that breeding efforts should target herbicide resistance that is at least four times the registered use rate. Also, TifSport and Tifway have been identified as suitable representatives of triploid hybrid bermudagrass cultivars to be used to evaluate the success of turfgrass renovation programs.     

影响烯草酮降解因素的研究

本文介绍了影响烯草酮降解的一些因素，明确了微生物，腐殖酸和单线态氧对土壤中烯草酮在降解影响，即施药后７２ｈ烯草酮在微生物，腐殖酸和单线态氧作用下，相对降解率分别为３１％５２．６１％和１８．１５％，而水溶性中的烯草酮在光和腐殖酸的作用下，不产生降解。     

油菜田看麦娘对精喹禾灵抗性监测及与烯草酮交互抗性

通过对看麦娘抗药性水平的检测以及抗性机理的研究,以期为油菜田看麦娘的抗性治理和科学合理用药提供理论依据。采用整株法测定了长江中下游地区的4个省13个市17个地区的油菜田看麦娘生物型对精喹禾灵的抗性水平及与烯草酮的交互抗性,分别测定了精喹禾灵与烯草酮对抗性看麦娘(R-TY)、敏感看麦娘(S-NJ)体内GSTS活性。抗精喹禾灵监测结果显示:TY生物型相对抗性倍数最高,为28.92,GR50为90.183。其次为YZ生物型和BLD生物型,GR50分别为34.480和45.472,相对抗性倍数分别为11.06和14.58。其余生物型相对抗性倍数在1.62~9.16之间。与烯草酮的交互抗性结果显示:对精喹禾灵产生抗性的TY、BLD生物型对烯草酮也产生了抗性,存在交互抗性,而对精喹禾灵敏感的DYX生物型看麦娘却对烯草酮产生了抗性,说明看麦娘生物型中存在不同的抗性模式。GSTS活性测定结果显示:经药剂处理后,R-TY生物型GSTS活性始终比敏感生物型S-NJ高,表明TY生物型产生抗性的原因可能是GSTS对药剂的代谢作用增强。     

快速溶剂萃取高效液相色谱法测定土壤中 乙草胺和烯草酮残留

建立一种从土壤中快速溶剂萃取乙草胺和烯草酮结合高效液相色谱法测定其残留量的方法。用甲醇-水(体积比为40:60)作为提取剂快速萃取土壤中的乙草胺和烯草酮,采用高效液相色谱法进行乙草胺和烯草酮残留量测定。使用Dionex C18色谱柱,甲醇-水(体积比为70:30)为流动相,流速为1.0 mL·min~(-1),使用紫外检测器,检测波长为215 nm。结果显示,乙草胺和烯草酮保留时间分别为5.82和3.75 min,线性相关系数为0.9980及0.9969。在5个质量分数添加水平范围内,回收率分别在91.00%~98.16%和90.20%~95.62%之间,相对标准偏差(RSD)分别在1.98%~7.05%和2.73%~6.14%之间,方法检出限分别为0.020和0.013μg·L~(-1),定量限(LOQ)分别是0.050和0.040μg·kg~(-1)。该方法操作步骤简单快速、准确度好,能够适用于土壤中乙草胺和烯草酮残留的快速检测。     

240g·L~(-1)烯草酮乳油防除洋葱田禾本科杂草研究

为探讨烯草酮EC对禾本科杂草的防治效果,以洋葱品种红一号为试材,研究了240g·L~(-1)烯草酮EC加入3种专用助剂不同处理对禾本科杂草的防效。结果表明:240g·L~(-1)烯草酮EC180、240、300、600mL·hm-2+0.125%Amigo专用助剂各处理,对洋葱田禾本科杂草防效达89.7%~100%,240g·L~(-1)烯草酮EC16mL·hm-2+0.2%TM-4专用助剂处理,对洋葱田禾本科杂草防效达87.0%~99.5%,240g·L~(-1)烯草酮EC240mL·hm-2+0.05%力透专用助剂对禾本科杂草的株数没有防效,鲜重防效只有72.5%和78.7%。各处理均有一定的增产效果。推荐使用的最佳应用剂量范围为240g·L~(-1)烯草酮EC240~300mL·hm-2+0.125%Amigo专用助剂和240g·L~(-1)烯草酮EC240mL·hm-2+0.2%TM-4专用助剂。施药适期为移栽后洋葱苗4~5叶;稗草、野黍等禾本科杂草3~5叶期,施药方法为洋葱苗后茎叶喷雾。