21% 乙羧·草铵膦微乳剂的研制与应用

【目的】研制高效广谱除草剂21%乙羧·草铵膦微乳剂配方,对其理化性能进行检测,并将其用于防除非耕地杂草。【方法】采用优化组合法对不同表面活性剂进行筛选试验,确定21%乙羧·草铵膦微乳剂最优配方。通过田间药效试验研究21%乙羧·草铵膦微乳剂对非耕地杂草的防除效果。【结果】最优配方(质量分数)为:20%(折百)草铵膦,1%乙羧氟草醚,7%环已酮,10%正丁醇,20%乳化剂(OA-TAPO∶烷基糖苷∶甜菜碱=3∶2∶1),水补足100%。田间试验结果表明,21%乙羧·草铵膦微乳剂270～540 mL/hm~2对非耕地杂草有明显的防除效果,茎叶喷雾药后5 d对禾本科杂草、阔叶杂草的覆盖度防效可达80.41%～83.47%、84.44%～88.13%,药后10 d对禾本科杂草、阔叶杂草的覆盖度防效可达92.69%～94.55%、95.61%～96.72%,药后30 d对禾本科杂草、阔叶杂草的覆盖度防效可达93.64%～96.04%、97.59%～98.45%,鲜质量防效可达93.65%～96.09%、97.37%～98.51%。【结论】草铵膦与乙羧氟草醚复配可拓宽除草谱;21%乙羧·草铵膦微乳剂可以有效防除非耕地杂草,速效性与持效性优于市售20%草铵膦可溶液剂、10%乙羧氟草醚乳油。     

Agronomic performance of F1, F2 and F3 hybrids between weedy rice and transgenic glufosinate-resistant rice

BACKGROUND: Studies of hybrid fitness, of which agronomic performance may be an indicator, can help in evaluating the potential for introgression of a transgene from a transgenic crop to wild relatives. The objective of this study was to assess the agronomic performance of reciprocal hybrids between two transgenic glufosinate‐resistant rice lines, Y0003 and 99‐t, and two weedy rice accessions, WR1 and WR2, in the greenhouse. RESULTS: F₁ hybrids displayed heterosis in height, flag leaf area and number of spikelets per panicle. The agronomic performance of F1 between WR1 and Y0003 was not affected by crossing direction. The tiller and panicle numbers of F1 individuals were higher than their F2 counterparts. However, these traits did not change significantly from the F2 to the F3 generation or in hybrids with weedy rice as maternal or paternal plants. For all hybrids, the in vitro germination rates of fresh pollen were similar and significantly lower than those of their parents, seed sets were similar to or of lower value than those of weedy rice parents and seed shattering characteristics were partially suppressed, but the survival of hybrids over winter in the field was similar to that of weedy rice parents. All F1, F2 and F3 hybrids had similar composite agronomic performance to weedy rice parents. CONCLUSION: There was no significant decrease in the composite agronomic performance of any of the hybrids compared with weedy rice. This implies that gene flow from transgenic cultivated rice to weedy rice could occur under natural conditions. Copyright © 2011 Society of Chemical Industry     

不同除草剂对转Bar基因马铃薯田间杂草的防效及安全性分析

为了安全防除抗草铵膦转基因马铃薯田间杂草,以转Bar基因马铃薯为试验材料,分析比较了有效成分1 440 g·hm^-2灭草松(T1)、99 g·hm^-2 11%砜嘧磺隆·精喹禾灵(T2)、1 440 g·hm^-2灭草松+ 99 g·hm^-2 11%砜嘧磺隆·精喹禾灵复配剂(T3)、1 695 g·hm^-2草铵膦(T4)、923 g·hm^-2草甘膦(T5)和清水(CK)处理下杂草防效、马铃薯生长指标、块茎产量及品质特性和药剂残留情况。结果表明,草甘膦在杀灭杂草的同时,也杀死了马铃薯植株,受害率达100%;灭草松、11%砜嘧磺隆·精喹禾灵和草铵膦对马铃薯均未产生药害,但因对杂草的防效不同而导致达到的增产效果差异显著。药后45 d时,灭草松和11%砜嘧磺隆·精喹禾灵复配剂(T3)对阔叶杂草的株、鲜重防效较灭草松单独处理(T1)分别提高35.13和38.71个百分点,较11%砜嘧磺隆·精喹禾灵单独处理(T2)分别提高23.88和16.29个百分点,对禾本科杂草的株、鲜重防效较T1分别提高78.36和80.92个百分点,较T2分别提高11.85和8.23个百分点,马铃薯单株产量较CK、T1和T2分别增加58.39%、35.52%和11.44%。草铵膦(T4)对阔叶和禾本科杂草的株、鲜重防效都显著高于T1、T2和T3,单株产量较CK、T1、T2和T3分别增加67.40%、43.24%、17.79%和5.6%。因此,用有效成分1 695 g·hm^-2的草铵膦可以高效防治转Bar基因马铃薯田间杂草,但为了防止转Bar基因马铃薯连作时,因靶标除草剂草铵膦作用单一而诱导杂草产生草铵膦抗性的风险,建议用有效成分 1 440 g·hm^-2 的灭草松和99 g·hm^-2 11%砜嘧磺隆·精喹禾灵复配剂与草铵膦轮换防治杂草。本研究为转Bar基因马铃薯大面积种植中田间杂草的科学防治提供了科学依据。     

The Build-up of the Present Desert Locust Plague

Abstract

Imperata cylindrica is one of the most noxious weeds in South East Asia. Over the past two decades significant advances have been made in the understanding of its biology and control. This paper reviews work over this period and concludes that despite such advances, there remains much scope for improvement of control, particularly in development of methods appropriate for small scale farmers with limited resources.     

Weed control in conventional and herbicide tolerant winter oilseed rape (Brassica napus) grown in rotations with winter cereals in the UK

Two winter oilseed rape (Brassica napus) cultivars, tolerant to glyphosate and glufosinate, were compared with a conventional cultivar at three sites over 4 years, in 3‐year crop rotations in the UK. The winter oilseed rape was grown in Years 1 and 4, with winter cereals, which received uniform herbicide treatments, in the intervening years. The second winter oilseed rape treatments were applied to randomised sub‐plots of the original plots. Weed densities were recorded in autumn and spring and weed biomass was measured in summer. At most sites, there was only one application of glufosinate or glyphosate, whereas two products were often used on the conventional variety. The timing of glyphosate and glufosinate application was, on average, 34 days later than that of the conventional broad‐leaved weed control treatments. Overall weed control, across all sites and years, was not statistically different between the conventional, glyphosate and glufosinate treatments. However, glyphosate achieved higher control of individual weed species more frequently than the other treatments. Glufosinate and the conventional treatments were similar in performance. The treatments in Year 1 sometimes affected weed populations in the subsequent cereal crops and, in rare instances, those in the rape in Year 4. Carry‐over effects were small after most treatments. In general, weed survival was greater in the oilseed rape crops, irrespective of the treatment, than it was in the intervening cereal crops.     

草铵膦胁迫下油菜苗期叶片药害相关性状的全基因组关联分析

随着油菜大面积种植和田间草害的日益严重, 草铵膦近年来被尝试性地用于田间除草, 但草铵膦在杀除杂草的同时或轻或重会对油菜产生药害, 影响其正常生理活动, 甚至影响其产量。本研究通过比较, 选取最能体现油菜苗期耐药性差异的200 mg L^-1作为胁迫浓度。以506份具有代表性的甘蓝型油菜品种(系)为材料, 利用芸薹属60k Illumina Infinium SNP芯片分析其基因型, 对油菜种质苗期的单位叶面积干重耐除草剂系数(CLW)、叶绿素含量耐除草剂系数(CCC)和综合药害指数(CPC)进行全基因组关联分析, 从基因组水平分析油菜在草铵膦胁迫下的生理和形态反应。关联分析中, 扫描到与单位叶面积干重耐除草剂系数显著相关的SNP位点6个, 表型贡献率在6.53%~10.04%之间; 与叶绿素含量耐除草剂系数相关的SNP位点共22个, 表型贡献率在4.97%~6.20%之间; 与综合药害指数相关的SNP位点98个, 覆盖了A、C基因组, 贡献率在3.25%~18.66%之间。通过对显著SNP位点对应的LD区间基因序列的分析, 共获得18个与草铵膦的灭生机制相关的候选基因。在叶绿素含量耐除草剂系数关联位点的LD区域发现11个候选基因, 其中9个参与酰基转移酶活性的调控, 2个与乙酰CoA转移酶活性有关。在与综合药害指数关联位点的LD区域发现7个候选基因, 其中1个与谷氨酰胺转移酶活性有关, 参与谷氨酰胺代谢, 其余6个和乙酰CoA转移酶活性有关。这些基因调控的生理生化过程均与叶片干重、叶绿素含量的变化及草铵膦的灭生机制有关。这些关联位点和候选基因的挖掘, 将为油菜在草铵膦逆境胁迫下的生理生态反应的基因调控机制研究提供参考。     

草铵膦在杂交狗牙根交播黑麦草草坪建植中的应用研究

研究了不同剂量草铵膦对杂交狗牙根(Cynodon dactylon)交播多年生黑麦草(Lolium perenne)草坪的质量调控效果。结果表明:低剂量草铵膦处理(225,450 g/hm2)对杂交狗牙根草坪的色泽没有显著的影响,但能够显著抑制杂交狗牙根的生长,而中、高剂量处理则对杂交狗牙根草坪的色泽有显著的负面影响;所有草铵膦处理对多年生黑麦草的萌发没有影响,且能够显著改善交播草坪的冬季色泽,450g/hm2剂量处理的冬季色泽均能维持在90%;低剂量草铵膦处理(225,450 g/hm2)对杂交狗牙根草坪的春季返青没有显著的影响,但中、高剂量的草铵膦处理则对杂交狗牙根的春季返青造成了严重的负面影响,显著延迟了杂交狗牙根的春季返青进程。试验表明450 g/hm2的草铵膦处理是交播草坪最适宜的应用剂量。     

Perspectives on transgenic,herbicide‐resistant crops in the United States almost 20 years after introduction

Herbicide‐resistant crops have had a profound impact on weed management. Most of the impact has been by glyphosate‐resistant maize, cotton, soybean and canola. Significant economic savings, yield increases and more efficacious and simplified weed management have resulted in widespread adoption of the technology. Initially, glyphosate‐resistant crops enabled significantly reduced tillage and reduced the environmental impact of weed management. Continuous use of glyphosate with glyphosate‐resistant crops over broad areas facilitated the evolution of glyphosate‐resistant weeds, which have resulted in increases in the use of tillage and other herbicides with glyphosate, reducing some of the initial environmental benefits of glyphosate‐resistant crops. Transgenic crops with resistance to auxinic herbicides, as well as to herbicides that inhibit acetolactate synthase, acetyl‐CoA carboxylase and hydroxyphenylpyruvate dioxygenase, stacked with glyphosate and/or glufosinate resistance, will become available in the next few years. These technologies will provide additional weed management options for farmers, but will not have all of the positive effects (reduced cost, simplified weed management, lowered environmental impact and reduced tillage) that glyphosate‐resistant crops had initially. In the more distant future, other herbicide‐resistant crops (including non‐transgenic ones), herbicides with new modes of action and technologies that are currently in their infancy (e.g. bioherbicides, sprayable herbicidal RNAi and/or robotic weeding) may affect the role of transgenic, herbicide‐resistant crops in weed management. Published 2014. This article is a U.S. Government work and is in the public domain in the USA.     

Initial report of glufosinate and paraquat multiple resistance that evolved in a biotype of goosegrass (Eleusine indica) in Malaysia

Field and glasshouse studies have confirmed the presence of a glufosinate‐ and paraquat‐resistant goosegrass biotype that has infested a bitter gourd field in Air Kuning, Perak, Malaysia. Glufosinate and paraquat had been applied at least six times per year to the affected fields (originally a rubber plantation) for more than four consecutive years. Paraquat had been used since 1970 for weed control in the rubber plantation. An on‐site field trial revealed that the control of the goosegrass plants, measuring 20–35 cm in height, ranged from 20 to 35% 3 weeks after being treated with each herbicide at twice the recommended rate. Dose–response tests were conducted in the glasshouse, using seedlings at the three‐to‐four‐leaf stage that had been obtained from the plants that had received repeated exposure to these herbicides and a biotype with no history of any herbicide resistance. The comparison of the GR₅₀ (the herbicide rate that is required to reduce the shoot fresh weight by 50%) of the seedlings indicated that the resistant biotype of goosegrass is 3.4‐fold and 3.6‐fold more resistant than the susceptible biotype following treatment with glufosinate and paraquat, respectively. This study has demonstrated the world's first field‐evolved instance of multiple resistance in goosegrass to two non‐selective herbicides, glufosinate and paraquat.