外来入侵杂草宽叶酢浆草的研究进展

宽叶酢浆草(Oxalis latifolia)在全球分布广泛,且危害多种农作物,2007年中国将其列入进境植物检疫性有害生物名录.目前,在中国仅发生于云南省,但其适生性强,定殖和传播扩散的风险极高.本文就宽叶酢浆草的生物学特性、发生分布和危害以及防控措施等相关研究进行综述,为制定有效的防控措施提供参考.     

杂草对激素类除草剂抗药性研究进展

农田杂草严重影响作物的产量和品质,对除草剂的过度依赖和长期使用,使杂草对除草剂的抗性问题日益突出。目前已有262种杂草(152种双子叶和110种单子叶)的512个生物型对23类中的167个除草剂产生抗性。激素类除草剂作为除草剂的重要成员,为禾谷类作物田的杂草防除提供了保障,然而在使用了几十年后,44种杂草对此类除草剂产生了抗药性。本文对激素类除草剂的分类应用、除草机理、抗性现状、抗性机理等进行了综述,以期为激素类除草剂的应用和抗激素类除草剂杂草的防除提供参考。     

外来入侵植物假臭草的研究进展

假臭草是我国南方重要外来入侵杂草之一,目前已对农林牧业和生物多样性造成危害,并有向北扩散蔓延的趋势。本文对其生物学特性、生态学特征、危害性、化感作用、防除措施等方面的研究进行了综述,并提出今后的研究设想。     

细胞色素P450介导的杂草抗药性研究进展

细胞色素P450(cytochrome P450)是一类重要的亚铁血红素-硫醇盐蛋白超家族, 属于单加氧酶, 广泛分布于生物界中。研究发现P450主要具有“生物合成”和“生物解毒”两大功能, 被誉为“万能的生物催化剂”。大多数除草剂在植物体内代谢的初始阶段即涉及植物细胞色素P450的作用。近些年, 由P450介导的抗药性杂草呈多发态势, 其复杂的抗性谱, 给杂草化学防除带来了新的挑战。本文对P450分类命名、P450与除草剂代谢的关系、P450抗性鉴定手段、P450介导抗性杂草发生情况、与除草剂代谢有关的植物细胞色素P450基因克隆等内容进行了综述, 旨在为该领域的相关研究提供参考。     

外来入侵植物加拿大一枝黄花的研究进展

外来生物的入侵给我国的生态平衡造成了严重影响,导致了不可估量的经济损失。本文对外来入侵植物加拿大一枝黄花的分布、生物学及生态学特性、化感作用及机理等方面进行了综述。     

琥珀酸脱氢酶抑制剂类杀菌剂水生生态毒理学研究进展

作为当前杀菌剂市场的主要种类之一,琥珀酸脱氢酶抑制剂类(SDHIs)杀菌剂的广泛应用导致其易进入水体环境,威胁水生生物的安全.大量研究表明,该类药剂中大部分品种对水生生物的急性毒性较高,部分甚至达到剧毒级,并且在较低浓度下即可对水生生物产生毒性效应,不同程度影响水生生物的生长、发育和繁殖,进而导致水生生态系统的失衡.文...     

A review of aquatic weed biology and management research conducted by the United States Department of Agriculture-Agricultural Research Service

Ever-increasing demand for water to irrigate crops, support aquaculture, provide domestic water needs and to protect natural aquatic and riparian habitats has necessitated research to reduce impacts from a parallel increase in invasive aquatic weeds. This paper reviews the past 4-5 years of research by USDA-ARS covering such areas as weed biology, ecology, physiology and management strategies, including herbicides, biological control and potential for use of natural products. Research approaches range from field-level studies to highly specific molecular and biochemical work, spanning several disciplines and encompassing the most problematic weeds in these systems. This research has led to new insights into plant competition, host-specificity, and the fate of aquatic herbicides, their modes of action and effects on the environment. Another hallmark of USDA-ARS research has been its many collaborations with other federal, state action and regulatory agencies and private industry to develop new solutions to aquatic weed problems that affect our public natural resources and commercial enterprises.     

Herbicides used in combination can reduce the probability of herbicide resistance in finite weed populations

A simulation study was conducted to examine the effect of pattern of herbicide use on development of resistance to two herbicides with different modes of action in finite weed populations. The effects of the size of the treatment area (analogous to initial weed population), germination fraction and degree of self‐pollination in the weed were investigated. The results indicate that the probability of developing resistance to one or both herbicides decreases as the size of the area/initial population decreases. For treatment areas of 100 ha or less with an initial weed seedbank of 100 seeds m^?2 and initial frequencies of the resistance genes of 10^?6, development of resistance to both herbicides (double‐resistance) is uncommon within 50 years for all types of weeds if both herbicides are used in all years (used in combination). If herbicides are used in alternate years (rotated) double‐resistance almost always occurs in 100 ha areas but is uncommon in areas of 1 ha or less. The results suggest that adoption of practices that limit movement of weeds in conjunction with using herbicides in combination rather than in rotation can substantially delay development of herbicide resistance.     

磺酰脲类除草剂与杂草对其抗性的研究进展

1磺酰脲类除草剂的概况1.1磺酰脲类除草剂的发展20世纪70年代末,美国杜邦公司Levitt等首次开发和报道了磺酰脲类除草剂绿磺隆的除草活性[1]。80年代初,这一除草剂开始进行大规模商品化生产,此后,又不断研制和开发了许多磺酰脲类除草剂新品种。此类除草剂问世以后,以其活性高、选择性强、杀草谱广及对动物安全等特性在世界各地得到广泛应用。目前有关磺酰脲类除草剂的专利有400多项,已商品化的有30多种。这类除草剂有很高的除草效率,用量一般为2~100 g/hm2,比传统除草剂的除草效率高100~1 000倍[2]。磺酰脲类除草剂对动物低毒,在非靶标生物…     

Evaluation of models used to assess the fate of chemicals in aquatic systems

Five reference chemicals, 2,5,4′-trichlorobiphenyl (3-CB), chloroform, parathionmethyl (MEP), pentachlorophenol (PCP) and 3,4-dichloroaniline (DCA), were applied to experimental outdoor ponds by sub-surface injection. Samples of water, sediment and vegetation were removed and analysed for residues at various intervals after treatment. The fate of these chemicals in the ponds was predicted through the use of process analyses and mathematical models. The predicted rates of loss were compared with experimental observations. Data obtained for 3-CB were fitted to a three-compartment model and this was used to calculate the rates of transport between water and sediment, and between water and vegetation. These processes are primarily dependent on turbulent mixing. In experiments with MEP it was shown that biodegradation was primarily associated with bacterial populations in the sediment rather than with those suspended in the water. The rate of biodegradation in sediment was relatively fast and there was no detectable lag phase. The sediment could therefore be considered a sink for MEP and the overall rate of loss of the latter was dependent on its rate of transport to the sediment. In an experiment with chloroform there was reasonably good agreement between predicted and observed rates of evaporation. However, observed rates were always greater than predicted rates, suggesting a systematic bias that may warrant further investigation. In experiments with PCP and DCA there was good agreement between predicted and observed rates of phototransformation.