Changes in the herbicide sensitivity and competitive ability of Abutilon theophrasti over 28 years: Implications for hormesis and weed evolution     

Sandra R. Ethridge  Saket Chandra  Anna M. Locke  Wesley J. Everman  David L. Jordan  Micheal D.K. Owen  Ramon G. Leon 《Pest management science》2023,79(10):4048-4056

BACKGROUND

The potential of weed species to respond to selection forces affecting the evolution of weedy traits such as competitive ability is poorly understood. This research characterized evolutionary growth changes in a single Abutilon theophrasti Medik. population comparing multiple generations collected from 1988 to 2016. A competition study was performed to understand changes in competitive ability, and a herbicide dose–response study was carried out to assess changes in sensitivity to acetolactate synthase-inhibiting herbicides and glyphosate over time.

RESULTS

When grown in monoculture, A. theophrasti biomass production per plant increased steadily across year-lines while leaf number decreased. In replacement experiments, A. theophrasti plants from newer year-lines were more competitive and produced more biomass and leaf area than the oldest year-line. No clear differences in sensitivity to imazamox were observed among year-lines. However, starting in 1995, this A. theophrasti population exhibited a progressive increase in growth in response to a sublethal dose of glyphosate (52 g a.e. ha⁻¹), with the 2009 and 2016 year-lines having more than 50% higher biomass than the nontreated control.

CONCLUSION

This study demonstrates that weeds can rapidly evolve increased competitive ability. Furthermore, the results indicate the possibility of changes in glyphosate hormesis over time. These results highlight the importance of the role that rapid (i.e., subdecadal) evolution of growth traits might have on the sustainability of weed management strategies. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

Ace and ace-like genes of invasive redlegged earth mite: copy number variation,target-site mutations,and their associations with organophosphate insensitivity     

Joshua A. Thia  Paul A. Umina  Ary A. Hoffmann 《Pest management science》2023,79(11):4219-4230

Background

Invasive Australian populations of redlegged earth mite, Halotydeus destructor (Tucker), are evolving increasing organophosphate resistance. In addition to the canonical ace gene, the target gene of organophosphates, the H. destructor genome contains many radiated ace-like genes that vary in copy number and amino acid sequence. In this work, we characterise copy number and target-site mutation variation at the canonical ace and ace-like genes and test for potential associations with organophosphate insensitivity. This was achieved through comparisons of whole-genome pool-seq data from alive and dead mites following organophosphate exposure.

Results

A combination of increased copy number and target-site mutations at the canonical ace was associated with organophosphate insensitivity in H. destructor. Resistant populations were segregating for G119S, A201S, F331Y at the canonical ace. A subset of populations also had copy numbers of canonical ace > 2, which potentially helps overexpress proteins carrying these target-site mutations. Haplotypes possessing different copy numbers and target-site mutations of the canonical ace gene may be under selection across H. destructor populations. We also detected some evidence that increases in copy number of radiated ace-like genes are associated with organophosphate insensitivity, which might suggest potential roles in sequestration or breakdown of organophosphates.

Conclusion

Different combinations of target-site mutations and (or) copy number variation in the canonical ace and ace-like genes may provide non-convergent ways for H. destructor to respond to organophosphate selection. However, these changes may only play a partial role in organophosphate insensitivity, which appears to have a polygenic architecture. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

On the Development of Urban Spatial Structure in the Information Age     

LI He-ping  YAN Ai-qiong 《保鲜与加工》2002,(4):1-6

Today the information globalization is the trend of society development. The information technology has great influence not only on the mode of life and production, but also on the urban social and economic structure. In order to fit in with the change in this regard, the urban land-use distribution, residential mode, traffic pattern and so on should be changed correspondingly. Therefore, this change will lead to the development and evolution of whole urban spatial structure. In this paper, the development tendency of urban spatial structure in the information age is analyzed and some proposals on city planning and construction are put forward.  相似文献   

On System Stability under Random Perturbations     

Huang Wei 《保鲜与加工》1995,(4):81-85

In this paper we concider the problem of stability of stochastic evolution systemsin Hilbert space drived by a cylindrical Brownian mothin. We regard the stochestic evolutionequation dXt = AXtdt +G(Xt)dBt as a deterministic system of the form dXt=AXtdt under randomperturbation,and obtain stability of its solution. It is shown that under certain assumptions,itsevolution solution and L2-contimuous evulution solution are exponertially stable.  相似文献   

Study on Bed Evolution of Fuling Reach in Three Gorges Reservoir District     

《保鲜与加工》2003,(1):73-76117

  相似文献   

Asymptotic Attractors of the Nonlinear Evolution Equation in Bounded Domain     

ZHAO Lei-n  ZHANG Xing-you  XING Ting-li 《保鲜与加工》2007,(2):136-138148

The basic principle of infinite-dimensional dynamic system is to try to reduce the original infinite-dimensional system to an infinite-dimensional system. However,due to the unknown structure of the reduced system, it is difficult to describe its dynamical behaviour. To overcome this difficulty, the idea of approximate inertial manifolds is introduced, for NSE, the existence of AIM was studied, it is shown that the global attractor lies within a neighborhood of the graph of an Lipschitz function by the squeezing property. In this paper, by constructing a finite dimensional solution sequence, we will prove that it tends to the global attractor, theoretically, this provides a metod of constructing the asymptotic attractors, theoretically, this provides a method of constructing the asymptotic attractors for the evolution equations.  相似文献   

THE INDUSTRIAL ORGANIZATIONS AND THE L-S-BUSINESS STRATEGIES     

He Zonglu 《保鲜与加工》1992,(4):111-117

This papar presents an evolution model in business behaviors-the L-S Business Strategies,gives some examples and predictions which support these strategies,and analyzes the relationship between the industrial organizations in China and the L-S Business strategies.  相似文献   

如何建立成本分析模板服务一拖公司的产品结构调整     

周鹃 《拖拉机与农用运输车》2007,34(5):11-12,15

介绍一拖公司财务部在传统的成本分析理论基础上,建立了成本因素分析方法,为各单位产品成本管理和决策工作提供及时、快速的分析工具,并协助各单位找出影响利润的关键点,以改善盈利能力,提升产品竞争力;同时,建立完善了产品谱系盈利分析模板,引导一拖公司通过产品结构调整,提升集团公司的创利能力。  相似文献   

基于分解机制的多目标蝙蝠算法     

王亚辉  贾晨辉  赵仁鹏 《农业机械学报》2015,46(4):316-324

在分析蝙蝠算法性能基础上,将蝙蝠算法融入分解机制,提出了一种基于分解机制的多目标蝙蝠算法。为了进一步提高算法的多样性,将差分进化策略引入算法中。对14个具有复杂Pareto前沿的多目标优化问题(LZ-09系列和ZDT系列)测试不同邻域规模对算法性能的影响,结果表明新算法的邻域规模为20时性能最优;将其与MOEA/D-DE和NSGA-II算法进行对比分析,结果显示该算法的分布性、收敛性和多样性均优于另外两种算法。为了验证其求解含有约束问题的性能,将其应用于滑动轴承多目标优化设计问题中,获得的Pareto前沿分布均匀,表明算法具有工程实用性,是求解复杂高维多目标问题的有效方法。  相似文献   

基于对数相似度约束Otsu的自然场景病害果实图像分割     

赵瑶池  胡祝华 《农业机械学报》2015,46(11):9-15

针对自然场景下,由于复杂背景以及多变环境,水果病害果实图像分割难的问题,提出了一种基于对数相似度约束Otsu和水平集活动轮廓的近椭圆形病害果实图像分割方法。考虑背景的复杂多变,提出对数相似度约束Otsu分割来区分病害果实与背景;由于水平集活动轮廓模型的局部最优性,提出采用自适应膨胀系数的改进距离规则水平集活动轮廓模型来精确演化轮廓。先对病害果实区域样本的颜色进行混合高斯建模,获得整个病害果实图像与样本模型的对数相似度;对对数相似度进行约束Otsu阈值分割以及形态学滤波;采用最小二乘法对滤波后的曲线轮廓进行椭圆拟合,对拟合后的椭圆采用自适应膨胀系数的距离规则水平集活动轮廓演化,得到病害果实完整轮廓。对18个不同场景的病害果实进行分割,平均误判率和漏判率分别为1.77%和1.6%,实验结果表明,该方法可以从复杂自然场景图像中分割出病害果实。  相似文献