Multiple Herbicide Resistance in Grass Weeds: from Genes to AgroEcosystems

在北欧先进的农业生产系统中，谷类作物的杂草控制已成为可持续集约化的最大挑战之一，造成的产量损失和投入成本高于所有其他生物制约因素(病虫害)。北欧谷物中最有问题的杂草是野草，特别是黑草(Alopecurus Myosuroides)，由于除草剂抗药性的进化，这种杂草在过去30年里变得越来越难以控制。这种抗性有两种形式：1)靶点抗性(TSR)，即杂草对除草剂高度耐受，原因是这些化学物质靶标的蛋白质发生突变，使杂草对除草剂的抑制不那么敏感。2)代谢或多重除草剂抗性(MHR)，由于对作物保护剂解毒能力的普遍提高，杂草对各种除草剂的耐受性变得更强，无论其化学成分或作用方式如何。虽然TSR现在已经被很好地理解了，并且可以通过轮用不同作用模式的除草剂来对抗，但促进MHR的分子基础和进化驱动因素却知之甚少，而且相关的杂草很难用传统的方法进行控制。在这个为期4年的项目中，我们建议使用分子生物学和生物化学、生态学和进化、建模和综合害虫管理相结合的方法来开发更好的工具来监测和管理田间条件下黑草的TSR和MHR。该项目代表了一种新的农业系统方法，将我们对除草剂抗性的分子生物学的最新了解与基于数量遗传学方法的农场监测和建模联系起来，以确定不同干预措施的有效性。通过一个多学科联盟，我们将在分子和生化水平上整合关于MHR和TSR的知识，并将这种基本理解与现场观察到的耐药性表型联系起来。选择和育种实验将研究抗性选择的动态，目的是首次确定MHR的遗传结构及其与其他逆境和生活史性状的关系。来自田间监测和温室研究的数据将被整合到生态、进化和管理模型中，最终目的是设计新的管理措施，以防止、推迟或减轻除草剂抗性的演变。最后，将探讨新型管理对环境和经济的影响。因此，该项目的主要目标是使用最先进的方法，跨越分子生物学、杂草科学、建模和农学，在方案的生命周期内提供新的抗性控制措施。该项目分为5个综合工作包，将处理以下问题1。代谢性除草剂抗性进化的分子机制是什么？2.英国黑草种群中除草剂抗性问题的程度如何？抗性对黑草种群和作物产量有什么影响？3.促进和制约除草剂抗性产生的遗传、生态和农艺因素是什么？4.如何利用应用的进化模型来管理除草剂抗性？5.新杂草和抗性管理策略的经济和环境后果是什么？主要成果将是：1.用于农场除草剂抗性表征的快速诊断工具。对黑草中主要除草剂作用方式的抗性程度和抗性分布进行了抗性审计。一套解决抗药性产生和管理中的关键问题的模型。管理建议以及对其影响的分析。

In the advanced agricultural production systems of Northern Europe, weed control in cereal crops has become one of the greatest challenges to sustainable intensification, accounting for higher yield losses and greater input costs than all other biological constraints (pests and diseases). The most problematic weeds in cereals in Northern Europe are the wild grasses, notably black-grass (Alopecurus myosuroides), which has become steadily more difficult to control over the last 30 years due to the evolution of herbicide resistance. This resistance assumes two forms: 1) Target site resistance (TSR), whereby the weeds become highly tolerant of herbicides due to mutations in the proteins targeted by these chemicals rendering them less sensitive to inhibition by that herbicide mode of action. 2) Metabolic or multiple herbicide resistance (MHR) where weeds become more tolerant of a broad range of herbicides, irrespective of their chemistry or mode of action, due to a general enhancement in the ability to detoxify crop protection agents. While TSR is now quite well understood and can be countered by the rotational use of herbicides with differing modes of action, the molecular basis and evolutionary drivers which promote MHR are poorly understood and the associated grass weeds very difficult to control using conventional methods. In this 4 year project, we propose to use a combination of molecular biology and biochemistry, ecology and evolution, modeling and integrated pest management to develop better tools to monitor and manage both TSR and MHR in black-grass under field conditions. The project represents a novel agri-systems approach, linking our latest understanding in the molecular biology of herbicide resistance to on farm monitoring and modeling based on a quantitative genetics approach to define the effectiveness of different intervention measures. Through a multidisciplinary consortium, we will integrate knowledge about MHR and TSR at the molecular and biochemical levels and relate this fundamental understanding to resistance phenotypes observed in the field. Selection and breeding experiments will examine the dynamics of selection for resistance, with the intention of determining the genetic architecture of MHR for the first time and its relation to other stresses and life history traits. Data from field monitoring and glasshouse studies will be integrated in ecological, evolutionary and management models with the ultimate aim to design novel management to prevent, delay or mitigate the evolution of herbicide resistance. Finally, the environmental and economic impacts of novel management will be explored. The project therefore has the primary goal of using state of the art approaches spanning molecular biology, weed science, modeling and agronomy to provide new resistance control measures within the life of the programme. The project is divided into 5 integrated work packages which will address the following questions1. What are the molecular mechanisms that underpin the evolution of metabolic herbicide resistance?2. What is the extent of the herbicide resistance problem in UK black-grass populations and what impacts is resistance having on black-grass populations and crop yields?3. What are the genetic, ecological and agronomic factors that promote and constrain the emergence of herbicide resistance?4. How can applied evolutionary models be used to manage herbicide resistance?5. What are the economic and environmental consequences of novel weed and resistance management strategies?The major outputs will be:1. A rapid diagnostic toolkit for the on-farm characterisation of herbicide resistance.2. A resistance audit for the extent and distribution of resistance to the major herbicide modes of action in black-grass.3. A suite of models to address key questions in the emergence and management of resistance.4. Management recommendations, together with an analysis of their impacts.