Real Time deployment of pathogen resistance genes in rice

白叶枯病和稻瘟病是影响世界水稻产量的两大主要病原菌。品种抗性是保护水稻免受这些病原菌侵染的一种有效、可靠、环保的方法。现代分子育种技术的发展和应用，使水稻良种引种的世代从8-10年缩短到2-3年。这意味着，在单一遗传背景下，可以通过基因轮换或混合，实时部署具有各种抗性基因组合的抗病品种。目前育种项目产生的新品种将在两到三年内推出。这使得种植者可以获得一系列品种，每个品种都有独特的抗性基因组合。那么，一个关键问题是：这些品种应该部署在哪里？每个品种都应该部署在病原菌群体中不存在或频率极低的匹配毒力的地方。这确保了抗病品种在尽可能长的时间内保持有效。因此，我们需要一种方法来确定病原菌在田间是否存在或可能存在极低频率的毒力。因此，我们的目标是开发和应用一种结合建模和田间监测的方法来确定可以安全地部署新的抗性基因的区域，因为病原菌种群中的毒力出现的频率足够低。该方法：-1-将量化易感品种观察区中的感染人数。与新的抗病品种类似的小区将不会出现感染(理想情况下)。然后，使用统计方法，我们将能够估计田间病原菌种群中毒力的最大预期频率。如果这个频率足够小(例如10-10)，我们可以决定释放新的抗病品种。-2-将从田间水平扩大到区域水平。这将使我们能够在更大的空间尺度上做出关于品种发布的决定。该模型将根据对目前在泰国北部扩展的侵略性白叶枯病菌株的田间监测进行参数化。-3-将提供必要的培训，供未来用于水稻研究社区。-4-将开始与其开发一起使用，以帮助解决威胁泰国北部水稻生产的新的侵略性白叶枯病菌株所带来的新问题。该项目的输出将是一套方法，以确定在菲律宾和泰国哪里可以释放新的抗病品种，以最大限度地提高品种抗性的耐久性。这将对种植者有明显的好处，因为他们将较少受到打破新抗药性的毒力菌株的影响。这反过来将提高贫困种植者的收入。该项目还将对工作人员进行统计方法、流行病学建模和使用项目中开发的方法的培训。该项目还将通过向育种者提供田间病原菌毒力存在的信息来帮助他们建立育种目标。

Bacterial blight and rice blast are two key pathogens reducing rice productivity worldwide. Varietal resistance is an effective, reliable and environmentally friendly way of protecting rice against these pathogens. The development and use of modern molecular breeding techniques has shortened the generation of elite rice lines for varietal release from 8-10 years to 2-3 years. This means that real-time deployment of resistant varieties with various combinations of resistance genes can be customized through gene rotation or mixture in a single genetic background.New varieties resulting from current breeding projects will be released in two to three years. This makes a range of varieties each with a unique combination of resistance genes available to growers. A key question, then, is: Where should these varieties be deployed? Each variety should be deployed where the matching virulence is not present, or is at an extremely low frequency, in the pathogen population. This ensures that the resistant variety remains effective for the maximum possible time. We thus need a method to ascertain the absence, or possible presence in extremely small frequency, of pathogen virulence in the field.We therefore aim to develop and apply a combined modelling and field monitoring approach to determine areas where a novel resistance gene can safely be deployed because virulence is at a sufficiently low frequency in the pathogen population. The method:-1- Will quantify the number of infections in observational plots of a susceptible variety. A similar plot with the novel resistant variety will show no infections (ideally). Using a statistical method we will then be able to estimate the maximum expected frequency of virulence in a field pathogen population. If this frequency is small enough (e.g. 10-10) we can decide that the new resistant variety be released.-2- Will be scaled-up from the field level to a regional level. This will enable us to make decisions about variety release at larger spatial scales. The model will be parameterised from field monitoring of an aggressive bacterial blast strain currently expanding in the north of Thailand.-3- Will be made available, with the necessary training, for future use to the rice research community.-4- Will start to be used alongside its development to help solve the emerging problem posed by the new expanding aggressive bacterial blast strain that threatens northern Thailand's rice production.The outputs of the project will be a set of methods to establish where in the Philippines and Thailand novel resistant varieties can be released to maximise the durability of varietal resistance. This will be of clear benefit to growers as they will suffer less from virulent strains breaking the novel resistance. This in turn will improve the income of poor growers. The project will also train staff in statistical methods, epidemiological modelling and the use of the methods developed in the project. The project will also help breeders to establish breeding targets by providing them with information on the presence of pathogen virulence in the field.