Understanding the genetic control of Rhizosheath and its role in tolerance to abiotic stress in barley

到2050年，全球人口将达到90亿，而维持这一人口所需的资源正在减少，不可持续的农业实践和环境变化使我们不得不进行农业生产革命，以确保未来农业的可持续性。需要适应环境变化的新一代作物，培育这类作物的关键是识别和利用边际环境中产量的遗传变异。在造成这种产量变化的性状中，与根系有关的性状被认为具有很大的潜力。温带谷物，产生沿主要根轴及其侧枝粘在根毛上的土壤根鞘。根鞘质量取决于遗传和土壤因素，并与改善的磷酸盐和水分吸收有关。根鞘质量有潜力提供根毛生产和功能的快速综合筛选，特别有助于培育在减少投入农业中表现良好的营养和节水作物。先前的研究表明，根毛（长度、密度和形态）、根和微生物渗出物在根鞘形成中起作用。此外，我们已经表明，在干旱条件下，根毛长度和根鞘产量都能促进资源获取。现在需要了解根鞘质量的遗传和生物物理基础，以及它们如何相互作用以影响水和养分的吸收。根鞘质量有潜力作为一种新的功能性状，可以快速筛选，以确定作物对营养和水分亏缺的遗传和生理控制。该项目将利用大量的基因组和遗传资源，最初的重点是由国家和推荐品种组成的两行春大麦协会小组，可以在欧洲的许多环境中进行田间试验。该项目旨在了解控制根鞘质量的性状和基因。具体来说，候选人将1)进行根鞘性状（根毛和分泌物）的关联研究，以验证和扩展我们关于根鞘质量基因型变异的初步数据，并确定候选基因。2)确定根毛性状和分泌物在根鞘团中的生理作用及其受环境条件的影响。3)在对照环境和田间条件下，研究营养缺乏和干旱条件下根鞘质量与植株生产性能的关系。4)开发根鞘性状的标记，在预育种和育种环境中进行检测。

With global population set to hit nine billion by 2050 and the resources needed to sustain this population diminishing, unsustainable agronomic practices and environmental change have brought us to the point where a revolution in agricultural production is necessary to ensure future agricultural sustainability. A new generation of crops adapted to environmental change is needed and the key to breeding such crops is the identification and utilisation of genetic variation in yield in marginal environments. Of the traits responsible for this yield variation, those associated with roots are perceived to have great potential. Temperate cereals, produce rhizosheaths of soil that stick to root hairs along main root axes and their lateral branches. Rhizosheath mass depends on both genetic and soil factors and has been associated with improved phosphate and water uptake. Rhizosheath mass has the potential to provide a rapid integrative screen for root hair production and functionality, particularly useful for breeding nutrient- and water-efficient crops that perform well in reduced-input agriculture. Previous research has revealed that root hairs (length, density, and morphology) and root and microbial exudates play a role in rhizosheath formation. In addition, we have shown that both root hair length and rhizosheath production improve resource acquisition in drought conditions. Understanding the genetic and biophysical bases of rhizosheath mass, and how these interact to influence water and nutrient uptake is now required. Rhizosheath mass has potential as a novel functional trait that can be screened rapidly to determine the genetic and physiological controls of crop tolerance to nutrient and water deficit. The project will take advantage of considerable genomic and genetic resources with initial focus on two row spring barley association panel assembled from national and recommended list culitvars, with access to field trials that can be run across many environments in Europe. The project aims to understand traits and genes that control rhizosheath mass. Specifically, the candidate will 1) Undertake association studies of rhizosheath traits (root hair and exudates) to validate and extend our preliminary data on genotypic variation in rhizosheath mass and identify candidate genes. 2) Determine the physiological roles of root hair traits and exudates in rhizosheath mass and how these are influenced by environmental conditions. 3) Test the association of rhizosheath mass with plant performance under nutrient-deficit and drought in both controlled environments and in the field. 4) Develop markers for the rhizosheath trait to be tested in a prebreeding and breeding environment.