Chocolate spot: Pathogenicity dynamics, population diversity and host resistance to Botrytis fabae

蚕豆巧克力斑病是由蚕豆灰霉病菌（Botrytis fabae）引起的一种重要的蚕豆病害，可造成严重的作物损失。B。蚕豆的寄主范围很窄，蚕豆是经济上最重要的寄主。尽管在英国和其他地方已经鉴定出部分抗性品系，但目前还没有可用的抗性商业栽培品种。然而，目前尚不清楚这种耐药性是否普遍有效，或者是否存在菌株特异性。已发表的抗性筛选结果，包括部分抗性蚕豆品系，一直没有定论或相互矛盾，这表明可能是后者的情况。目的/方法：本项目将调查是否有对B的菌株特异性抗性。通过a）提高对宿主中遗传抗性的认识（在部分抗性品系中建立抗性的遗传基础），B）扩大对蚕豆中新抗性来源的筛选，以及通过c）研究病原体中的差异毒力，来产生蚕豆抗性。该项目还将研究宿主-病原体相互作用，通过构建从头基因组组装并将转录组学分析的读数映射到该基因组组装上来确定推定的效应分子。学生将尝试确定数量性状位点（QTL）的位置，并在选定的映射群体中确定巧克力斑点抗性的遗传基础。在更广泛的品种中筛选巧克力斑点抗性将有助于鉴定潜在的新抗性来源。结合鉴定宿主中的抗性来源，将探索病原体的遗传多样性和差异毒力的潜力。虽然B.虽然蚕豆灰霉病已被列入葡萄孢属的分类学研究，但迄今为止还没有进行大规模的研究来检查该病原体的遗传多样性。NIAB拥有一个稳定增长的收集超过200个英国分离的B。蚕豆，这将形成学生的努力，主要是在英国的人口B遗传多样性的基础。蚕豆。这将涉及通过筛选蚕豆的小组来鉴定差异毒力，以及在形态学，分子和基因组水平上研究病原体的多样性。该项目将使我们能够解决以下问题，包括：在英国和与其他国家相比，蚕豆葡萄孢菌的遗传多样性如何？是否存在不同的B菌株。不同毒力的蚕豆？这些在英国的地理分布如何，这种分布是否会随着时间的推移而变化，变化的程度如何？B中的哪些基因。蚕豆对致病性/致病性有贡献

Chocolate spot, caused by Botrytis fabae, is an important disease of faba bean (Vicia faba) which can cause severe crop losses. B. fabae has a narrow host range with faba bean being the most economically important host.Currently there are no resistant commercial cultivars available, although partially resistant lines have been identified in the UK and elsewhere. However, it is currently unknown if this resistance is universally effective or whether strain specificity occurs. Published results of resistance screens, including partially resistant faba bean lines, have been inconclusive or contradictory, which suggest that the latter may be the case.Aim/approach: This project will investigate whether strain -specific resistance to B. fabae occurs by a) improving the knowledge on genetic resistance in the host (establishing the genetic basis of resistance in partially resistant lines), b) extend screening for novel sources of resistance in Vicia faba, and by c) studying differential virulence in the pathogen. The project will also investigate host-pathogen interactions to identify putative effector molecules by constructing a de novo genome assembly and mapping reads from transcriptomic analyses onto this.The student will attempt to identify the location Quantitative trait loci (QTL) and characterise the genetic basis of resistance of chocolate spot resistance in selected mapping populations. Screening for chocolate spot resistance in a more extensive number of cultivars will aid identification of potential novel sources of resistance.In conjunction with identifying sources of resistance in the host, the genetic diversity and potential for differential virulence in the pathogen will be explored. Although B. fabae has been included in taxonomic studies of the Botrytis genus, no large-scale studies to examine this pathogen's genetic diversity have so far been undertaken . NIAB holds a steadily growing collection of more than 200 UK-isolates of B. fabae which will form the basis of the student's efforts to characterise the genetic diversity mainly within the UK's populations of B. fabae. This will involve the identification of differential virulence through screening of panels of Vicia faba as well as studying the pathogen's diversity on a morphological, molecular and genomic level.The project will enable us to address the following questions including:How genetically diverse is Botrytis fabae within the UK and compared to other countries??Are there distinct strains of B. fabae with differential virulence profile?How are these distributed geographically across the UK and does that distribution change over time and to what extent?Which genes in B. fabae are contributing to virulence/pathogenesis